ES


Line plots across dimensions of each concept
Line plots across concepts
Tables

Table of contents



us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
dei:LegalEntity

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:InterestExpense
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:NetIncomeLoss
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NonoperatingIncomeExpense
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByAssetClass
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:FairValueByAssetClass

us-gaap:OperatingExpenses
dei:LegalEntity

us-gaap:OperatingIncomeLoss
dei:LegalEntity
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

us-gaap:Revenues
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidationItems
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:Assets
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:LiabilitiesAndStockholdersEquity
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:StockholdersEquity
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:ConsolidatedEntities
us-gaap:StatementEquityComponents

us-gaap:AssetsCurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:Cash
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:CashAndCashEquivalentsAtCarryingValue
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity

us-gaap:AccountsReceivableNetCurrent
dei:LegalEntity

us-gaap:InventoryRawMaterialsAndSupplies
dei:LegalEntity

us-gaap:OtherAssetsCurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:Goodwill
us-gaap:BusinessAcquisition
us-gaap:StatementBusinessSegments

us-gaap:OperatingLeaseRightOfUseAsset
dei:LegalEntity

us-gaap:OtherAssetsNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:EquitySecuritiesFvNi
dei:LegalEntity

us-gaap:AccountsPayableCurrent
dei:LegalEntity

us-gaap:LiabilitiesCurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:LongTermDebtCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:ConsolidatedEntities
us-gaap:LongtermDebtType

us-gaap:OperatingLeaseLiabilityCurrent
dei:LegalEntity

us-gaap:OtherLiabilitiesCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:RegulatoryAsset
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:LongTermDebt
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis
us-gaap:LongtermDebtType

us-gaap:LongTermDebtNoncurrent

us-gaap:DeferredIncomeTaxLiabilitiesNet
dei:LegalEntity

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:RetirementPlanType

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:OperatingLeaseLiabilityNoncurrent
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive
dei:LegalEntity

us-gaap:OperatingLeaseLiability
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
dei:LegalEntity

us-gaap:StockholdersEquity
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:ConsolidatedEntities
us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities

us-gaap:AdditionalPaidInCapital
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:RetainedEarningsAccumulatedDeficit
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:TreasuryStockValue
us-gaap:ConsolidatedEntities

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
dei:LegalEntity

us-gaap:DeferredIncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:DepreciationDepletionAndAmortization
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInAccountsPayable
dei:LegalEntity

us-gaap:IncreaseDecreaseInInventories
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetIncomeLoss
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment
dei:LegalEntity
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:PaymentsOfDividendsCommonStock
dei:LegalEntity

us-gaap:DeferredTaxLiabilities
dei:LegalEntity

us-gaap:DeferredTaxAssetsNet
dei:LegalEntity

us-gaap:UnrecognizedTaxBenefits
dei:LegalEntity

us-gaap:DeferredTaxAssetsValuationAllowance
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfShortTermDebt
dei:LegalEntity

es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal
dei:LegalEntity
dei:LegalEntity, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
dei:LegalEntity
es:AmortizationOfRegulatoryAssetLiabilities
us-gaap:RelatedPartyTransactionsByRelatedParty
es:AmountOfNaturalGasTransmissionPurchased
dei:LegalEntity
es:AmountofEnergytobePurchasedUnderRenewableEnergyContract

es:AmountofNaturalGasToBePurchasedUnderFuturesContracts
us-gaap:RetirementPlanType
es:DefinedBenefitPlanImpactonLiabilityasaResultofChangeinDiscountRate

es:DerivativeInstrumentsGainLossRecognizedInRegulatoryAssetLiability

es:EnergyEfficiencyPrograms
dei:LegalEntity

es:EnvironmentalSiteQuantity
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel
es:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityGainLossIncludedInRegulatoryAssetLiability
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
es:GainLossOnDispositionOfPropertyPlantAndEquipmentNetOfTax

es:IncrementalCommonSharesAttributableToDilutiveEffectOfShareBasedPaymentArrangementsAndOther
dei:LegalEntity, us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencyAmountAssociatedWithFirstComplaintRefunded
us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencyBaseROESubsequentlyAuthorizedbyFERCforFirstComplaintPeriodandProspectivelyFromOctober2014

es:LossContingencyPercentageOfBaseROEReasonablyJustified

es:LossContingencyPercentageOfIncentiveCapOnTotalROE
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencyPercentageofROEforAnyIncentiveProject
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencySensitivityAnalysis90BasisPointDecreaseInReturnOnEquityImpactOnAnnualIncomeLoss
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencySensitivityAnalysis90BasisPointDecreaseInReturnOnEquityImpactOnAnnualRevenues
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
dei:LegalEntity
es:NoncontrollingInterestIncreaseinContributionsFromParent
dei:LegalEntity, us-gaap:StatementEquityComponents

es:NumberofElectricNaturalGasAndWaterCustomers
dei:LegalEntity
es:PensionSERPandPBOPExpenseNetofContributions
us-gaap:LossContingenciesByNatureOfContingency
es:PercentageofBaseROEofComplaintPeriod
dei:LegalEntity, us-gaap:RegulatoryAgency
es:PublicUtilitiesFirstStepAdjustmentApprovedRevenueRequirement
dei:LegalEntity, us-gaap:RegulatoryAgency
es:PublicUtilitiesRateMattersGainLossOnRateChange
dei:LegalEntity, us-gaap:RetirementPlanType
es:RelatedIntercompanyAllocationsofDefinedBenefitExpense

es:RepaymentsOfRateReductionBonds
dei:LegalEntity
dei:LegalEntity, us-gaap:UnusualOrInfrequentItem
es:ReversalOfDeferredNetIncrementalCOVID19Costs
dei:LegalEntity, es:UnrecordedUnconditionalPurchaseObligationContractName, us-gaap:Range, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
es:UnrecordedUnconditionalPurchaseObligationAnnualAmount

es:UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed
dei:LegalEntity
dei:LegalEntity, us-gaap:UnusualOrInfrequentItem
us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
us-gaap:UnusualOrInfrequentItem

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries
dei:LegalEntity
dei:LegalEntity, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs
dei:LegalEntity
dei:LegalEntity, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

us-gaap:AmortizationOfDeferredCharges
dei:LegalEntity
us-gaap:AmortizationOfRegulatoryAsset
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationConsiderationTransferred1
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
us-gaap:BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCostExpensed
us-gaap:BusinessCombinationSeparatelyRecognizedTransactions
us-gaap:BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized

us-gaap:CapitalExpendituresIncurredButNotYetPaid
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
dei:LegalEntity
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost
us-gaap:RetirementPlanType

us-gaap:Depreciation
dei:LegalEntity

us-gaap:DividendsCommonStock
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:DividendsPreferredStock
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss

us-gaap:ExciseAndSalesTaxes
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:GainLossOnSaleOfPropertyPlantEquipment
us-gaap:FairValueByAssetClass
us-gaap:IncomeLossFromEquityMethodInvestments

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables
dei:LegalEntity
dei:LegalEntity
us-gaap:IncreaseDecreaseInDueToRelatedParties

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable
dei:LegalEntity

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
dei:LegalEntity

us-gaap:IncrementalCommonSharesAttributableToEquityForwardAgreements

us-gaap:OperatingLeaseLeaseIncome
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
dei:LegalEntity

us-gaap:OtherNoncashIncomeExpense
dei:LegalEntity

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock
dei:LegalEntity

us-gaap:PaymentsToAcquireEquityMethodInvestments

us-gaap:PaymentsToAcquireMarketableSecurities

us-gaap:PensionAndOtherPostretirementBenefitContributions
dei:LegalEntity

us-gaap:PensionAndOtherPostretirementBenefitExpense
dei:LegalEntity
dei:LegalEntity
us-gaap:ProceedsFromContributionsFromParent

us-gaap:ProceedsFromIssuanceOfCommonStock
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:ProceedsFromIssuanceOfDebt
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity
us-gaap:ProceedsFromNotesPayable

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromSaleAndMaturityOfMarketableSecurities
us-gaap:BalanceSheetLocation, us-gaap:DisposalGroupClassification
us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:ProvisionForDoubtfulAccounts
dei:LegalEntity
dei:LegalEntity, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
dei:LegalEntity, us-gaap:RegulatoryAgency
us-gaap:PublicUtilitiesApprovedEquityCapitalStructurePercentage
us-gaap:RegulatoryAgency
dei:LegalEntity, us-gaap:RegulatoryAgency
us-gaap:PublicUtilitiesApprovedRateIncreaseDecreaseAmount
us-gaap:StatementScenario, us-gaap:RegulatoryAgency
dei:LegalEntity, us-gaap:RegulatoryAgency
us-gaap:PublicUtilitiesApprovedReturnOnEquityPercentage
us-gaap:RegulatoryAgency
dei:LegalEntity, us-gaap:RegulatoryAgency
us-gaap:PublicUtilitiesRequestedRateIncreaseDecreaseAmount

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
us-gaap:StatementEquityComponents

us-gaap:RevenueNotFromContractWithCustomer
dei:LegalEntity, us-gaap:ConsolidationItems
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:RevenueNotFromContractWithCustomerOther
dei:LegalEntity, us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueTreasuryStockReissued
us-gaap:StatementEquityComponents

us-gaap:TaxesExcludingIncomeAndExciseTaxes
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseMaintenanceAndOperations
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseOther
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:WeightedAverageNumberDilutedSharesOutstandingAdjustment

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity
us-gaap:RetirementPlanType
es:AmortizationPriorServiceCostfromRegAsset

es:AmountofCapacityProvidedUnderCapacityContract
us-gaap:BusinessAcquisition
es:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedEnergyReliefFundLiability
us-gaap:BusinessAcquisition
es:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesExcludingLongTermDebt
us-gaap:BusinessAcquisition
es:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedReserveForArrearageForgivenessCurrent
us-gaap:BusinessAcquisition
es:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRestrictedCashAndCashEquivalents
us-gaap:BusinessAcquisition
es:BusinessCombinationTargetWorkingCapitalAmount
dei:LegalEntity, us-gaap:LongtermDebtType
es:Capacityavailableunderpreferredstockprovisions
us-gaap:IncomeTaxAuthority
es:CharitableContribution
us-gaap:Range
es:ContractualObligationEstimatedAnnualCost
dei:LegalEntity
es:DebtInstrumentApprovedForIssuanceFaceAmount
dei:LegalEntity, us-gaap:SubsequentEventType
es:DebtInstrumentAuthorizedAmountAvailableForIssuance
dei:LegalEntity
es:DebtInstrumentRequestedForIssuanceFaceAmount

es:DeferredCompensationCashBasedArrangementsExpensePertainingToDeferredBenefits
dei:LegalEntity
dei:LegalEntity, us-gaap:UnusualOrInfrequentItem
es:DeferredRegulatoryCosts
us-gaap:UnusualOrInfrequentItem

es:DeferredRegulatoryCostsFacilitiesAndFleetCleaningSanitizingCostsAndSupplies
dei:LegalEntity

es:DeferredRegulatoryCostsUncollectibleExpensesIncurred
dei:LegalEntity
us-gaap:UnusualOrInfrequentItem

es:DeferredTaxAssetPurchaseAccounting

es:DeferredTaxAssetsTaxEffectTaxRegulatoryLiabilities
dei:LegalEntity

es:DeferredTaxLiabilitiesGoodwillRegulatoryAsset
dei:LegalEntity

es:DeferredTaxLiabilitiesRegulatoryAssetsDerivativeAssets
dei:LegalEntity

es:DeferredTaxLiabilitiesRegulatoryAssetsOtherRegulatoryDeferrals
dei:LegalEntity

es:DeferredTaxLiabilitiesRegulatoryAssetsTaxEffectTaxRegulatoryAssets
dei:LegalEntity

es:DeferredTaxLiabilitiesResultingFromPropertyTaxAccrualsAndOther
dei:LegalEntity
dei:LegalEntity, us-gaap:RetirementPlanType
es:DefinedBenefitPlanBenefitsPaidLumpSum
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
es:DefinedBenefitPlanFairValueofPlanAssetsUncategorized
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
es:DefinedBenefitPlanPaymentsSerp
us-gaap:RetirementPlanType
us-gaap:BalanceSheetLocation, us-gaap:RetirementPlanType
es:DefinedBenefitPlanPrepaidAssets

es:ElectricAndNaturalGasUtilityAccumulatedDepreciation
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
es:EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquityGoodwill
us-gaap:RetirementPlanType
es:GainLossArisingDuringYearRegulatoryAsset

es:InterestIncludedInPaymentToSettleSpentNuclearFuelObligation
dei:LegalEntity, us-gaap:SubsequentEventType
es:LengthOfNaturalGasPipeline
us-gaap:BusinessAcquisition
dei:LegalEntity
es:LongTermReceivableFromNusco

es:Longtermdebtmaturitiesrepaymentsofprincipaltotal
dei:LegalEntity
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
es:LossContingencyAccidentReportingViolationFines
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
es:LossContingencyAfterTaxEarningsImpactPerShare

es:LossContingencyAllowedRateOfROE
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencyEstimateOfPossibleLossAccidentReportingViolationFines
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencyEstimateOfPossibleLossNonComplianceFine
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
es:LossContingencyNonComplianceFine
us-gaap:RetirementPlanType
es:LossesReclassifedFromRegAssetPreTax
dei:LegalEntity
es:MaximumLoansReceivableOutstanding
dei:LegalEntity, us-gaap:SubsequentEventType
es:NumberOfCommunitiesServiced
us-gaap:BusinessAcquisition

es:NumberOfNaturalGasCustomers
dei:LegalEntity, us-gaap:SubsequentEventType
us-gaap:BusinessAcquisition
us-gaap:SubsequentEventType

es:OtherAccumulatedDepreciation
dei:LegalEntity
es:PensionAndOtherPostretirementDefinedBenefitPlansAssetsNoncurrent
us-gaap:RetirementPlanType
es:PriorServiceCostCreditArisingDuringPeriodRegulatoryAsset

es:PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress
dei:LegalEntity
us-gaap:RegulatoryAgency
es:PublicUtilitiesApprovedRate
us-gaap:BalanceSheetLocation, us-gaap:RegulatoryAgency
es:PublicUtilitiesDivestitureCostsToBeRecovered
us-gaap:RegulatoryAgency

es:PublicUtilitiesPropertyPlantAndEquipmentDistributionNaturalGas

es:PublicUtilitiesPropertyPlantAndEquipmentDistributionWater

es:PublicUtilitiesPropertyPlantAndEquipmentElectricAndNaturalGasUtilityTotal

es:PublicUtilitiesPropertyPlantAndEquipmentElectricNaturalGasandWaterUtilityTotal

es:PublicUtilitiesPropertyPlantandEquipmentAccumulatedDepreciationElectricNaturalGasandWaterUtility

es:PublicUtilitiesPropertyPlantandEquipmentAccumulatedDepreciationOther

es:RateReductionBonds
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis

es:RateReductionBondsCurrent
dei:LegalEntity
us-gaap:RetirementPlanType
es:RegulatoryAssetPriorServiceCost
us-gaap:RetirementPlanType
es:Regulatoryassetgainslossesbeforetax
dei:LegalEntity
es:RenewablePortfolioStandardsComplianceObligation
us-gaap:AwardType
es:SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedandVestedWeightedAverageGrantDateFairValue
dei:LegalEntity
es:Shorttermborrowinglimitapprovedbyregulatoryagency

es:SocialSecurityTaxEmployerDeferralCARESAct
dei:LegalEntity
us-gaap:AccountsPayableOtherCurrent
dei:LegalEntity
us-gaap:AccountsPayableRelatedPartiesCurrent
us-gaap:ConsolidatedEntities
dei:LegalEntity
us-gaap:AccountsReceivableRelatedPartiesCurrent
us-gaap:ConsolidatedEntities

us-gaap:AccrualForEnvironmentalLossContingencies
dei:LegalEntity
dei:LegalEntity, us-gaap:EnvironmentalRemediationSite
us-gaap:EnvironmentalRemediationSite
us-gaap:EnvironmentalRemediationSite
us-gaap:AccrualForEnvironmentalLossContingenciesComponentAmount

us-gaap:AllowanceForDoubtfulAccountsReceivable
dei:LegalEntity
dei:LegalEntity, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
dei:LegalEntity, us-gaap:Restatement, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
dei:LegalEntity, us-gaap:UnusualOrInfrequentItem
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
us-gaap:UnusualOrInfrequentItem

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity

us-gaap:AmountOfRegulatoryCostsNotYetApproved
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset

us-gaap:AssetRetirementObligation
dei:LegalEntity

us-gaap:AssetRetirementObligationsNoncurrent

us-gaap:AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue

us-gaap:AvailableForSaleSecuritiesDebtSecurities
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationContingentConsiderationLiability
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:ContractualObligation
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
us-gaap:DebtInstrumentFaceAmount
dei:LegalEntity, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet
us-gaap:LongtermDebtType

us-gaap:DeferredCompensationCashbasedArrangementsLiabilityClassifiedNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:DeferredFinanceCostsNet
us-gaap:LongtermDebtType
us-gaap:ConsolidatedEntities
us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredTaxAssetsDerivativeInstruments
dei:LegalEntity

us-gaap:DeferredTaxAssetsGross
dei:LegalEntity

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards

us-gaap:DeferredTaxAssetsOther
dei:LegalEntity

us-gaap:DeferredTaxAssetsRegulatoryAssetsAndLiabilities
dei:LegalEntity

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits
dei:LegalEntity

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesOther
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment
dei:LegalEntity
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax
us-gaap:Range, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
us-gaap:Range, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan
us-gaap:BalanceSheetLocation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanName, us-gaap:RetirementPlanType
us-gaap:RetirementPlanName, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations
dei:LegalEntity
us-gaap:DepositsAssetsCurrent
dei:LegalEntity, us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeAssetFairValueGrossLiability
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:MeasurementInputType
us-gaap:DerivativeAssetLiabilityNetMeasurementInput
dei:LegalEntity, us-gaap:Range, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:MeasurementInputType
dei:LegalEntity, us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeFairValueOfDerivativeAsset
dei:LegalEntity, us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
dei:LegalEntity, us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
dei:LegalEntity, us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
dei:LegalEntity
us-gaap:DerivativeLiabilitiesCurrent

us-gaap:DerivativeLiabilitiesNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeLiabilityFairValueGrossAsset
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:BalanceSheetLocation, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupIncludingDiscontinuedOperationGoodwill1
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:BalanceSheetLocation, us-gaap:DisposalGroupClassification
us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentDifferenceBetweenCarryingAmountAndUnderlyingEquity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOwnershipPercentage

us-gaap:EquityMethodInvestments
us-gaap:ConsolidatedEntities
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue

us-gaap:FinanceLeaseLiability
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityCurrent
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityNoncurrent
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDue
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDueAfterYearFive
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount
dei:LegalEntity

us-gaap:FinanceLeaseRightOfUseAsset
dei:LegalEntity

us-gaap:FinanceLeaseWeightedAverageDiscountRatePercent
dei:LegalEntity
us-gaap:CounterpartyName, us-gaap:GuaranteeObligationsByNature
us-gaap:GuaranteeObligationsMaximumExposure
us-gaap:GuaranteeObligationsByNature
dei:LegalEntity
us-gaap:IncomeTaxReceivable
dei:LegalEntity
us-gaap:IncomeTaxesReceivable
dei:LegalEntity
us-gaap:InterestPayableCurrent

us-gaap:InventoryGross
dei:LegalEntity

us-gaap:InvestmentsFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
dei:LegalEntity

us-gaap:LiabilitiesOtherThanLongtermDebtNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity
us-gaap:ConsolidatedEntities, us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtType

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
dei:LegalEntity
dei:LegalEntity, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingencyEstimateOfPossibleLoss
us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
dei:LegalEntity
us-gaap:MarketableSecurities

us-gaap:MarketableSecuritiesNoncurrent
dei:LegalEntity
us-gaap:NotesAndLoansReceivableNetCurrent
dei:LegalEntity
us-gaap:NotesAndLoansReceivableNetNoncurrent

us-gaap:NotesPayable
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities, us-gaap:ShortTermDebtType
dei:LegalEntity
us-gaap:NotesPayableRelatedPartiesClassifiedCurrent
dei:LegalEntity
us-gaap:NotesPayableRelatedPartiesCurrentAndNoncurrent
us-gaap:ConsolidatedEntities
us-gaap:NotesReceivableRelatedPartiesCurrent
us-gaap:ConsolidatedEntities
us-gaap:NotesReceivableRelatedPartiesNoncurrent

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent
dei:LegalEntity
us-gaap:IncomeTaxAuthority
us-gaap:OperatingLossCarryforwards
dei:LegalEntity, es:TypeOfInventoryByMajorAssetClass
us-gaap:OtherInventoryCapitalizedCosts
es:TypeOfInventoryByMajorAssetClass

us-gaap:PreferredStockValueOutstanding
dei:LegalEntity, us-gaap:StatementClassOfStock
dei:LegalEntity
us-gaap:PrepaidTaxes
dei:LegalEntity
us-gaap:PublicUtilitiesAmountOfAllowanceForEarningsOnEquityCapitalizedForRateMakingPurposes

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDistribution
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentNet
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentPlantInService
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentTransmission
dei:LegalEntity

us-gaap:ReceivablesFromCustomers
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligation
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligationDueAfterFifthYear
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligationDueInFifthYear
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligationDueInFourthYear
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligationDueInSecondYear
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligationDueInThirdYear
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:RecordedUnconditionalPurchaseObligationDueWithinOneYear
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:RedeemableNoncontrollingInterestEquityPreferredCarryingAmount
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis

us-gaap:RegulatoryAssets

us-gaap:RegulatoryAssetsCurrent
dei:LegalEntity

us-gaap:RegulatoryAssetsNoncurrent
dei:LegalEntity

us-gaap:RegulatoryLiabilities
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryLiability
us-gaap:RegulatoryLiability

us-gaap:RegulatoryLiabilityCurrent
dei:LegalEntity

us-gaap:RegulatoryLiabilityNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:RegulatoryAsset
us-gaap:CounterpartyName
us-gaap:RestrictedCash
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:RestrictedCashAndCashEquivalents
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:BalanceSheetLocation
us-gaap:BalanceSheetLocation

us-gaap:RetainedEarningsUnappropriated
dei:LegalEntity
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ShortTermBorrowings
us-gaap:ShortTermDebtType
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtWeightedAverageInterestRate
us-gaap:ConsolidatedEntities, us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtType
dei:LegalEntity, us-gaap:IncomeTaxAuthority
us-gaap:TaxCreditCarryforwardAmount
us-gaap:IncomeTaxAuthority

us-gaap:UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:LongTermContractForPurchaseOfElectricPower
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear
dei:LegalEntity, us-gaap:ValuationAllowancesAndReservesType
us-gaap:ValuationAllowancesAndReservesBalance
us-gaap:ValuationAllowancesAndReservesType

Plots across concepts


IncomeStatement
Other Comprehensive Income Loss Net Of Tax
Expenses
Income Tax Expense Benefit
Balance Sheet
Operating Lease Liability
Assets
Operating Lease Right Of Use Asset
Current Assets
Other Assets Current
NonCurrent Assets
Operating Lease Right Of Use Asset
Liabilities
Operating Lease Liability
Current Liabilities
Operating Lease Liability Current
Noncurrent Liabilities
Operating Lease Liability Noncurrent
Stockholders Equity
Accumulated Other Comprehensive Income Loss Net Of Tax
CashFlow
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInOperatingActivities
Increase Decrease In Inventories
NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInFinancingActivities
Proceeds From Payments For Other Financing Activities
Shares
Weighted Average Number Of Shares Outstanding Basic
OperatingLeaseLiability
Operating Lease Liability Current
NonoperatingIncomeExpense
Nonoperating Income Expense
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Payments Due Year Four
AccountsReceivable
Allowance For Doubtful Accounts Receivable Current

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:CommonStockValue █████▆▅▃▃▁▁▁▁▁1789.0921789.0921789.0921789.0921789.0921759.0921729.2921699.2921699.2921669.3921669.3921669.3921669.3921669.392
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁344.435696344.334689NA343.773602338.561649332.937153NA326.008342320.38849318.316082NA317.967311317.885187317.992999
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁343.844626343.678243NA343.076614337.946663331.102237NA324.037169319.664998317.624593NA317.36011317.344596317.397052
us-gaap:EarningsPerShareBasic ▆█▆█▆█▆▇▁▇▆▇▆▆0.771.070.791.010.751.010.770.980.10.970.730.910.760.85
us-gaap:EarningsPerShareDiluted ▆█▆█▆█▆▇▁▇▆▇▆▆0.771.060.791.010.751.010.760.980.10.970.730.910.760.85
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
 EBT margin dei:LegalEntity es:NstarElectricCompany▂▃▁▆▁▃▂▆▂▄▂█▂▄687.375737.043670.974875.371660.971733.833686.4878.669681.893797.6712.6939.46690.7770.127
 EBT margin dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH▆█▄▇▃▆▅▆▁▆278.849293.435263.834283.669255.224276.368268.2280.4240.9276.4NANANANA
 EBT margin dei:LegalEntity es:TheConnecticutLightAndPowerCompany▄█▄█▄▆▃▅▂▅▂▅▁▃829.597987.274836.133994.27817.421899.703788.7853.943740.846849.246751.3865.028694.9784.983
 Operating Margin dei:LegalEntity es:NstarElectricCompany▂▃▁▆▁▃▂▆▂▄▂█▂▄687.375737.043670.974875.371660.971733.833686.4878.669681.893797.6712.6939.46690.7770.127
 Operating Margin dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH▆█▄▇▃▆▅▆▂▆▃█▁▅278.849293.435263.834283.669255.224276.368268.2280.4240.9276.4254.9290.2235.1267.4
 Operating Margin dei:LegalEntity es:TheConnecticutLightAndPowerCompany▄█▄█▄▆▃▅▂▅▂▅▁▃829.597987.274836.133994.27817.421899.703788.7853.943740.846849.246751.3865.028694.9784.983
 Operating Margin us-gaap:ConsolidationItems us-gaap:CorporateNonSegment▇██▇▄▅▃▃▃▃▂▁▂▁330.0343.0335.2322.3283.8294.6261.4258.1250.8258.1243.8224.6237.0230.9
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,es:EversourceElectricDistribution▃▆▂█▂▅▂▆▁▅▂█▁▄1676.51900.31650.42060.31616.21805.31649.31931.61561.81833.91635.42027.41539.91754.6
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,es:EversourceElectricTransmission█▇▇▇▆▅▄▄▄▃▃▃▂▁411.2400.6400.5389.3376.7369.7351.1347.8349.6340.5333.3330.6317.4305.0
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,es:EversourceWater▄▂▂█▅▂▃█▄▁▃█▄▁52.846.448.864.155.546.951.164.253.745.550.563.553.544.6
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,es:NaturalGasDistribution▃█▄▁▂▅▃▁▂▅▃▁▂▄311.8780.5438.7110.2211.2448.6282.3103.4207.7468.9281.7109.0206.5424.9
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:ComprehensiveIncomeNetOfTax ▆█▆█▆▇▅▇▁▇▅▆▅▆265.401367.331255.909348.421252.785336.701236.995320.50835.617310.874230.889290.786244.909272.819
us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest ▄▄▄▄▄▄▄▄▄▄▄▄▄▄1.881.881.881.881.881.881.881.881.881.881.881.881.881.88
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic ▆█▆█▅▇▅▇▁▇▅▆▅▆352.789482.003344.368456.382329.613428.509330.981400.9964.149393.951301.671357.538315.099355.192
us-gaap:IncomeTaxExpenseBenefit ▆█▄█▅▆▅▅▁▅▄▄▄▅86.389113.9870.565108.24275.50191.87679.06480.22630.81583.39368.47566.27870.45283.766
us-gaap:InterestExpense █▆▅▅▅▅▅▅▄▄▂▂▃▁145.435137.766135.385134.066134.285134.715133.543135.216132.705131.7126.071125.201126.404121.129
us-gaap:NetIncomeLoss ▆█▆█▆▇▆▇▁▇▅▆▅▆266.4368.023273.803348.14254.112336.633251.9320.76433.334310.558233.2291.26244.647271.426
us-gaap:NetIncomeLossAttributableToNoncontrollingInterest ██████████▁███1.881.881.881.881.881.881.881.881.881.881.8611.881.881.88
us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic ▆█▆█▆▇▆▇▁▇▅▆▅▆264.52366.143271.923346.26252.232334.753250.0318.88431.454308.7231.3289.4242.767269.546
us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted 264.5NANANA252.2NANANANANANANANANA
us-gaap:NonoperatingIncomeExpense ▇▅▃▄▄▃▄▃▇▄▃▁█▅46.61934.20125.02529.21830.24324.10428.95926.96845.86631.027.716.71850.14933.8
us-gaap:OperatingExpenses ▃█▄▄▂▄▂▃▃▅▃▄▁▄1670.9332240.2721779.2051782.4121519.4731834.6061614.8211666.5591733.5071921.0921634.9351805.4041462.5021845.43
us-gaap:OperatingIncomeLoss ▆█▆█▆▇▆▇▁▇▅▆▅▆451.605585.568454.728561.23433.655539.12435.6509.238150.988494.7400.0466.021391.354442.532
us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax ▅▄▄█▄▁▅▄▂▃0.4450.4070.3780.6020.3870.2290.4480.3670.2620.316NANANANA
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▇▇▁▇▇▇▂▇█▇▆▇▇█0.8811.188-16.0142.1610.5531.948-13.0421.6244.1632.2-0.4181.4062.1423.273
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax ▃█▃▅▂▄▂▃▁▅▂▅▁▄2142.92771.72172.72352.11947.22294.42015.92168.41868.22397.32013.82321.11860.62277.1
us-gaap:Revenues ▃█▄▅▂▅▂▃▁▅▂▄▁▄2122.5382825.842233.9332343.6421953.1282373.7262050.42175.7971884.4952415.7922034.92271.4251853.92288.0
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:Assets ██▇▅▄▄▄▃▂▂▂▁▁▁47234.6446518.21546099.59843507.34542038.71841648.98641123.91539725.39438995.90638941.00738241.25637515.737244.337039.983
us-gaap:LiabilitiesAndStockholdersEquity ██▇▅▄▄▄▃▂▂▂▁▁▁47234.6446518.21546099.59843507.34542038.71841648.98641123.91539725.39438995.90638941.00738241.25637515.66937244.34437039.983
us-gaap:StockholdersEquity ██▇▇▇▆▄▃▃▂▂▂▁▁14311.88914233.4214063.56613980.01713805.25813209.95612629.99412121.61411954.59311637.43411486.81711408.77811273.22311183.714
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:AssetsCurrent █▇▇█▃▄▃▂▁▂▂▁▂▅3268.8393146.8793130.1433220.4132405.4132562.672414.5392220.9052131.6972300.8642292.2242153.3712277.592771.436
us-gaap:Cash █▁▄217.39734.112106.599NA64.8947.42515.43222.68820.57835.1108.06859.164.154303.81
us-gaap:CashAndCashEquivalentsAtCarryingValue NANANA729.993NANA15.432NANANANANANANA
 us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity es:NstarElectricCompanyNANANA0.087NANA0.052NANANANANANANA
 us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNHNANANA0.767NANA0.413NANANANANANANA
 us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity es:TheConnecticutLightAndPowerCompanyNANANA8.173NANANANANANANANANANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▄▂▃█▂▁▁▁▂▁▂▁▁▃368.011175.604264.95829.003176.92133.689117.063151.88167.163108.372209.324134.6121.85362.615
us-gaap:AccountsReceivableNetCurrent ▇█▆▄▂▂▂▂▁▅▂▄▁▄1224.0921290.21195.9251113.495996.291018.941989.383993.396964.3141140.348994.0551091.589967.591086.282
us-gaap:InventoryRawMaterialsAndSupplies ▂█▆▃▁▇▄▃▁▆▄▂▁187.692308.093265.599214.3176.138286.498235.471204.012174.124277.104238.042192.508171.601NA
us-gaap:OtherAssetsCurrent ▆▅▅▅▄▆█▇▇▃▆▄▁▄264.451238.727252.439243.781191.57269.457342.135312.253302.496181.724260.995203.434107.379210.534
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:Goodwill ██▇▁▄▄▄▄▄▄▄▄▄▄4453.6184453.0554445.9884403.6664427.2664427.2664427.2664427.2664427.2664427.2664427.2664427.2664427.2664427.266
us-gaap:OperatingLeaseRightOfUseAsset NANA55.2NANANA49.952.354.656.7NANANANA
 us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity es:NstarElectricCompanyNANA23.6NANANA24.224.224.425.1NANANANA
 us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNHNANA0.3NANANA0.4NANANANANANANA
 us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity es:TheConnecticutLightAndPowerCompanyNANA0.3NANANA0.70.90.60.5NANANANA
us-gaap:OtherAssetsNoncurrent ▅▄▃▃▃▂▂▄▃▁█▅▅▄718.995634.047583.854565.104554.458544.33512.238606.295578.385463.788862.693664.739680.718646.626
us-gaap:EquitySecuritiesFvNi ▃▃▃▂▃▁▅▄▅▆▄██39.939.240.936.841.634.845.743.445.249.644.054.553.6NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:AccountsPayableCurrent ▃▃█▆▂▁▅▁▁▃▄▂▃▂1061.1111060.8671370.6471222.058952.132914.3331147.872892.106903.4311006.7741119.995962.2981010.389984.343
us-gaap:LiabilitiesCurrent ▇█▆▂▁▁▂▂▂▅▃▂▂▃5104.575538.9444915.0123634.073326.0583395.6283605.5633748.913512.1214559.3624112.8823630.2723529.5554096.018
us-gaap:LongTermDebtCurrent ▅█▇▇▄▃▁▅▅▅▅▁▁▇799.8581211.1911053.1861078.186700.96532.44327.411853.066779.289805.519837.319387.31387.2961097.288
us-gaap:OperatingLeaseLiabilityCurrent NANA9.5NANANA8.68.98.89.2NANANANA
 us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity es:NstarElectricCompanyNANA0.7NANANA0.70.60.50.8NANANANA
 us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity es:TheConnecticutLightAndPowerCompanyNANA0.2NANANA0.50.50.20.3NANANANA
us-gaap:OtherLiabilitiesCurrent ▃█▇▆▄▁█▇▃█▇▁▃▆665.424830.399809.214765.443694.252611.706836.834806.839677.341840.587823.006616.662662.964759.112
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:ConsolidatedEntities,us-gaap:DebtInstrument,us-gaap:LongtermDebtType es:TheConnecticutLightAndPowerCompany,srt:ParentCompany,es:A2018SeriesAFirstMortgageBondsDue2048,us-gaap:SeniorNotesNANA650.0NANANA800.0800.0800.0800.0NANANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FairValueByMeasurementBasis es:NstarElectricCompany,us-gaap:FairValueInputsLevel2,us-gaap:EstimateOfFairValueFairValueDisclosure█▇███▆▅▅▄▂▁▁▁▁4208.44063.74294.04285.44240.93901.23659.93695.33599.63107.33024.12990.03019.93071.7
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FairValueByMeasurementBasis es:PublicServiceCompanyOfNewHampshirePSNH,us-gaap:FairValueInputsLevel2,us-gaap:EstimateOfFairValueFairValueDisclosure█▁▇▇▃▁▁1239.01011.01207.01192.11050.3995.81005.7NANANANANANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FairValueByMeasurementBasis es:TheConnecticutLightAndPowerCompany,us-gaap:FairValueInputsLevel2,us-gaap:EstimateOfFairValueFairValueDisclosure█▅▇▅▅▃▄▄▂▂▁▁▁▃5049.84423.94800.94336.74251.63949.44058.04104.43724.93538.03429.23420.43473.33821.9
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByMeasurementBasis es:NstarElectricCompany,us-gaap:CarryingReportedAmountFairValueDisclosure██████▅▅▅▁▁▁▁3688.33643.83643.23642.83642.63642.33342.13341.63341.52945.22944.82944.62944.3NA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByMeasurementBasis es:NstarElectricCompany,us-gaap:EstimateOfFairValueFairValueDisclosureNANA4294.0NANANA3659.9NANANA3024.1NANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByMeasurementBasis es:PublicServiceCompanyOfNewHampshirePSNH,us-gaap:CarryingReportedAmountFairValueDisclosure█▂▆▆▁▁▁1163.7977.31099.11099.0951.6951.7951.6NANANA805.2NANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByMeasurementBasis es:PublicServiceCompanyOfNewHampshirePSNH,us-gaap:EstimateOfFairValueFairValueDisclosureNANA1207.0NANANA1005.7NANANA819.5NANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByMeasurementBasis es:TheConnecticutLightAndPowerCompany,us-gaap:CarryingReportedAmountFairValueDisclosure█▅▅▃▃▃▃▃▁▁▁▁▁4335.63914.73914.83518.13518.13518.13518.13518.53309.53265.83254.03253.63253.3NA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:FairValueByMeasurementBasis es:TheConnecticutLightAndPowerCompany,us-gaap:EstimateOfFairValueFairValueDisclosureNANA4800.9NANANA4058.0NANANA3429.2NANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:LongtermDebtType es:NstarElectricCompany,us-gaap:UnsecuredDebtNANA3393.2NANANA3247.1NANANA2944.8NANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:LongtermDebtType es:PublicServiceCompanyOfNewHampshirePSNH,us-gaap:FirstMortgageNANA817.1NANANA951.6NANANA655.2NANANA
 us-gaap:LongTermDebt dei:LegalEntity,us-gaap:LongtermDebtType es:TheConnecticutLightAndPowerCompany,us-gaap:FirstMortgageNANA3914.8NANANA3518.1NANANA3004.0NANANA
 us-gaap:LongTermDebt us-gaap:ConsolidatedEntities,us-gaap:DebtInstrument,us-gaap:LongtermDebtType srt:ParentCompany,es:EversourceParent3.45SeriesPSeniorNotes,us-gaap:SeniorNotesNANANA650.0NANANANANANANANANANA
 us-gaap:LongTermDebt us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FairValueByMeasurementBasis us-gaap:FairValueInputsLevel2,us-gaap:EstimateOfFairValueFairValueDisclosure█▇█▇▆▄▄▅▄▂▂▁▁▂18364.017198.218420.117943.716329.615177.115170.215479.214639.413519.613154.912517.412501.713376.1
 us-gaap:LongTermDebt us-gaap:FairValueByMeasurementBasis us-gaap:CarryingReportedAmountFairValueDisclosure█▇▇▇▄▄▄▄▃▂▂▁▁16651.215993.916179.115814.514398.714431.014098.214293.213818.513089.813086.112538.812396.6NA
 us-gaap:LongTermDebt us-gaap:FairValueByMeasurementBasis us-gaap:EstimateOfFairValueFairValueDisclosureNANA18420.1NANANA15170.2NANANA13154.9NANANA
 us-gaap:LongTermDebt us-gaap:LongtermDebtType us-gaap:SeniorNotesNANA15125.9NANANA13770.8NANANA12248.7NANANA
us-gaap:LongTermDebtNoncurrent █▆▇▆▄▄▄▄▃▂▁▁▁▁15851.36214782.67215125.87614736.3113697.76213898.58113770.82813440.16513039.1812284.3312248.74312151.53612009.26412015.992
us-gaap:DeferredIncomeTaxLiabilitiesNet █▇▆▅▄▄▃▂▁▁▁4258.9864157.9324095.3393960.6723882.2933816.9883755.7773604.7913549.9223543.0523506.03NANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▆▇█▄▅▅▆▁▂▂▂▃▃▃1455.4791565.7531653.7881163.2291307.9671331.8841370.245821.172955.092939.786962.511013.1821044.3971026.181
us-gaap:OtherLiabilitiesNoncurrent ▃▃▃▂▁▁▁███▇▅▅▅962.166951.75948.506856.285839.791821.195810.5531290.7041264.0611259.41196.3361094.0191069.3911053.765
us-gaap:OperatingLeaseLiabilityNoncurrent NANA45.7NANANA41.343.445.847.5NANANANA
 us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity es:NstarElectricCompanyNANA22.9NANANA23.523.623.924.3NANANANA
 us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity es:TheConnecticutLightAndPowerCompanyNANA0.1NANANA0.20.40.40.2NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA9.0NANANA9.010.110.39.6NANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo dei:LegalEntity es:TheConnecticutLightAndPowerCompanyNANA0.1NANANA0.20.50.20.2NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA6.4NANANA7.48.99.28.7NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA4.5NANANA4.97.47.57.3NANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour dei:LegalEntity es:NstarElectricCompanyNANA1.7NANANA1.61.61.61.6NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive NANA3.4NANANA2.84.94.94.8NANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive dei:LegalEntity es:NstarElectricCompanyNANA1.7NANANA1.71.61.61.6NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA36.2NANANA28.9NANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive dei:LegalEntity es:NstarElectricCompanyNANA27.0NANANA28.7NANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNHNANA0.1NANANA0.2NANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:StockholdersEquity ██▇▇▇▆▄▃▃▂▂▂▁▁14311.88914233.4214063.56613980.01713805.25813209.95612629.99412121.61411954.59311637.43411486.81711408.77811273.22311183.714
 us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss▆▅███▇▆▇▆▄▂▁▁▂0.60.41.11.01.10.90.70.80.60.2-0.5-0.7-0.6-0.4
us-gaap:CommonStockValue █████▆▅▃▃▁▁▁▁▁1789.0921789.0921789.0921789.0921789.0921759.0921729.2921699.2921699.2921669.3921669.3921669.3921669.3921669.392
us-gaap:AdditionalPaidInCapital █████▆▄▃▃▁▁▁▁▁8032.9598016.1188015.6637996.9767979.1467479.6897087.7686675.8896659.0096242.0896241.2226234.0446229.2476224.62
us-gaap:RetainedEarningsAccumulatedDeficit ██▇▆▅▅▄▄▃▄▃▂▁▁4830.0584772.4314613.2014535.864384.0934322.8254177.0484100.223954.4924092.8953953.9743882.6953753.3433670.603
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▂▁▁▆▅▅▄██▆▆▆▅▅-74.342-75.223-76.411-60.397-62.558-63.111-65.059-52.017-53.641-57.804-60.0-59.582-60.988-63.13
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity es:NstarElectricCompany██▇█▇▇▇▃▃▂▂▂▁▁0.5110.370.3090.3550.290.2220.155-1.035-1.147-1.261-1.378-1.498-1.608-1.717
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH█▇▆▅▃▂▁-0.076-0.358-0.613-0.884-1.144-1.429-1.707NANANA-2.851NANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity es:TheConnecticutLightAndPowerCompany▁▁▅▆▇▇▇██▇▅▅▇▆0.2730.270.3020.3070.3180.3150.3160.3250.3260.3180.3010.3060.3180.309
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities srt:ParentCompanyNANA-76.411NANANA-65.059NANANA-60.0NANANA
us-gaap:TreasuryStockValue ▁▁▃▃▄▄▅▆▆▇████265.878268.998277.979281.514284.515288.539299.055301.77304.559309.138317.771317.771317.771317.771
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▄▄▁▅▆▄▅▆▅▄▄█▆▁396.029411.416186.363490.834585.069420.306514.727570.263496.587428.0376.316709.527520.421177.714
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▁▇▇▇▇▆▇▆▇█▇█-793.459-704.517-2119.561-619.212-672.892-717.61-822.439-858.15-671.463-922.236-684.918-558.418-667.426-479.719
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity es:NstarElectricCompany▄▄▁▅▅▁▃▄▄▄▆▇█▆-210.549-215.461-251.94-207.396-199.977-247.528-225.158-217.617-210.007-208.523-186.781-182.461-163.776-192.69
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH█▇▂▅▅▃▁▆▇█-65.845-68.141-94.674-77.941-80.421-88.568-99.843-76.079-67.789-64.259NANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity es:TheConnecticutLightAndPowerCompany█▇▅▇█▆▆▄▁█▇▇▃▇-195.292-197.874-224.206-202.165-194.729-212.3-218.175-233.082-276.197-189.364-203.421-202.939-255.497-202.07
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▃█▅▂▃▃▃▃▃▃▁▁▄589.837203.7551369.145780.461131.054313.93272.895272.604233.667393.284383.321-138.354-93.76578.73
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect █▁192.407-89.346NANA43.23116.626NANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:DeferredIncomeTaxExpenseBenefit ▆▅▇▆▅▅█▅▄▄▇▁▆▇78.47341.917100.35970.24542.34944.201136.32536.95218.4518.085104.398-91.48173.40288.481
us-gaap:DepreciationDepletionAndAmortization ▃█▅▄▂▃▁▄▂▃▃▄▁▂280.2378.7307.2302.0263.9286.0240.2296.5258.0285.9285.8301.4235.3249.5
us-gaap:IncreaseDecreaseInAccountsPayable ▂▁█▅▃▂▇▄▂▄▅▄▄▃-103.945-181.725243.60148.217-41.885-127.366172.221-1.278-142.521-13.55650.5077.468-18.488-61.571
 us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity es:NstarElectricCompany▂▂█▄▄▂▅▆▁▃▆▄▁▆-43.125-45.60482.873-7.4193.581-53.46224.59735.07-64.217-18.10950.3184.016-60.36443.17
 us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH▃▂█▁▆▂▆▃▃▅-8.295-21.02556.658-37.60726.283-18.06424.381-10.941-12.92111.762NANANANA
 us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity es:TheConnecticutLightAndPowerCompany▁▅▄▆▄▄█▅▂▇▂▅▄▄-97.13117.124-15.05247.598-22.276-27.29893.743.161-69.9375.373-61.62115.502-2.397-28.408
us-gaap:IncreaseDecreaseInInventories ▁█▇▇▁██▇▂██▇▂▇-120.40142.49436.50638.23-110.35951.02742.10429.888-102.98139.06345.53320.907-92.56526.956
 us-gaap:IncreaseDecreaseInInventories dei:LegalEntity es:NstarElectricCompany▁█▇▇▁█▇▇▂██▆▂▇-112.25452.99837.54325.89-108.04954.4533.89125.655-95.70846.0247.84115.902-82.48537.427
 us-gaap:IncreaseDecreaseInInventories dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH▃▅▅▆▃▆█▅▁▅-5.7922.2961.5712.513-5.7383.52611.6430.68-14.081-0.144NANANANA
us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet █▆▂▄▅▇▁▃▇▇▁▃▅▅103.48242.386-71.442-10.55429.63761.95-93.53-34.9769.86170.242-93.084-36.37127.77323.456
us-gaap:NetCashProvidedByUsedInOperatingActivities ▄▄▁▅▆▄▅▆▅▄▄█▆▁396.029411.416186.363490.834585.069420.306514.727570.263496.587428.0376.316709.527520.421177.714
us-gaap:NetIncomeLoss ▆█▆█▆▇▆▇▁▇▅▆▅▆266.4368.023273.803348.14254.112336.633251.9320.76433.334310.558233.2291.26244.647271.426
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▁▇▇▇▇▆▇▆▇█▇█-793.459-704.517-2119.561-619.212-672.892-717.61-822.439-858.15-671.463-922.236-684.918-558.418-667.426-479.719
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity es:NstarElectricCompany▄▄▁▅▅▁▃▄▄▄▆▇█▆-210.549-215.461-251.94-207.396-199.977-247.528-225.158-217.617-210.007-208.523-186.781-182.461-163.776-192.69
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity es:PublicServiceCompanyOfNewHampshirePSNH█▇▂▅▅▃▁▆▇█-65.845-68.141-94.674-77.941-80.421-88.568-99.843-76.079-67.789-64.259NANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity es:TheConnecticutLightAndPowerCompany█▇▅▇█▆▆▄▁█▇▇▃▇-195.292-197.874-224.206-202.165-194.729-212.3-218.175-233.082-276.197-189.364-203.421-202.939-255.497-202.07
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▅▃█▄▃▅▆▅▄▃▂▂▂▁734.24688.983841.432701.366674.678725.52782.452751.284703.053674.7638.3633.422644.344607.334
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▃█▅▂▃▃▃▃▃▃▁▁▄589.837203.7551369.145780.461131.054313.93272.895272.604233.667393.284383.321-138.354-93.76578.73
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▇▃▃█▂▅▁▃▆▁▅▂▁▇1175.0350.0400.01420.0190.0750.045.0475.01000.00.0900.0150.00.01150.0
us-gaap:RepaymentsOfLongTermDebt ▅▇▁▁▁▃▆▁▁▃▃▁█▂450.0572.025.031.7850.203220.253550.2230.4180.222250.215189.4750.434710.203150.218
us-gaap:PaymentsOfDividendsCommonStock ██▆▆▆▅▃▄▁▃▂▂▂▂201.198201.013189.01188.838185.209181.608167.668172.225153.589169.757160.028160.027160.028160.027
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1789178917891789178917591729169916991669166916691669166916691669166916691669166916691669166916691669166816661666166616661665166516641664166216621662981980980979978
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.83.83.94.14.34.24.24.34.44.34.44.44.54.54.65.05.15.25.25.45.45.45.55.65.65.65.66.06.05.96.05.95.95.95.96.06.06.16.36.76.86.8

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-312018-12-312017-12-31
Value1789172916691669
Percentage of CommonStockValue100.0100.0100.0100.0
Percentage of Assets3.94.24.44.6
Percentage of Assets srt:ParentCompany8.59.610.010.7

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value344344343338332326320318317317317317317318318318318318318318317317316316315316315301178177177177177176
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value343343343337331324319317317317317317317317317317317317317317316315315315315315314301178177177177176176
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-312011-09-302010-12-312010-09-30
Value0.771.070.791.010.751.010.770.980.10.970.730.910.760.850.750.820.730.820.720.830.640.770.570.740.650.80.70.740.40.750.560.660.540.720.570.660.150.630.510.730.57
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-312011-09-302010-12-312010-09-30
Value0.771.060.791.010.751.010.760.980.10.970.730.910.760.850.750.820.730.820.720.830.640.770.570.740.650.80.690.740.40.740.560.660.540.720.570.660.150.640.510.730.57
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value265367255348252336236320353102302902442722342592292622292652032451882342072541872351302371982111722301662094610197807211612610172
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.413.30.014.813.014.70.014.81.913.00.012.513.212.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity

es:NstarElectricCompany


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value11193811659710094155899477140887712310877665211768546011881836911560
Percentage of ComprehensiveIncomeNetOfTax41.825.631.847.638.629.839.948.4252.330.333.648.435.928.352.541.633.625.223.044.233.522.232.250.639.432.737.149.046.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.23.40.07.05.04.40.07.24.83.90.06.14.73.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value34442947313933412733
Percentage of ComprehensiveIncomeNetOfTax13.212.211.413.612.611.814.312.876.210.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.60.02.01.61.70.01.91.51.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value115981011201171188311110411079100999899969190778683877180786987833779
Percentage of ComprehensiveIncomeNetOfTax43.526.839.834.546.435.335.434.8294.335.534.334.540.736.142.237.039.834.433.932.740.835.537.834.237.927.246.535.628.833.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.43.50.05.16.05.20.05.25.64.60.04.35.44.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01879000.01880000.01879000.0-13158000.01879000.01880000.01879000.01879000.01879000.02043000.01879000.01879000.01880000.01880000.01493000.01520000.01500000.01400000.01429000.01958000.01400000.01400000.0
Percentage of ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations Before Income Taxes Domestic

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value3524823444563294283304006439330135731535537041536941935742333039230338133240834536320737928032026835025232672156127141123179180143112
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax16.517.40.019.416.918.70.018.53.416.40.015.416.915.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic dei:LegalEntity

es:NstarElectricCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value144120105215126127118200116121114192120105203177126108861921138810119513613911419210097
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic41.025.130.847.338.429.835.950.1181.830.737.853.838.329.655.042.934.225.924.145.534.222.633.351.240.934.233.153.048.625.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.84.40.09.26.55.60.09.36.25.00.08.36.54.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value43562363425044523542
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic12.311.76.713.912.811.713.513.155.210.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.02.00.02.72.22.20.02.41.91.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value15313114815815014911915513213910614213112612614814414313014313213512012612110712411357124
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic43.527.343.034.845.835.036.138.8206.835.535.239.841.735.734.135.839.134.336.533.940.034.639.833.236.626.336.031.427.932.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.24.70.06.77.76.50.07.27.15.80.06.17.15.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value861137010875917980308368667083130152137157126156125146119144123153122126771411011099512075117265513494463494139
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.04.10.04.63.94.00.03.71.63.50.02.93.83.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity

es:NstarElectricCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value332624502927254526273651322780694942337544344077545645764039
Percentage of IncomeTaxExpenseBenefit39.223.734.746.338.529.632.357.287.332.453.577.946.333.461.745.735.726.926.248.235.823.334.153.544.036.637.060.852.027.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.00.02.11.51.20.02.11.41.10.02.21.81.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value8.68811-5.84716101011118.5689.537
Percentage of IncomeTaxExpenseBenefit10.110.1-8.315.113.911.613.914.827.811.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.40.40.00.70.50.50.00.50.50.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value383246383331354327292741312827525353525749484946433837302045
Percentage of IncomeTaxExpenseBenefit44.028.965.535.744.534.045.254.790.435.339.563.145.133.920.834.438.834.041.736.539.533.441.532.335.024.930.623.726.232.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.81.20.01.61.71.40.02.01.51.20.01.81.71.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Expense

us-gaap:InterestExpense

us-gaap:InterestExpense


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value14513713513413413413313513213112612512612110210810710310299100989292929489899289888786768490896665636258366567
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.85.00.05.76.95.90.06.27.15.50.05.46.85.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestExpense dei:LegalEntity

es:NstarElectricCompany


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value373235313231282928272426272635242322212120201818172018172021
Percentage of InterestExpense25.623.426.223.124.523.021.521.721.321.219.421.521.621.835.022.521.821.321.321.120.121.319.520.519.321.620.919.322.423.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.20.01.31.71.40.01.41.51.20.01.21.51.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value13141414141416161314
Percentage of InterestExpense9.510.610.411.110.910.712.012.110.510.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.60.50.00.60.80.60.00.80.70.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value423838383837393936353837383636363534353635363636363636383734
Percentage of InterestExpense29.328.328.528.628.828.129.329.227.927.230.630.030.630.435.633.432.933.834.736.135.837.239.239.739.238.641.143.240.538.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.01.40.01.62.01.70.01.82.01.50.01.62.11.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestExpense dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:VariableInterestEntityPrimaryBeneficiary, es:RateReductionBonds


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value4.64.74.84.95.05.05.25.25.35.4
Percentage of InterestExpense3.23.43.53.73.73.73.93.84.04.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.20.00.20.30.20.00.20.30.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:VariableInterestEntityPrimaryBeneficiary es:RateReductionBonds0.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestExpense us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4141423837424041444434303231
Percentage of InterestExpense28.730.231.028.928.031.730.030.833.533.627.424.425.626.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.01.50.01.61.91.90.01.92.41.80.01.31.71.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment12.712.10.012.013.214.50.016.217.717.10.013.613.613.8

us-gaap:IntersegmentElimination


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-12.8-11.6-10.7-7.1-8.8-11.8-11.2-13.9-13.6-12.6-9.1-7.8-8.0-7.4-4.8-4.4-3.5-3.2-2.1-1.3-1.5-2.0-1.2-1.2
Percentage of InterestExpense-8.8-8.4-7.9-5.3-6.6-8.8-8.4-10.3-10.2-9.6-7.2-6.2-6.3-6.1-4.7-4.0-3.3-3.1-2.1-1.3-1.5-2.0-1.3-1.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.6-0.40.0-0.3-0.5-0.50.0-0.6-0.7-0.50.0-0.3-0.4-0.30.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination1.91.80.01.11.52.10.02.52.82.40.01.51.61.50.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6153555354535353504950525247
Percentage of InterestExpense42.038.740.839.840.439.439.839.338.337.440.341.941.239.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.91.90.02.32.82.30.02.52.72.10.02.32.82.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution3.62.80.02.63.43.00.02.83.32.70.02.53.42.7

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3232333132303133303030303029
Percentage of InterestExpense22.423.724.423.223.922.723.424.823.023.224.424.223.724.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.51.20.01.31.61.30.01.51.61.30.01.31.61.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission7.88.20.06.78.39.00.09.110.79.30.08.29.69.4

us-gaap:OperatingSegments, es:EversourceWater


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.17.97.88.08.48.78.48.98.68.68.88.58.68.4
Percentage of InterestExpense5.65.75.86.06.36.56.36.66.56.57.06.86.86.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.40.30.00.30.40.40.00.40.50.40.00.40.50.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value14137.9101011121111111011111110101010101010109.79.2
Percentage of InterestExpense10.010.15.87.58.08.59.08.79.08.98.29.09.09.210.69.910.210.310.310.210.310.310.59.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.70.50.00.40.50.50.00.50.60.50.00.50.60.50.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution4.61.80.08.94.92.70.010.65.72.60.010.35.52.60.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value266368273348254336251320333102332912442712392622322612312672052461832372092552232361292371792111732291762094610011491781151311017387
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.413.30.014.813.114.70.014.81.813.00.012.513.111.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value110938116597100931548994771408777701087766521176854601188183691156058
Percentage of NetIncomeLoss41.625.529.747.638.429.837.148.3269.230.333.248.335.928.429.441.233.325.322.843.933.222.132.849.939.132.831.048.946.524.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.23.40.07.05.04.40.07.14.83.90.06.14.73.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3444284731393340263214402535
Percentage of NetIncomeLoss13.012.110.613.512.411.813.312.880.710.66.114.010.512.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.60.02.01.61.70.01.91.41.40.01.81.41.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value115981011201171188311110411079100999899969190778682877180786987833779
Percentage of NetIncomeLoss43.426.737.234.546.135.333.334.8314.435.633.934.440.836.341.436.739.234.533.732.440.335.438.833.737.627.139.035.528.933.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.43.60.05.16.05.20.05.25.64.60.04.35.44.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity, us-gaap:StatementEquityComponents

es:NstarElectricCompany, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value110931659710015489941408777
Percentage of NetIncomeLoss41.625.547.638.429.848.3269.230.348.335.928.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.23.47.05.04.47.14.83.96.14.73.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value3444473139402632
Percentage of NetIncomeLoss13.012.113.512.411.812.780.610.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.62.01.61.71.91.41.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value115981201171181111041101009998
Percentage of NetIncomeLoss43.426.734.546.135.334.8314.435.634.440.836.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.43.65.16.05.25.25.64.64.35.44.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value26636834825433632033310291244271
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.413.314.813.114.714.81.813.012.513.111.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Attributable To Noncontrolling Interest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01861000.01880000.01880000.01880000.01880000.01880000.01880000.01880000.01861000.01900000.01880000.01880000.01880000.01879000.01880000.01879000.01880000.01879000.01880000.01879000.01879000.01879000.02043000.01879000.01879000.01880000.01880000.01493000.01480000.01470000.01441000.01429000.01954000.01411000.01402000.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value26436627134625233425031831308231289242269237260230259229265203244181235207253221234127235177209171228174207449911389771141291007186
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.313.20.014.713.014.60.014.71.712.90.012.513.011.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value282394237381285442308435-145.6407298271288346
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic106.9107.987.5110.1113.1132.1123.4136.5-462.9132.0129.193.7119.0128.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax13.214.20.016.214.719.30.020.1-7.817.00.011.715.515.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment85.7115.10.0118.3100.6150.10.0168.6-58.1157.90.0120.7121.9149.8

us-gaap:IntersegmentElimination


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-290.4-408.6-245.9-375.1-291.4-450.8-314.2-421.5152-414.5-288.6-270.0-272.2-347.4-263.9-258.2-241.1-321.8-229.5-254.7-220.4-303.3-201.7-240.8
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic-109.8-111.6-90.4-108.3-115.5-134.7-125.7-132.2486.1-134.3-124.8-93.3-112.1-128.9-111.2-99.2-104.5-124.0-100.1-96.0-108.2-124.2-110.9-102.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-13.6-14.70.0-15.9-15.0-19.60.0-19.48.2-17.30.0-11.6-14.6-15.30.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination44.163.10.056.048.679.90.076.9-31.879.70.052.254.772.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value12193932051151309019710512076173101104
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic46.025.534.359.345.638.936.261.9335.138.932.960.141.738.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.73.40.08.75.95.70.09.15.65.00.07.55.44.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution7.25.00.010.07.27.40.010.36.86.60.08.46.56.0

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value137135120125129126118107-87.411897109112107
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic52.037.044.436.351.337.947.233.7-277.938.342.237.846.439.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.44.90.05.36.75.50.05.0-4.74.90.04.76.14.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission32.734.00.027.233.537.30.029.2-30.736.00.029.835.933.9

us-gaap:OperatingSegments, es:EversourceWater


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.93.65.623102.18.6178.00.94.6177.21.5
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic3.41.02.16.74.10.63.45.525.40.32.06.13.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.40.10.01.00.50.10.00.80.40.00.00.80.40.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value4.114760-14.03.38438-17.1-1.87643-12.65.05725-6.24.55025-7.08.05014-3.7
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic1.540.322.2-4.01.325.215.4-5.4-5.724.818.6-4.42.121.410.7-2.42.019.611.3-2.63.920.88.2-1.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.25.30.0-0.60.23.70.0-0.8-0.13.20.0-0.50.32.50.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution1.319.50.0-12.31.520.30.0-15.5-0.916.70.0-11.52.413.60.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Diluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted


Net
Period End2021-06-302020-06-30
Value264252
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.313.0

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense

us-gaap:NonoperatingIncomeExpense


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value46342529302428264531271650332121211322138.0382.011105.241125.7275.565115.5261.6678.2398.9454.9447.7654.8384.3241.8068.773
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.21.20.01.21.61.10.01.22.51.30.00.72.71.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NonoperatingIncomeExpense dei:LegalEntity

es:NstarElectricCompany


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value21161312131212101011121314126.213.4262.0293.2493.1665.0222.836-0.3341.4570.5132.5330.6021.483.287-0.246-0.031
Percentage of NonoperatingIncomeExpense47.049.255.443.843.450.841.839.823.235.845.081.928.537.328.616.29.423.914.236.835.3-16.614.19.819.610.526.627.7-4.5-1.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.60.00.50.70.50.00.50.60.50.00.60.80.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value4.264.1662.9044.0653.6263.194.5824.6342.9847.022
Percentage of NonoperatingIncomeExpense9.112.211.613.912.013.215.817.26.522.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.20.00.20.20.10.00.20.20.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value9.8794.9084.5015.9178.4591.8985.9674.8312.8533.881.9417.17.16.567.1727.5093.8042.7562.6163.6696.2750.9362.9142.3564.0622.1592.7186.4563.131.072
Percentage of NonoperatingIncomeExpense21.214.418.020.328.07.920.617.96.212.57.042.514.219.433.035.417.720.311.826.978.146.528.145.031.537.748.854.456.664.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.20.00.30.40.10.00.20.20.20.00.30.40.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NonoperatingIncomeExpense dei:LegalEntity, us-gaap:FairValueByAssetClass

es:NstarElectricCompany, es:AFUDCEquity


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6.26.25.75.55.35.05.15.65.14.04.14.23.93.43.52.72.21.9
Percentage of NonoperatingIncomeExpense13.318.122.818.817.520.717.620.811.112.914.825.17.810.116.112.710.214.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.30.20.00.20.30.20.00.30.30.20.00.20.20.10.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany es:AFUDCEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, es:EquityinEarningsLossOfUnconsolidatedAffiliate


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.10.10.10.10.10.20.20.2
Percentage of NonoperatingIncomeExpense0.20.30.30.30.40.70.40.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany es:EquityinEarningsLossOfUnconsolidatedAffiliate0.00.00.00.00.00.00.00.0

es:NstarElectricCompany, es:InvestmentIncomeLoss


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.60.20.7-0.20.0-1.31.1-0.9-0.3-0.3-1.1-0.40.30.60.50.9-0.11.2
Percentage of NonoperatingIncomeExpense1.30.62.8-0.70.0-5.43.8-3.3-0.7-1.0-4.0-2.40.61.82.34.2-0.58.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.0-0.00.0-0.10.0-0.0-0.0-0.00.0-0.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany es:InvestmentIncomeLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, es:NonServiceCostBenefits


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value10107.17.27.17.95.55.65.47.09.29.09.58.44.74.74.85.0
Percentage of NonoperatingIncomeExpense21.929.528.424.623.532.819.020.811.822.633.253.818.924.921.722.222.336.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.40.00.30.40.30.00.30.30.30.00.40.50.40.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany es:NonServiceCostBenefits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, es:Other


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.10.10.10.10.10.40.00.10.10.00.00.00.00.00.00.00.00.0
Percentage of NonoperatingIncomeExpense0.20.30.40.30.31.70.00.40.20.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany es:Other0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, us-gaap:InterestIncome


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value4.80.10.20.10.50.10.20.10.20.20.20.20.20.20.70.60.30.1
Percentage of NonoperatingIncomeExpense10.30.30.80.31.70.40.70.40.40.60.71.20.40.63.22.81.40.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany us-gaap:InterestIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, es:AFUDCEquity


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.30.60.70.91.21.51.31.00.90.2
Percentage of NonoperatingIncomeExpense0.61.82.83.14.06.24.53.72.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.10.10.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH es:AFUDCEquity0.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, es:InvestmentIncomeLoss


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.30.10.00.20.3-0.5-0.3-0.10.4
Percentage of NonoperatingIncomeExpense0.60.30.00.71.0-2.1-1.1-0.21.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.0-0.0-0.0-0.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH es:InvestmentIncomeLoss0.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, es:NonServiceCostBenefits


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value2.72.71.81.81.61.91.41.41.50.5
Percentage of NonoperatingIncomeExpense5.87.97.26.25.37.94.85.23.31.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.10.10.00.10.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH es:NonServiceCostBenefits0.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, es:Other


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value0.10.10.00.00.00.00.00.0
Percentage of NonoperatingIncomeExpense0.20.30.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH es:Other0.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:InterestIncome


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.90.70.41.20.50.31.52.50.75.9
Percentage of NonoperatingIncomeExpense1.92.01.64.11.71.25.29.31.519.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.10.00.00.00.10.00.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:InterestIncome0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, es:AFUDCEquity


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.71.72.43.53.93.93.83.63.22.62.83.33.32.83.93.32.92.0
Percentage of NonoperatingIncomeExpense3.65.09.612.012.916.213.113.37.08.410.119.76.68.318.015.613.514.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.20.20.00.20.20.10.00.10.20.10.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany es:AFUDCEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, es:InvestmentIncomeLoss


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.20.41.32.2-3.41.4-0.8-0.11.7-3.90.70.4-0.12.13.1-0.4-0.3
Percentage of NonoperatingIncomeExpense2.61.24.47.3-14.14.8-3.0-0.25.5-14.14.20.8-0.39.714.6-1.9-2.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.00.10.1-0.10.0-0.0-0.00.10.00.00.0-0.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany es:InvestmentIncomeLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, es:NonServiceCostBenefits


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value4.32.70.80.90.91.10.41.7-0.9-0.62.22.02.43.00.50.40.40.5
Percentage of NonoperatingIncomeExpense9.27.93.23.13.04.61.46.3-2.0-1.97.912.04.88.92.31.91.93.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.10.00.00.00.00.00.1-0.0-0.00.00.10.10.10.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany es:NonServiceCostBenefits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, es:Other


Nonoperating
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.00.00.10.00.00.00.1-0.20.00.20.00.00.00.00.00.0
Percentage of NonoperatingIncomeExpense0.00.00.30.00.00.00.2-0.60.01.20.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.0-0.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany es:Other0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:InterestIncome


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.70.10.20.21.40.30.40.30.50.40.80.91.00.91.11.11.31.1
Percentage of NonoperatingIncomeExpense5.80.30.80.74.61.21.41.11.11.32.95.42.02.75.15.26.08.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.00.00.00.10.00.00.00.00.00.00.00.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany us-gaap:InterestIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NonoperatingIncomeExpense us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value309424387306468497-114.9431251302360
Percentage of NonoperatingIncomeExpense663.21240.01324.51013.51942.01842.9-250.51392.61505.6602.21065.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.415.316.515.720.422.9-6.218.010.816.215.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment93.7123.6120.1108.0158.9192.6-45.8167.3112.1127.4156.0

us-gaap:IntersegmentElimination


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-30
Value-304.8-421.0-383.0-303.7-463.2-545.1139-427.6-278.4-281.8-355.3-262.8-245.5-325.5-255.5-222.6-305.8-242.2
Percentage of NonoperatingIncomeExpense-653.8-1231.0-1310.8-1004.2-1921.7-2021.3303.3-1379.4-1665.3-561.9-1051.2-1239.6-1141.9-2397.4-1873.0-2769.3-15206.4-4621.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-14.2-15.2-16.3-15.6-20.2-25.17.4-17.8-12.0-15.1-15.60.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination46.365.057.250.682.199.4-29.082.253.856.673.60.00.00.00.00.00.00.0

us-gaap:NonoperatingIncomeExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2920161612131218321919
Percentage of NonoperatingIncomeExpense64.160.554.854.251.951.526.658.7192.637.958.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.40.70.70.80.50.60.70.81.41.00.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution1.81.10.81.00.70.70.81.01.61.21.1

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value6.85.56.9105.2618.78.19.09.98.0
Percentage of NonoperatingIncomeExpense14.616.123.635.021.6227.719.026.153.819.723.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.30.20.30.50.22.80.50.30.40.50.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission1.61.41.52.71.516.73.12.52.43.22.5

us-gaap:OperatingSegments, es:EversourceWater


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.91.01.60.00.1-0.20.10.40.7-0.6-0.6
Percentage of NonoperatingIncomeExpense1.92.95.50.00.4-0.70.21.34.2-1.2-1.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.10.00.0-0.00.00.00.0-0.0-0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-30
Value4.63.90.70.41.40.00.70.21.51.62.00.30.10.30.60.1-0.3-0.2
Percentage of NonoperatingIncomeExpense9.911.42.41.35.80.01.50.69.03.25.91.40.52.24.41.2-14.9-3.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.10.00.00.10.00.00.00.10.10.10.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution1.50.50.60.20.30.00.30.01.40.80.50.00.00.00.00.00.00.0

us-gaap:NonoperatingIncomeExpense us-gaap:FairValueByAssetClass

es:AFUDCEquity


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value9.29.210101010101013101112109.7109.28.06.7
Percentage of NonoperatingIncomeExpense19.726.940.835.335.744.036.338.928.635.241.271.821.728.748.843.437.249.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.40.30.00.40.60.50.00.50.70.50.00.50.60.40.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:AFUDCEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:EquityinEarningsLossOfUnconsolidatedAffiliate


Nonoperating
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value4.73.73.95.94.06.1255.0
Percentage of NonoperatingIncomeExpense10.110.813.319.516.622.656.516.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.10.20.30.20.31.40.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:EquityinEarningsLossOfUnconsolidatedAffiliate0.00.00.00.00.00.00.00.0

es:GainLossOnDispositionOfPropertyPlantAndEquipment


Nonoperating
Period End2020-09-30
Value1.5
Percentage of NonoperatingIncomeExpense5.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:GainLossOnDispositionOfPropertyPlantAndEquipment0.0

es:InvestmentIncomeLoss


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.9-0.62.61.01.8-4.33.1-2.8-0.61.2-6.21.8-0.30.73.84.6-1.70.7
Percentage of NonoperatingIncomeExpense4.1-1.810.43.46.0-17.810.7-10.4-1.33.9-22.410.8-0.62.117.521.7-7.95.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.1-0.00.00.00.1-0.20.0-0.1-0.00.10.00.1-0.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:InvestmentIncomeLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NonServiceCostBenefits


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2220101110128.1105.87.4161414157.07.37.58.0
Percentage of NonoperatingIncomeExpense47.458.840.437.635.452.728.037.512.623.958.588.529.145.032.334.434.958.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.70.00.50.50.60.00.50.30.30.00.60.80.70.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NonServiceCostBenefits0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:Other


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.30.30.2-0.30.00.40.00.20.40.00.10.20.10.10.40.00.00.0
Percentage of NonoperatingIncomeExpense0.60.90.8-1.00.01.70.00.70.90.00.41.20.20.31.80.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:Other0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestIncome


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value8.41.51.51.51.00.72.02.91.36.51.9101.93.52.52.31.91.6
Percentage of NonoperatingIncomeExpense18.04.46.05.13.32.96.910.82.821.06.964.63.810.411.510.88.811.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.40.10.00.10.10.00.00.10.10.30.00.50.10.20.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:InterestIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Expenses

us-gaap:OperatingExpenses

us-gaap:OperatingExpenses


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1670224017791782151918341614166617331921163418051462184514441485130715961338152913431567130514631405201514501451138318221417149312851576135214481469885883911869100710081043933
Percentage of OperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax78.080.80.075.878.080.00.076.992.880.10.077.878.681.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingExpenses dei:LegalEntity

es:NstarElectricCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value527600543641514587550659547659586733557651833526436476467571460504428536465607449521439547
Percentage of OperatingExpenses31.626.830.536.033.932.034.139.631.634.335.940.738.135.357.735.433.429.834.937.434.332.232.836.733.230.131.035.931.830.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax24.621.70.027.326.425.60.030.429.327.50.031.629.928.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value225226229209202214212215194226
Percentage of OperatingExpenses13.510.112.911.713.311.713.113.011.211.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.58.20.08.910.49.40.010.010.49.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value643821653803636713635663574677608692531627558597490556467583517563472543512663516549495576
Percentage of OperatingExpenses38.536.736.845.141.938.939.439.833.135.337.238.336.434.038.640.237.534.934.938.238.536.036.237.136.532.935.637.935.831.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax30.029.70.034.132.731.10.030.630.728.30.029.828.627.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value451585454561433539435509150494400466391442450502455509438509423488385469412497430440293467360399350418331412159214184203178227195199178226
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax21.121.10.023.922.323.50.023.58.120.60.020.121.019.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingIncomeLoss dei:LegalEntity

es:NstarElectricCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value160136127234146146135219134137126205133118128199147127104208130109117214151159132206121118
Percentage of OperatingIncomeLoss35.523.328.141.733.827.131.143.188.927.931.544.134.226.928.639.632.425.023.940.930.822.530.545.636.732.130.746.941.325.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.54.90.010.07.56.40.010.17.25.70.08.97.25.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value5266347453615664464937564655
Percentage of OperatingIncomeLoss11.711.47.513.312.211.412.912.730.710.09.312.112.012.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.52.40.03.22.72.70.03.02.52.10.02.42.52.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value18616518219118118515219016617114217216315715517717617616317616217115416115314115914692158
Percentage of OperatingIncomeLoss41.328.340.134.141.834.535.137.4110.534.735.737.041.735.534.535.338.634.637.334.538.335.140.034.337.428.537.033.231.333.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.76.00.08.19.38.10.08.88.97.20.07.48.86.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value15169.326181672-35.0171916111314
Percentage of OperatingIncomeLoss3.52.82.04.84.23.016.6-6.911.73.84.12.53.43.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.70.60.01.10.90.70.0-1.60.90.80.00.50.70.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment4.84.70.08.36.35.50.0-13.67.17.40.05.25.76.1

us-gaap:IntersegmentElimination


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value1.60.80.80.83.50.6-108.71090.20.50.50.61.60.50.40.20.90.50.6-1.20.70.50.50.2
Percentage of OperatingIncomeLoss0.40.10.20.10.80.1-25.021.50.10.10.10.10.40.10.10.00.20.10.1-0.20.20.10.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.00.00.00.20.00.05.10.00.00.00.00.10.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination-0.2-0.10.0-0.1-0.6-0.10.0-20.0-0.0-0.10.0-0.1-0.3-0.10.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value183147151301182198157295168179139259171166
Percentage of OperatingIncomeLoss40.725.333.253.742.036.836.157.9111.736.234.955.643.837.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.65.30.012.89.48.60.013.69.07.50.011.29.27.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution10.97.90.014.611.411.30.015.410.99.80.012.511.19.6

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value214211197198196195241123-60.7180166175171165
Percentage of OperatingIncomeLoss47.636.243.535.345.436.255.424.3-40.236.441.637.743.837.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.07.60.08.410.18.50.05.7-3.27.50.07.69.27.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission51.153.20.042.950.957.50.033.6-21.354.90.047.854.652.2

us-gaap:OperatingSegments, es:EversourceWater


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1510.0114319101327168.712261610.0
Percentage of OperatingIncomeLoss3.51.72.67.74.51.93.15.411.11.83.25.64.32.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.70.40.01.81.00.50.01.30.90.40.01.10.90.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value1919984-8.81311759-12.08.410764-7.3168552-1.5189251-3.8229333-4.0
Percentage of OperatingIncomeLoss4.334.018.5-1.63.221.913.7-2.45.621.716.1-1.64.219.411.6-0.34.018.111.8-0.75.319.18.7-0.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.97.20.0-0.40.75.10.0-0.60.44.50.0-0.30.93.80.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution6.226.30.0-7.76.428.40.0-10.94.023.40.0-6.68.120.20.00.00.00.00.00.00.00.00.00.0

Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value445000.0407000.0378000.0602000.0387000.0229000.0448000.0367000.0262000.0316000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax dei:LegalEntity

es:NstarElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value179000.0109000.0110000.0109000.0109000.0109000.0109000.0109000.0109000.0110000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax40.226.829.118.128.247.624.329.741.634.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value266000.0298000.0269000.0268000.0269000.0269000.0269000.0268000.0269000.0269000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax59.873.271.244.569.5117.560.073.0102.785.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-6000.0-7000.0-6000.0-7000.0-6000.0-7000.0-6000.0-7000.0-7000.0-6000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax-1.3-1.7-1.6-1.2-1.6-3.1-1.3-1.9-2.7-1.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.0-0.00.0-0.0-0.0-0.00.0-0.0-0.0-0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.0

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value0.8811.188-16.0142.1610.5531.948-13.0421.6244.1632.2-0.4181.4062.1423.273-2.788-0.68-0.7943.1410.335-0.253-0.1891.6696.702-1.5130.3811.595-33.8371.3352.8141.71212.0821.4291.956-8.6452.1782.4351.864
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.10.00.10.00.10.20.10.00.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

es:NstarElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.1410.061-0.0460.0650.0680.0671.190.1120.1140.1170.120.110.1090.1060.183-0.004-0.004-0.004-0.146-0.01-0.011-0.010.287-0.002-0.002-0.18
Percentage of OtherComprehensiveIncomeLossNetOfTax16.05.10.33.012.33.4-9.16.92.75.3-28.77.85.13.2-6.60.60.5-0.1-43.64.05.8-0.64.30.1-0.5-11.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.2820.2550.2710.260.2850.2780.2630.2780.2960.307
Percentage of OtherComprehensiveIncomeLossNetOfTax32.021.5-1.712.051.514.3-2.017.17.114.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.003-0.032-0.005-0.0110.003-0.001-0.009-0.0010.0080.017-0.005-0.0120.0090.04-0.0010.0320.1240.1670.1120.1440.1470.120.1590.0130.0680.1150.1150.1040.1180.119
Percentage of OtherComprehensiveIncomeLossNetOfTax0.3-2.70.0-0.50.5-0.10.1-0.10.20.81.2-0.90.41.20.0-4.7-15.65.333.4-56.9-77.87.22.4-0.917.87.2-0.37.84.27.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-0.00.0-0.00.0-0.00.0-0.00.00.00.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity, us-gaap:StatementEquityComponents

es:NstarElectricCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.1410.0610.0650.0680.0670.1120.1140.1170.110.1090.106
Percentage of OtherComprehensiveIncomeLossNetOfTax16.05.13.012.33.46.92.75.37.85.13.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.2820.2550.260.2850.2780.2780.2960.307
Percentage of OtherComprehensiveIncomeLossNetOfTax32.021.512.051.514.317.17.114.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.003-0.032-0.0110.003-0.001-0.0010.0080.017-0.0120.0090.04
Percentage of OtherComprehensiveIncomeLossNetOfTax0.3-2.7-0.50.5-0.1-0.10.20.8-0.90.41.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-0.0-0.00.0-0.0-0.00.00.0-0.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.21.51.7-0.11.61.13.51.21.11.83.00.7-2.31.0-1.7-1.90.94.80.81.11.0-34.41.12.01.021
Percentage of OtherComprehensiveIncomeLossNetOfTax22.7126.378.7-18.182.167.784.154.578.284.091.7-102.9289.731.8671.91005.353.971.6-52.9288.762.7101.782.471.158.598.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.10.1-0.00.10.10.20.10.00.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302017-09-30
Value0.50.40.60.40.20.30.30.30.40.5
Percentage of OtherComprehensiveIncomeLossNetOfTax56.833.727.872.310.318.57.213.628.4-73.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedGainLossNetCashFlowHedgeParent0.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.2-0.7-0.10.20.20.20.40.7-0.1-0.2-0.4-1.90.91.71.01.10.21.3-2.8-1.20.10.1-0.30.30.2-0.1
Percentage of OtherComprehensiveIncomeLossNetOfTax22.7-58.9-4.636.210.312.39.631.8-7.1-9.3-12.2279.4-113.454.1-395.3-582.012.019.4185.1-315.06.3-0.3-22.510.711.7-0.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-0.0-0.00.00.00.00.00.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312015-12-31
Value0.8811.1882.1610.5531.9481.6244.1632.1961.4062.1423.3-2.821-0.70.3626.665
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.099.8100.0100.0100.8101.2102.9108.199.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.10.00.10.10.20.10.10.10.10.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value21422771217223521947229420152168186823972013232118602277
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2122282522332343195323732050217518842415203422711853228818951988176221051776203917672055169119331817251318811892167722901777189216351995168418611628109910681114104712351204124311111339
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax99.0102.0102.899.6100.3103.5101.7100.3100.9100.8101.097.999.6100.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues dei:LegalEntity

es:NstarElectricCompany


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value687737670875660733686878681797712939690770690725584603571780591614546750617766581727561666
Percentage of Revenues32.426.130.037.433.830.933.540.436.233.035.041.437.333.736.436.533.128.732.238.333.529.932.338.834.030.530.938.533.529.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax32.126.630.937.233.932.034.040.536.533.335.440.537.133.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value278293263283255276268280240276254290235267
Percentage of Revenues13.110.411.812.113.111.613.112.912.811.412.512.812.711.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax13.010.612.112.113.112.013.312.912.911.512.712.512.611.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value829987836994817899788853740849751865694784713774666732630760679735626704666804675695587734
Percentage of Revenues39.134.937.442.441.937.938.539.239.335.236.938.137.534.337.739.037.834.835.537.338.535.837.136.436.732.035.936.835.032.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax38.735.638.542.342.039.239.139.439.735.437.337.337.334.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues dei:LegalEntity, us-gaap:ConsolidationItems

es:NstarElectricCompany, srt:ConsolidationEliminations


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-122.2-116.4-116.9-113.5-107.4-106.5-105.9-96.2-99.9-98.5-97.6-100.2-96.5-93.1
Percentage of Revenues-5.8-4.1-5.2-4.8-5.5-4.5-5.2-4.4-5.3-4.1-4.8-4.4-5.2-4.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-5.7-4.2-5.4-4.8-5.5-4.6-5.3-4.4-5.3-4.1-4.8-4.3-5.2-4.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany srt:ConsolidationEliminations0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, srt:ConsolidationEliminations


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-43.6-43.3-40.8-50.1-37.0-37.5-33.6-40.5-33.5-37.1
Percentage of Revenues-2.1-1.5-1.8-2.1-1.9-1.6-1.6-1.9-1.8-1.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.0-1.6-1.9-2.1-1.9-1.6-1.7-1.9-1.8-1.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH srt:ConsolidationEliminations0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, srt:ConsolidationEliminations


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-127.3-124.5-123.3-133.7-116.0-122.2-119.0-131.0-115.4-116.7-116.3-121.5-107.4-109.0
Percentage of Revenues-6.0-4.4-5.5-5.7-5.9-5.1-5.8-6.0-6.1-4.8-5.7-5.3-5.8-4.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-5.9-4.5-5.7-5.7-6.0-5.3-5.9-6.0-6.2-4.9-5.8-5.2-5.8-4.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany srt:ConsolidationEliminations0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value330343335322283294261258250258243224237230
Percentage of Revenues15.512.115.013.814.512.412.711.913.310.712.09.912.810.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax15.412.415.413.714.612.813.011.913.410.812.19.712.710.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:IntersegmentElimination


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-659.8-645.0-639.7-602.6-590.3-591.4-544.8-529.3-539.1-531.1-509.7-483.7-500.4-472.0-272.8-220.5-240.7-252.8-241.6-201.2-229.9-220.6-212.1-198.8
Percentage of Revenues-31.1-22.8-28.6-25.7-30.2-24.9-26.6-24.3-28.6-22.0-25.0-21.3-27.0-20.6-14.4-11.1-13.7-12.0-13.6-9.9-13.0-10.7-12.5-10.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-30.8-23.3-29.4-25.6-30.3-25.8-27.0-24.4-28.9-22.2-25.3-20.8-26.9-20.70.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination100.299.70.090.098.4104.90.096.5112.2102.10.093.5100.697.80.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value16761900165020601616180516491931156118331635202715391754
Percentage of Revenues79.067.273.987.982.776.180.488.882.975.980.489.383.176.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax78.268.676.087.683.078.781.889.183.676.581.287.382.877.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution99.8101.30.0100.1100.9102.40.0100.7100.7100.30.097.799.3100.7

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value411400400389376369351347349340333330317305
Percentage of Revenues19.414.217.916.619.315.617.116.018.614.116.414.617.113.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax19.214.518.416.619.316.117.416.018.714.216.614.217.113.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission97.8100.70.084.497.4108.80.094.4122.7103.80.089.9101.196.3

us-gaap:OperatingSegments, es:EversourceWater


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value5246486455465164534550635344
Percentage of Revenues2.51.62.22.72.82.02.53.02.81.92.52.82.91.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.51.72.22.72.92.02.53.02.91.92.52.72.92.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value31178043811021144828210320746828110920642424810918640323599180342195106
Percentage of Revenues14.727.619.64.710.818.913.84.811.019.413.84.811.118.613.15.510.619.213.34.910.216.711.65.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.628.220.24.710.819.614.04.811.119.614.04.711.118.70.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution98.9103.00.096.697.6108.00.093.899.1102.40.099.2100.499.80.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:WaterDistributionSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value52465546
Percentage of Revenues2.51.62.82.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.51.72.92.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:WaterDistributionSegment95.3104.394.7102.9

us-gaap:OperatingSegments, us-gaap:WaterDistribution


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6455465164534550635344
Percentage of Revenues2.72.82.02.53.02.81.92.52.82.91.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.72.92.02.53.02.91.92.52.72.92.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments us-gaap:WaterDistribution97.194.7102.90.0104.7101.7102.70.0101.9104.1101.8

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value472344651846099435074203841648411233972538995389413824137515372443703936220331633265832355320533108230882307123058030046298792995129777279822779028096277952844428196283282830227757275061597815647147281444214418144721429714229
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets dei:LegalEntity

es:NstarElectricCompany


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value131331302912886123861218012128118881149711253112361107010900107671076710536827880958014797277097663768276037437745474407333
Percentage of Assets27.828.028.028.529.029.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets27.828.028.028.529.029.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets es:NstarElectricCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value46994649466444994484437843504127
Percentage of Assets9.910.010.110.310.710.510.610.8
Percentage of Assets9.910.010.110.310.710.510.610.8
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH100.0100.0100.0100.0100.0100.0100.0100.0

es:TheConnecticutLightAndPowerCompany


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1384513582134551308312577124271218511926116991155411409112781108311146106301044510290101741003599189709966295929494940394169360
Percentage of Assets29.329.229.230.129.929.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets29.329.229.230.129.929.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets es:TheConnecticutLightAndPowerCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidatedEntities

srt:ParentCompany


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-31
Value21005181071673015613
Percentage of Assets45.644.043.743.1
Percentage of Assets45.644.043.743.1
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2166921468220892223021202208602046919137185501893917874
Percentage of Assets45.946.247.951.150.450.149.848.247.648.646.7
Percentage of Assets45.946.247.951.150.450.149.848.247.648.646.7
Percentage of Assets us-gaap:CorporateNonSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IntersegmentElimination


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value-21641.1-20664.5-21492.4-20969.1-20452.0-20284.3-19488.8-18494.1-18004.8-18326.6-17464.9-16717.9-16571.1-16672.3-14430.2-13324.7-13002.4-12926.8-12862.7-12286.8-11781.5
Percentage of Assets-45.8-44.4-46.6-48.2-48.7-48.7-47.4-46.6-46.2-47.1-45.7-44.6-44.5-45.0-39.8-40.2-39.8-40.0-40.1-39.5-38.5
Percentage of Assets-45.8-44.4-46.6-48.2-48.7-48.7-47.4-46.6-46.2-47.1-45.7-44.6-44.5-45.0-39.8-40.2-39.8-40.0-40.1-39.5-38.5
Percentage of Assets us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value259042503324981238642316623135225412199921628215072138919250
Percentage of Assets54.853.854.254.955.155.554.855.455.555.255.953.1
Percentage of Assets54.853.854.254.955.155.554.855.455.555.255.953.1
Percentage of Assets us-gaap:OperatingSegments es:EversourceElectricDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value12289117131169511469112241113710904106661049910533102859401
Percentage of Assets26.025.225.426.426.726.726.526.926.927.026.926.0
Percentage of Assets26.025.225.426.426.726.726.526.926.927.026.926.0
Percentage of Assets us-gaap:OperatingSegments es:EversourceElectricTransmission100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, es:EversourceWater


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value241923912375233223942368235123112290226822532182
Percentage of Assets5.15.15.25.45.75.75.75.85.95.85.96.0
Percentage of Assets5.15.15.25.45.75.75.75.85.95.85.96.0
Percentage of Assets us-gaap:OperatingSegments es:EversourceWater100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, es:NaturalGasDistribution


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value659365766450457945034430434541034031401939043747365636363595343233373332330331493104
Percentage of Assets14.014.114.010.510.710.610.610.310.310.310.210.09.89.89.910.410.210.310.310.110.2
Percentage of Assets14.014.114.010.510.710.610.610.310.310.310.210.09.89.89.910.410.210.310.310.110.2
Percentage of Assets us-gaap:OperatingSegments es:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value472344651846099435074203841648411233972538995389413824137515372443703936220331633265832355320533108230882307123058030046298792995129777279822779028096277952844428196283282830227757275061597815647147281444214472
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity

es:NstarElectricCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value131331302912886123861218012128118881149711253112361107010900107671076710536827880958014797277097663768276037437745474407333
Percentage of LiabilitiesAndStockholdersEquity27.828.028.028.529.029.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets27.828.028.028.529.029.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets es:NstarElectricCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value46994649466444994484437843504127
Percentage of LiabilitiesAndStockholdersEquity9.910.010.110.310.710.510.610.8
Percentage of Assets9.910.010.110.310.710.510.610.8
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH100.0100.0100.0100.0100.0100.0100.0100.0

es:TheConnecticutLightAndPowerCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1384513582134551308312577124271218511926116991155411409112781108311146106301044510290101741003599189709966295929494940394169360
Percentage of LiabilitiesAndStockholdersEquity29.329.229.230.129.929.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets29.329.229.230.129.929.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets es:TheConnecticutLightAndPowerCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilities
Period End2020-12-312019-12-312018-12-312017-12-31
Value21005181071673015613
Percentage of LiabilitiesAndStockholdersEquity45.644.043.743.1
Percentage of Assets45.644.043.743.1
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value14311142331406313980138051320912629121211195411637114861140811273111831108610998108851080410711106371050910438103521029410185101109976989097539723961195179406934592379176906740684012395639153811
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.330.630.532.132.831.730.730.530.729.930.030.430.330.230.633.233.333.433.434.234.034.033.934.334.133.833.535.335.134.634.633.533.433.032.633.133.025.525.626.927.126.3

us-gaap:StockholdersEquity dei:LegalEntity

es:NstarElectricCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value4502440845214325416040634159391537513783373036953549345434462738272326902671259424522573260925982530249824632413
Percentage of StockholdersEquity31.531.032.130.930.130.832.932.331.432.532.532.431.530.931.124.925.024.924.924.423.324.725.225.224.824.724.725.1
Percentage of Assets9.59.59.89.99.99.810.19.99.69.79.89.89.59.39.58.38.38.38.38.37.98.48.58.68.58.38.38.7
Percentage of Assets es:NstarElectricCompany34.333.835.134.934.233.535.034.133.333.733.733.933.032.132.733.133.633.633.533.732.033.534.334.933.933.633.60.0

es:PublicServiceCompanyOfNewHampshirePSNH


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value1571156215421488144014091391115111291316130213501387
Percentage of StockholdersEquity11.011.011.010.610.410.711.09.59.511.311.312.213.0
Percentage of Assets3.33.43.33.43.43.43.42.92.93.43.43.74.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH33.433.633.133.132.132.232.00.00.00.031.60.00.0

es:TheConnecticutLightAndPowerCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value5115507150444794455044344387418041364209419939213822363335873539355035093470338933543322314031192984295629362702
Percentage of StockholdersEquity35.735.635.934.333.033.634.734.534.636.236.634.433.932.532.432.232.632.532.431.931.931.830.330.329.329.229.428.1
Percentage of Assets10.810.910.911.010.810.610.710.510.610.811.010.510.39.89.910.710.910.810.810.910.910.810.310.410.09.99.99.7
Percentage of Assets es:TheConnecticutLightAndPowerCompany36.937.337.536.636.235.736.035.135.436.436.834.834.532.633.733.934.534.534.634.234.534.432.732.931.731.431.40.0

us-gaap:StockholdersEquity dei:LegalEntity, us-gaap:StatementEquityComponents

es:NstarElectricCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.5110.370.3090.3550.290.2220.155-1.035-1.147-1.261-1.378-1.498-1.608-1.717-1.8230.3680.5450.4420.0
Percentage of StockholdersEquity0.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2053199319931813181318131813166316531653163316081603159515021045995994992
Percentage of StockholdersEquity14.414.014.213.013.113.714.413.713.814.214.214.114.214.313.69.89.610.010.3
Percentage of Assets4.34.34.34.24.34.44.44.24.24.24.34.34.34.34.13.33.33.33.6
Percentage of Assets es:NstarElectricCompany us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2447241425272511234622492346225320992131209820881948186019441625161314681420
Percentage of StockholdersEquity17.117.018.018.017.017.018.618.617.618.318.318.317.316.617.515.215.614.714.8
Percentage of Assets5.25.25.55.85.65.45.75.75.45.55.55.65.25.05.45.15.34.95.1
Percentage of Assets es:NstarElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value-0.076-0.358-0.613-0.884-1.144-1.429-1.707-1.97-2.248-2.544-2.851-3.922-5.063
Percentage of StockholdersEquity-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value1088928928903903903903678678678678843843
Percentage of StockholdersEquity7.66.56.66.56.56.87.25.65.75.85.97.67.9
Percentage of Assets2.32.02.02.12.12.22.21.71.71.71.82.32.6
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value483634615586538507490475453641627511549
Percentage of StockholdersEquity3.44.54.44.23.93.83.93.93.85.55.54.65.1
Percentage of Assets1.01.41.31.31.31.21.21.21.21.61.61.41.7
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.2730.270.3020.3070.3180.3150.3160.3250.3260.3180.3010.3060.3180.3090.269-0.053-0.576-0.931-1.387
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2810281028102660253525352535241024102410241022102210211921102110191018041682
Percentage of StockholdersEquity19.619.720.019.018.419.220.119.920.220.721.019.419.619.019.019.718.518.117.5
Percentage of Assets6.06.06.16.16.06.16.26.16.26.26.35.95.95.75.86.66.26.16.1
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value224422002173207219541838179117081664173717271650155114521415129911701072961
Percentage of StockholdersEquity15.715.515.514.814.213.914.214.113.914.915.014.513.813.012.812.111.310.710.0
Percentage of Assets4.84.74.74.84.64.44.44.34.34.54.54.44.23.93.94.13.83.63.5
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Stockholders
Period End2020-12-312019-12-312018-12-312017-12-31
Value14063126291148611086
Percentage of StockholdersEquity100.0100.0100.0100.0
Percentage of Assets30.530.730.030.6
Percentage of Assets srt:ParentCompany67.069.868.771.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Stockholders
Period End2020-12-312019-12-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value-76.1-62.8-55.1-57.2-60.2-58.1-58.8-56.5-57.5-57.3-55.6-54.6-62.3
Percentage of StockholdersEquity-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.6
Percentage of Assets-0.2-0.2-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedges


Stockholders
Period End2020-12-312019-12-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value-1.4-3.0-4.4-5.5-6.2-6.6-7.1-7.7-8.2-8.7-9.2-10.3-12.4
Percentage of StockholdersEquity-0.0-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedges0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Stockholders
Period End2020-12-312019-12-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value1.10.7-0.5-0.40.01.13.02.10.40.4-0.6-1.90.7
Percentage of StockholdersEquity0.00.0-0.0-0.00.00.00.00.00.00.0-0.0-0.00.0
Percentage of Assets0.00.0-0.0-0.00.00.00.00.00.00.0-0.0-0.00.0
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-312013-12-31
Value-74.342-75.223-76.411-60.397-62.558-63.111-65.059-52.017-53.641-57.804-60.0-59.582-60.988-63.1-66.403-63.6-62.9-62.1-65.3-65.6-65.4-66.8-74.0-46.031
Percentage of StockholdersEquity-0.5-0.5-0.5-0.4-0.5-0.5-0.5-0.4-0.4-0.5-0.5-0.5-0.5-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.7-0.5
Percentage of Assets-0.2-0.2-0.2-0.1-0.1-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value8032801680157996797974797087667566596242624162346229622462396250626262356192
Percentage of StockholdersEquity56.156.357.057.257.856.656.155.155.753.654.354.655.355.756.358.360.562.564.4
Percentage of Assets17.017.217.418.419.018.017.216.817.116.016.316.616.716.817.219.520.520.922.3
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1789178917891789178917591729169916991669166916691669166916691669166916661665
Percentage of StockholdersEquity12.512.612.712.813.013.313.714.014.214.314.514.614.814.915.115.616.116.717.3
Percentage of Assets3.83.83.94.14.34.24.24.34.44.34.44.44.54.54.65.25.55.66.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4830477246134535438443224177410039544092395338823753367035613175279724482125
Percentage of StockholdersEquity33.733.532.832.431.832.733.133.833.135.234.434.033.332.832.129.627.024.522.1
Percentage of Assets10.210.310.010.410.410.410.210.310.110.510.310.310.19.99.89.99.18.27.6
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value-265.878-268.998-277.979-281.514-284.515-288.539-299.055-301.77-304.559-309.138-317.771-317.771-317.771-317.771-317.771-317.771-309.977-300.467-326.537
Percentage of StockholdersEquity-1.9-1.9-2.0-2.0-2.1-2.2-2.4-2.5-2.5-2.7-2.8-2.8-2.8-2.8-2.9-3.0-3.0-3.0-3.4
Percentage of Assets-0.6-0.6-0.6-0.6-0.7-0.7-0.7-0.8-0.8-0.8-0.8-0.8-0.9-0.9-0.9-1.0-1.0-1.0-1.2
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value326831463130322024052562241422202131230022922153227727712487240323302511247724142415259026182367244927922692210120682365208720182051215822272138195415231357132713371507
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.96.86.87.45.76.25.95.65.55.96.05.76.17.56.97.27.17.87.77.87.88.48.67.98.29.39.07.57.48.47.57.17.37.67.97.77.19.58.79.09.310.4

us-gaap:AssetsCurrent dei:LegalEntity

es:NstarElectricCompany


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value106911301092907862976855771709873836836804935887765661690707671701816772651746841745
Percentage of AssetsCurrent32.735.934.928.235.938.135.434.733.337.936.538.935.333.835.731.828.427.528.627.829.031.529.527.530.530.127.7
Percentage of Assets2.32.42.42.12.12.32.11.91.82.22.22.22.22.52.52.32.02.12.22.22.32.72.52.22.52.82.5
Percentage of Assets es:NstarElectricCompany8.18.78.57.37.18.17.26.76.37.87.67.77.58.78.49.28.28.68.98.79.110.610.28.810.011.310.2

es:PublicServiceCompanyOfNewHampshirePSNH


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value359342393333348306316357
Percentage of AssetsCurrent11.010.912.610.414.511.913.115.6
Percentage of Assets0.80.70.90.80.80.70.80.9
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH7.67.48.47.47.87.07.38.7

es:TheConnecticutLightAndPowerCompany


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value13461115111210449278867848367597947948047491069754880869912873935882938956920860916897
Percentage of AssetsCurrent41.235.535.532.438.634.632.537.735.634.534.737.332.938.630.336.637.336.335.238.736.636.236.538.935.132.833.3
Percentage of Assets2.92.42.42.42.22.11.92.11.92.02.12.12.02.92.12.72.72.82.73.02.93.13.13.12.93.13.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany9.78.28.38.07.47.16.47.06.56.97.07.16.89.67.18.48.49.08.79.49.19.710.09.79.29.79.6

us-gaap:AssetsCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Assets
Period End2020-12-312019-12-312018-12-312017-12-31
Value1055143610511016
Percentage of AssetsCurrent33.759.545.940.9
Percentage of Assets2.33.52.72.8
Percentage of Assets srt:ParentCompany5.07.96.36.5

Cash

us-gaap:Cash

us-gaap:Cash


Cash
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-312008-12-31
Value217341066447152220351085964303381252445304038502335367138413489435736604573282836.5591615152341882689
Percentage of Cash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.10.20.20.10.00.10.10.10.30.20.20.80.10.40.10.10.10.10.10.20.10.10.10.20.10.10.10.30.20.20.10.20.20.30.11.80.00.10.10.10.20.30.60.00.0

us-gaap:Cash dei:LegalEntity

es:NstarElectricCompany


Cashdei:
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value0.5770.0570.1021.1582.8440.0520.2640.1771.7691.6062.40.19.4711.763894.4752.4483.4946.1543.3913.5043.3462.8092.84817121112428.02113
Percentage of Cash0.30.20.11.86.00.31.20.95.01.54.10.23.14.671.518.25.311.615.48.86.914.07.97.825.233.026.538.147.218.529.9
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.30.00.00.00.00.00.00.00.00.00.10.00.00.00.10.00.0
Percentage of Assets es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.10.01.10.10.00.00.10.00.00.00.00.00.20.20.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Cashdei:
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312018-12-31
Value0.2791.9880.1410.0770.0190.4131.439
Percentage of Cash0.15.80.10.10.02.71.3
Percentage of Assets0.00.00.00.00.00.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Cashdei:
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value1989.256906.9183.7850.09.2862.1917.5871.01.82406.0289.3645.837156.5798.6079.449161.057139.227162.3561610157.2370.001
Percentage of Cash91.327.185.210.78.00.040.910.621.481.21.72.879.115.87.423.733.521.721.524.432.34.437.525.323.76.139.130.817.616.70.0
Percentage of Assets0.40.00.20.00.00.00.00.00.00.20.00.00.60.00.00.00.00.00.00.00.10.00.00.00.10.00.10.00.10.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany1.40.10.70.10.00.00.10.00.10.80.00.02.20.10.10.10.20.10.10.10.20.00.10.10.20.00.00.00.00.00.0

us-gaap:Cash us-gaap:ConsolidatedEntities

srt:ParentCompany


Cashus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value0.4341.4690.5910.5210.0930.067
Percentage of Cash0.49.50.51.40.30.3
Percentage of Assets0.00.00.00.00.00.0
Percentage of Assets srt:ParentCompany0.00.00.00.00.00.0

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2020-09-302019-12-31
Value72915
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0
Percentage of Assets1.70.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity

es:NstarElectricCompany


Cash
Period End2020-09-302019-12-31
Value0.0870.052
Percentage of CashAndCashEquivalentsAtCarryingValue0.00.3
Percentage of Assets0.00.0
Percentage of Assets es:NstarElectricCompany0.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Cash
Period End2020-09-302019-12-31
Value0.7670.413
Percentage of CashAndCashEquivalentsAtCarryingValue0.12.7
Percentage of Assets0.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany


Cash
Period End2020-09-30
Value8.173
Percentage of CashAndCashEquivalentsAtCarryingValue1.1
Percentage of Assets0.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.1

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value368175264829176133117151167108209134121362851717812610667
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.40.61.90.40.30.30.40.40.30.50.40.31.00.20.50.20.40.30.2

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents dei:LegalEntity

es:NstarElectricCompany


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value17171712139.1296.3126.5086.36614141513221410215161512
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents4.99.96.61.57.66.85.44.33.813.87.011.410.86.217.159.820.112.714.518.9
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.00.30.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.10.10.10.10.10.10.10.10.10.10.10.10.10.20.11.20.20.20.20.2

es:PublicServiceCompanyOfNewHampshirePSNH


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value39273922342036243928522.1915.953
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents10.715.914.92.719.715.331.315.823.426.625.22.65.6
Percentage of Assets0.10.10.10.10.10.00.10.10.10.10.10.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.80.60.80.50.80.50.80.00.00.01.30.00.0

es:TheConnecticutLightAndPowerCompany


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value207189917158.7674.971147.09411914.95.6952439.619129.462188.4032.205
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents56.410.437.72.19.06.64.29.44.210.543.83.64.767.211.27.512.015.07.93.2
Percentage of Assets0.40.00.20.00.00.00.00.00.00.00.20.00.00.70.00.00.00.10.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany1.50.10.70.10.10.10.00.10.10.10.80.00.12.20.10.10.10.20.10.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value122412901195111399610189899939641140994109196710869259198338798479638068907759289031131856848807980765784789832792773661485488494470523
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.62.82.62.62.42.42.42.52.52.92.62.92.62.92.62.82.62.72.63.12.62.92.53.13.03.82.93.02.93.52.82.82.82.92.82.82.43.03.13.43.33.6

us-gaap:AccountsReceivableNetCurrent dei:LegalEntity

es:NstarElectricCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value445409403439387375346385346400361457382406341322261264257300254256229303288317234
Percentage of AccountsReceivableNetCurrent36.431.733.739.538.936.935.138.835.935.136.341.939.537.436.935.031.330.130.431.231.528.829.732.831.928.127.4
Percentage of Assets0.90.90.91.00.90.90.81.00.91.00.91.21.01.10.91.00.80.80.81.00.80.80.81.01.01.10.8
Percentage of Assets es:NstarElectricCompany3.43.13.13.53.23.12.93.43.13.63.34.23.53.83.23.93.23.33.23.93.33.33.04.13.94.33.2

es:PublicServiceCompanyOfNewHampshirePSNH


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value1191151191211059999104
Percentage of AccountsReceivableNetCurrent9.79.010.010.910.69.810.110.5
Percentage of Assets0.30.20.30.30.30.20.20.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH2.52.52.62.72.42.32.32.5

es:TheConnecticutLightAndPowerCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value496483459473397389400428415443397466385411370404371349359425370379352425395449355
Percentage of AccountsReceivableNetCurrent40.637.538.442.639.938.240.543.143.138.939.942.839.837.940.143.944.539.842.444.246.042.645.545.943.839.741.5
Percentage of Assets1.11.01.01.10.90.91.01.11.11.11.01.21.01.11.01.21.11.11.11.41.21.21.21.41.31.51.2
Percentage of Assets es:TheConnecticutLightAndPowerCompany3.63.63.43.63.23.13.33.63.63.83.54.13.53.73.53.93.63.43.64.33.83.93.74.54.24.83.8

Inventory Raw Materials And Supplies

us-gaap:InventoryRawMaterialsAndSupplies

us-gaap:InventoryRawMaterialsAndSupplies


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value187308265214176286235204174277238192171223
Percentage of InventoryRawMaterialsAndSupplies100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.70.60.50.40.70.60.50.40.70.60.50.50.6

us-gaap:InventoryRawMaterialsAndSupplies dei:LegalEntity

es:NstarElectricCompany


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-312015-12-312014-12-31
Value7418613396701781249064160114665095627574
Percentage of InventoryRawMaterialsAndSupplies39.860.750.445.040.062.352.744.237.157.848.034.529.442.80.00.00.0
Percentage of Assets0.20.40.30.20.20.40.30.20.20.40.30.20.10.30.20.20.2
Percentage of Assets es:NstarElectricCompany0.61.41.00.80.61.51.00.80.61.41.00.60.50.90.81.01.0

es:PublicServiceCompanyOfNewHampshirePSNH


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value2329262522282437
Percentage of InventoryRawMaterialsAndSupplies12.49.510.111.812.99.910.615.8
Percentage of Assets0.00.10.10.10.10.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.50.60.60.60.50.70.60.9

es:TheConnecticutLightAndPowerCompany


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value515757575249505255524445555348445756525152484344504846
Percentage of InventoryRawMaterialsAndSupplies27.718.621.826.929.617.421.525.631.718.818.723.832.50.021.70.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.20.20.20.20.20.10.10.20.20.2
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.40.40.40.40.40.40.40.40.50.50.40.40.50.50.50.40.60.60.50.50.50.50.40.50.50.50.5

Other Assets Current

us-gaap:OtherAssetsCurrent

us-gaap:OtherAssetsCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value264238252243191269342312302181260203107210138159157182134155106133129117622312261351682922142221741041071129594107130100100
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.50.50.60.50.60.80.80.80.50.70.50.30.60.40.50.50.60.40.50.30.40.40.40.20.80.80.50.61.00.80.80.60.40.40.40.30.60.70.90.70.7

us-gaap:OtherAssetsCurrent dei:LegalEntity

es:NstarElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value24232117331631112124511858422416171714119.5113118.8623.877.88510
Percentage of OtherAssetsCurrent9.310.08.67.217.76.19.13.77.013.619.98.954.120.117.810.311.39.411.17.18.910.48.97.56.23.44.8
Percentage of Assets0.10.10.00.00.10.00.10.00.10.10.10.00.20.10.10.00.10.10.00.00.00.00.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.20.20.20.10.30.10.30.10.20.20.50.20.50.40.20.20.20.20.20.10.10.20.20.10.10.10.1

es:PublicServiceCompanyOfNewHampshirePSNH


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value5.2153.1131012276.2681717
Percentage of OtherAssetsCurrent2.01.34.35.314.52.35.26.7
Percentage of Assets0.00.00.00.00.10.00.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.10.10.20.30.60.10.40.4

es:TheConnecticutLightAndPowerCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value448883633169732423206015205646131452321515493216155137
Percentage of OtherAssetsCurrent16.836.933.325.916.625.921.47.87.711.223.17.619.426.834.08.69.328.724.59.914.937.225.013.823.922.016.7
Percentage of Assets0.10.20.20.10.10.20.20.10.10.10.20.00.10.20.10.00.00.20.10.00.10.20.10.10.10.20.1
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.30.60.60.50.30.60.60.20.20.20.50.10.20.50.40.10.10.50.30.20.20.50.30.20.20.50.4

us-gaap:OtherAssetsCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value19332618
Percentage of OtherAssetsCurrent7.59.810.313.5
Percentage of Assets0.00.10.10.1
Percentage of Assets srt:ParentCompany0.10.20.20.1

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value4453445344454403442744274427442744274427442744274427442744003519351935193500351935193519351935193519351935193519351935193519351935193519351935183518287287287287287
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets9.49.69.610.110.510.610.811.111.411.411.611.811.912.012.110.610.810.910.911.311.411.511.511.711.811.811.812.612.712.512.712.412.512.412.412.712.81.81.82.02.02.0

us-gaap:Goodwill us-gaap:BusinessAcquisition

es:ColumbiaGasOfMassachusettsCMA


Goodwillus-gaap:
Period End2020-10-09
Value42
Percentage of Goodwill0.0
Percentage of Assets0.0
Percentage of Assets es:ColumbiaGasOfMassachusettsCMA0.0

us-gaap:Goodwill us-gaap:StatementBusinessSegments

es:NaturalGasDistribution


Goodwillus-gaap:
Period End2020-12-312019-12-312017-12-312016-12-312015-12-312014-12-31
Value441399400400400400
Percentage of Goodwill9.99.09.111.411.411.4
Percentage of Assets1.01.01.11.21.31.3
Percentage of Assets es:NaturalGasDistribution0.00.00.00.012.913.2

es:WaterDistributionSegment


Goodwillus-gaap:
Period End2020-12-312019-12-31
Value884907
Percentage of Goodwill19.920.5
Percentage of Assets1.92.2
Percentage of Assets es:WaterDistributionSegment0.00.0

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value5549525456
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.1

us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity

es:NstarElectricCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value2324242425
Percentage of OperatingLeaseRightOfUseAsset42.848.546.344.744.3
Percentage of Assets0.10.10.10.10.1
Percentage of Assets es:NstarElectricCompany0.20.20.20.20.2

es:PublicServiceCompanyOfNewHampshirePSNH


Operating
Period End2020-12-312019-12-31
Value0.30.4
Percentage of OperatingLeaseRightOfUseAsset0.50.8
Percentage of Assets0.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value0.30.70.90.60.5
Percentage of OperatingLeaseRightOfUseAsset0.51.41.71.10.9
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value718634583565554544512606578463862664680646605627590556522344319299295324316329349347370504291279286311327300311171172168152179
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.51.41.31.31.31.31.21.51.51.22.31.81.81.71.71.91.81.71.61.11.01.01.01.11.11.11.21.21.31.81.01.01.01.11.21.11.11.11.11.11.11.2

us-gaap:OtherAssetsNoncurrent dei:LegalEntity

es:NstarElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1731611621481401391441491421341091079386847971636011861586260585573
Percentage of OtherAssetsNoncurrent24.225.527.926.225.325.628.224.724.729.012.716.113.713.414.012.712.111.411.634.519.419.521.218.618.617.020.9
Percentage of Assets0.40.30.40.30.30.30.40.40.40.30.30.30.30.20.20.20.20.20.20.40.20.20.20.20.20.20.2
Percentage of Assets es:NstarElectricCompany1.31.21.31.21.21.11.21.31.31.21.01.00.90.80.81.00.90.80.81.50.80.80.80.80.80.81.0

es:PublicServiceCompanyOfNewHampshirePSNH


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value2124233738414327
Percentage of OtherAssetsNoncurrent3.03.94.16.66.97.68.43.2
Percentage of Assets0.00.10.10.10.10.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.50.50.50.80.90.91.00.7

es:TheConnecticutLightAndPowerCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value273258242241248250217229221197199175172171159145138140137131121113111145146171177
Percentage of OtherAssetsNoncurrent38.040.741.642.844.946.042.537.838.442.623.226.425.326.526.323.223.425.226.438.038.137.737.644.746.251.950.7
Percentage of Assets0.60.60.50.60.60.60.50.60.60.50.50.50.50.50.40.40.40.40.40.40.40.40.40.50.50.60.6
Percentage of Assets es:TheConnecticutLightAndPowerCompany2.01.91.81.82.02.01.81.91.91.71.81.61.61.51.51.41.31.41.41.31.31.21.21.51.61.81.9

us-gaap:OtherAssetsNoncurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value90927358
Percentage of OtherAssetsNoncurrent15.518.08.59.6
Percentage of Assets0.20.20.20.2
Percentage of Assets srt:ParentCompany0.40.50.40.4

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi

us-gaap:EquitySecuritiesFvNi


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3939403641344543454944545350
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.1

us-gaap:EquitySecuritiesFvNi dei:LegalEntity

es:CyapcAndYaec


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value207203205189172162182163158166200
Percentage of EquitySecuritiesFvNi519.5518.6501.5514.9414.2465.5400.0377.2350.7335.9454.5
Percentage of Assets0.40.40.40.40.40.40.40.40.40.40.5
Percentage of Assets es:CyapcAndYaec0.00.00.00.00.00.00.00.00.00.00.0

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value106110601370122295291411478929031006111996210109841085794587745884679631646813610598739868608561711742554532633764542600412633476373417
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.22.33.02.82.32.22.82.22.32.62.92.62.72.73.02.41.82.32.82.22.02.12.72.02.02.52.92.22.02.52.71.91.92.22.72.02.22.64.03.22.62.9

us-gaap:AccountsPayableCurrent dei:LegalEntity

es:NstarElectricCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value308275383304262264363304288306384296315329340198151177232194146189228172173233217
Percentage of AccountsPayableCurrent29.026.028.024.927.528.931.734.131.930.534.330.831.333.531.325.025.723.726.328.723.329.328.128.229.031.625.0
Percentage of Assets0.70.60.80.70.60.60.90.80.70.81.00.80.80.90.90.60.50.50.70.60.50.60.70.60.60.80.7
Percentage of Assets es:NstarElectricCompany2.32.13.02.52.22.23.12.62.62.73.52.72.93.13.22.41.92.22.92.51.92.53.02.32.33.13.0

es:PublicServiceCompanyOfNewHampshirePSNH


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value122101132110133103127111
Percentage of AccountsPayableCurrent11.59.59.79.014.011.311.19.9
Percentage of Assets0.30.20.30.30.30.20.30.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH2.62.22.82.43.02.42.92.7

es:TheConnecticutLightAndPowerCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value290369451554310331374280287347324347378346367292229281289228219246267207208230272
Percentage of AccountsPayableCurrent27.434.932.945.432.636.332.631.431.934.629.036.137.535.233.936.839.137.732.733.734.738.132.934.034.931.131.4
Percentage of Assets0.60.81.01.30.70.80.90.70.70.90.80.91.00.91.00.90.70.90.90.70.70.80.90.70.70.80.9
Percentage of Assets es:TheConnecticutLightAndPowerCompany2.12.73.44.22.52.73.12.42.53.02.83.13.43.13.52.82.22.82.92.32.32.62.82.22.22.42.9

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value510455384915363433263395360537483512455941123630352940963589262037853333363826422303259329892971283831113134292928022790327533783081383936433800349019671947153514761345
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets10.811.910.78.47.98.28.89.49.011.710.89.79.511.19.97.911.610.311.48.57.58.49.89.99.510.410.510.510.19.911.811.910.913.612.913.712.712.312.410.410.29.3

us-gaap:LiabilitiesCurrent dei:LegalEntity

es:NstarElectricCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value136816551408125896310581135109610531440126711461160122110256367681120111662369386376610541140953878
Percentage of LiabilitiesCurrent26.829.928.734.629.031.231.529.230.031.630.831.632.929.828.624.320.333.630.723.630.133.325.635.540.230.628.0
Percentage of Assets2.93.63.12.92.32.52.82.82.73.73.33.13.13.32.81.92.43.53.52.02.22.82.53.53.83.23.0
Percentage of Assets es:NstarElectricCompany10.412.710.910.27.98.79.69.59.412.811.410.510.811.39.77.79.514.014.08.19.011.210.114.215.312.812.0

es:PublicServiceCompanyOfNewHampshirePSNH


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value350647664602585387352516
Percentage of LiabilitiesCurrent6.911.713.516.617.611.49.812.6
Percentage of Assets0.71.41.41.41.40.90.91.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH7.513.914.313.413.18.88.112.5

es:TheConnecticutLightAndPowerCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value8309578601316108310308769909988349831151103913181092101811077611008104486190793577677711111074
Percentage of LiabilitiesCurrent16.317.317.536.232.630.324.326.428.418.323.931.729.532.230.438.929.322.827.739.537.435.031.326.127.435.734.3
Percentage of Assets1.82.11.93.02.62.52.12.52.62.12.63.12.83.63.03.13.42.43.13.42.83.03.12.62.63.73.6
Percentage of Assets es:TheConnecticutLightAndPowerCompany6.07.16.410.18.68.37.28.38.57.28.610.29.411.810.39.810.87.510.010.58.99.49.88.28.311.811.5

us-gaap:LiabilitiesCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilities
Period End2020-12-312019-12-312018-12-312017-12-31
Value16509691076885
Percentage of LiabilitiesCurrent33.626.926.224.7
Percentage of Assets3.62.42.82.4
Percentage of Assets srt:ParentCompany7.95.46.45.7

Long Term Debt Current

us-gaap:LongTermDebtCurrent

us-gaap:LongTermDebtCurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value7991211105310787005323278537798058373873871097549957148377377337317837822822827824524524539553053360888894776387968326733133433666
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.72.62.32.51.71.30.82.12.02.12.21.01.03.01.52.94.52.42.41.20.61.20.70.80.90.80.80.91.41.91.92.13.23.32.73.22.51.72.12.32.30.5

us-gaap:LongTermDebtCurrent dei:LegalEntity

es:Aquarion


Long
Period End2021-03-31
Value40
Percentage of LongTermDebtCurrent3.3
Percentage of Assets0.1
Percentage of Assets es:Aquarion0.0

es:NstarElectricCompany


Long
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value2502502500.00.0959595950.00.0434004004000.00.02002002002004.74.7
Percentage of LongTermDebtCurrent20.623.723.20.00.029.011.112.211.80.00.04.627.051.751.70.00.052.887.487.471.71.91.9
Percentage of Assets0.50.50.60.00.00.20.20.20.20.00.00.11.21.21.20.00.00.70.70.70.70.00.0
Percentage of Assets es:NstarElectricCompany1.91.92.00.00.00.80.80.80.80.00.00.54.95.05.00.00.02.62.62.72.70.10.1

es:PublicServiceCompanyOfNewHampshirePSNH


Long
Period End2021-03-312020-12-312020-09-302020-06-302019-12-312018-12-31
Value1602822821220.0150
Percentage of LongTermDebtCurrent13.226.826.217.40.017.9
Percentage of Assets0.30.60.60.30.00.4
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH3.46.06.32.70.03.6

us-gaap:LongTermDebtCurrent dei:LegalEntity, us-gaap:LongtermDebtType

es:NstarElectricCompany, us-gaap:UnsecuredDebt


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value250950.00.0400200
Percentage of LongTermDebtCurrent23.729.00.00.051.787.4
Percentage of Assets0.50.20.00.01.20.7
Percentage of Assets es:NstarElectricCompany us-gaap:UnsecuredDebt0.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:FirstMortgage


Long
Period End2020-12-312019-12-312018-12-31
Value2820.0150
Percentage of LongTermDebtCurrent26.80.017.9
Percentage of Assets0.60.00.4
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:FirstMortgage0.00.00.0

us-gaap:LongTermDebtCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Long
Period End2020-12-312019-12-312018-12-312017-12-31
Value4732337832
Percentage of LongTermDebtCurrent45.07.345.25.8
Percentage of Assets1.00.11.00.1
Percentage of Assets srt:ParentCompany2.30.12.30.2

us-gaap:LongTermDebtCurrent us-gaap:LongtermDebtType

us-gaap:LoansPayable


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value49020140110425
Percentage of LongTermDebtCurrent46.561.447.919.03.2
Percentage of Assets1.10.51.00.30.1
Percentage of Assets us-gaap:LoansPayable0.00.00.00.00.0

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value9500000.08600000.08900000.08800000.09200000.0
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity

es:NstarElectricCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value700000.0700000.0600000.0500000.0800000.0
Percentage of OperatingLeaseLiabilityCurrent7.48.16.75.78.7
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value200000.0500000.0500000.0200000.0300000.0
Percentage of OperatingLeaseLiabilityCurrent2.15.85.62.33.3
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value665830809765694611836806677840823616662759738530591639684526472381678563595546828629580713702648650671744678640369176139121167
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.41.81.81.81.71.52.02.01.72.22.21.61.82.02.01.61.82.02.11.71.51.22.21.92.01.82.82.22.12.52.52.32.32.42.62.42.32.31.10.90.81.2

us-gaap:OtherLiabilitiesCurrent dei:LegalEntity

es:NstarElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value49747210455687111261527411361577958485471565858728886116115
Percentage of OtherLiabilitiesCurrent7.59.08.913.78.011.28.514.09.16.29.118.49.37.610.811.18.28.510.410.812.415.410.615.814.621.314.0
Percentage of Assets0.10.20.20.20.10.20.20.30.20.10.20.30.20.20.20.20.10.20.20.20.20.20.20.30.30.40.4
Percentage of Assets es:NstarElectricCompany0.40.60.60.80.50.60.61.00.50.50.71.00.60.50.80.70.60.70.90.70.80.80.91.21.21.61.6

es:PublicServiceCompanyOfNewHampshirePSNH


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value4653383626393244
Percentage of OtherLiabilitiesCurrent7.16.54.84.73.96.53.95.4
Percentage of Assets0.10.10.10.10.10.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH1.01.20.80.80.60.90.81.1

es:TheConnecticutLightAndPowerCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1046310213112615213216914771161152119264127991431271209412211811012497207153
Percentage of OtherLiabilitiesCurrent15.77.712.617.218.324.915.821.021.88.519.624.718.134.817.218.824.420.017.618.026.031.116.322.116.338.018.5
Percentage of Assets0.20.10.20.30.30.40.30.40.40.20.40.40.30.70.40.30.40.40.40.30.40.40.40.40.30.70.5
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.80.50.81.01.01.21.11.41.30.61.41.31.12.41.21.01.41.31.21.01.31.21.21.31.02.21.6

us-gaap:OtherLiabilitiesCurrent dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:RegulatoryAsset

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:VariableInterestEntityPrimaryBeneficiary, es:OtherRegulatoryAssets


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value7.73.18.03.28.33.38.6
Percentage of OtherLiabilitiesCurrent1.20.41.00.41.20.51.0
Percentage of Assets0.00.00.00.00.00.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:VariableInterestEntityPrimaryBeneficiary es:OtherRegulatoryAssets0.00.00.00.00.00.00.0

us-gaap:OtherLiabilitiesCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value103625756
Percentage of OtherLiabilitiesCurrent12.87.57.07.7
Percentage of Assets0.20.20.20.2
Percentage of Assets srt:ParentCompany0.50.30.30.4

Long Term Debt

us-gaap:LongTermDebt dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:LongTermDebt

es:TheConnecticutLightAndPowerCompany, srt:ParentCompany, es:A2018SeriesAFirstMortgageBondsDue2048, us-gaap:SeniorNotes


Long
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value650800800800800
Percentage of LongTermDebt100.0100.0100.0100.0100.0
Percentage of Assets1.41.92.02.12.1
Percentage of Assets es:TheConnecticutLightAndPowerCompany srt:ParentCompany es:A2018SeriesAFirstMortgageBondsDue2048 us-gaap:SeniorNotes0.00.00.00.00.0

us-gaap:LongTermDebt dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis

es:NstarElectricCompany, us-gaap:FairValueInputsLevel2, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value420840634294428542403901365936953599310730242990301930713156259826052202220123382182
Percentage of LongTermDebt0.00.0660.60.00.00.0457.5461.9449.9388.40.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets8.98.79.39.810.19.48.99.39.28.07.98.08.18.38.77.88.06.86.97.57.1
Percentage of Assets es:NstarElectricCompany us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:FairValueInputsLevel2, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value123910111207119210509951005
Percentage of LongTermDebt0.00.0185.70.00.00.0125.7
Percentage of Assets2.62.22.62.72.52.42.4
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:FairValueInputsLevel2, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value504944234800433642513949405841043724353834293420347338213430338832473179304932163031
Percentage of LongTermDebt0.00.0738.60.00.00.0507.2513.0465.6442.20.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets10.79.510.410.010.19.59.910.39.69.19.09.19.310.39.510.29.99.89.510.39.9
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LongTermDebt dei:LegalEntity, us-gaap:FairValueByMeasurementBasis

es:NstarElectricCompany, us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-312015-12-31
Value3688364336433642364236423342334133412945294429442944294320782029
Percentage of LongTermDebt0.00.0560.50.00.00.0417.8417.7417.7368.10.00.00.00.00.00.0
Percentage of Assets7.87.87.98.48.78.78.18.48.67.67.77.87.98.16.56.6
Percentage of Assets es:NstarElectricCompany us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value429436593024315622012182
Percentage of LongTermDebt660.6457.50.00.00.00.0
Percentage of Assets9.38.97.98.76.97.1
Percentage of Assets es:NstarElectricCompany us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value116397710991099951951951805
Percentage of LongTermDebt0.00.0169.10.00.00.0119.00.0
Percentage of Assets2.52.12.42.52.32.32.32.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2020-12-312019-12-312018-12-31
Value12071005819
Percentage of LongTermDebt185.7125.70.0
Percentage of Assets2.62.42.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-312015-12-31
Value4335391439143518351835183518351833093265325432533253305927662763
Percentage of LongTermDebt0.00.0602.30.00.00.0439.8439.8413.7408.20.00.00.00.00.00.0
Percentage of Assets9.28.48.58.18.48.48.68.98.58.48.58.78.78.48.69.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value480040583429343030493031
Percentage of LongTermDebt738.6507.20.00.00.00.0
Percentage of Assets10.49.99.09.59.59.9
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.0

us-gaap:LongTermDebt dei:LegalEntity, us-gaap:LongtermDebtType

es:NstarElectricCompany, us-gaap:UnsecuredDebt


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value339332472944294316781829
Percentage of LongTermDebt522.0405.90.00.00.00.0
Percentage of Assets7.47.97.78.15.26.0
Percentage of Assets es:NstarElectricCompany us-gaap:UnsecuredDebt0.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:FirstMortgage


Long
Period End2020-12-312019-12-312018-12-31
Value817951655
Percentage of LongTermDebt125.7119.00.0
Percentage of Assets1.82.31.7
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:FirstMortgage0.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:FirstMortgage


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value391435183004275925162763
Percentage of LongTermDebt602.3439.80.00.00.00.0
Percentage of Assets8.58.67.97.67.89.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:FirstMortgage0.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

srt:ParentCompany, es:EversourceParent3.45SeriesPSeniorNotes, us-gaap:SeniorNotes


Long
Period End2020-09-30
Value650
Percentage of LongTermDebt0.0
Percentage of Assets1.5
Percentage of Assets srt:ParentCompany es:EversourceParent3.45SeriesPSeniorNotes us-gaap:SeniorNotes0.0

us-gaap:LongTermDebt us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis

us-gaap:FairValueInputsLevel2, us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value1836417198184201794316329151771517015479146391351913154125171250113376128771196810935104289980104549425
Percentage of LongTermDebt0.00.02833.90.00.00.01896.31934.91829.91690.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets38.937.040.041.238.836.436.939.037.534.734.433.433.636.135.636.133.532.231.133.630.8
Percentage of Assets us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-312015-12-31
Value166511599316179158141439814431140981429313818130891308612538123961232596039034
Percentage of LongTermDebt0.00.02489.10.00.00.01762.31786.71727.31636.20.00.00.00.00.00.0
Percentage of Assets35.334.435.136.334.334.634.336.035.433.634.233.433.334.030.029.5
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:EstimateOfFairValueFairValueDisclosure


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value1842015170131541287799809425
Percentage of LongTermDebt2833.91896.30.00.00.00.0
Percentage of Assets40.036.934.435.631.130.8
Percentage of Assets us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:LongtermDebtType

us-gaap:SeniorNotes


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value1512513770122481177588298805
Percentage of LongTermDebt2327.11721.30.00.00.00.0
Percentage of Assets32.833.532.032.527.528.8
Percentage of Assets us-gaap:SeniorNotes0.00.00.00.00.00.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1585114782151251473613697138981377013440130391228412248121511200912015117751046888999267882992359435914488058757868986028606816681478318777674447651701172006732693649774614461443564632
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets33.631.832.833.932.633.433.533.833.431.532.032.432.232.432.531.627.228.627.529.730.629.828.829.129.128.728.929.229.329.628.026.227.124.825.424.325.231.129.531.330.232.0

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value425841574095396038823816375536043549354335063297
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets9.08.98.99.19.29.29.19.19.19.19.29.1

us-gaap:DeferredIncomeTaxLiabilitiesNet dei:LegalEntity

es:NstarElectricCompany


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value150414771459139413991374135713291318130512941275
Percentage of DeferredIncomeTaxLiabilitiesNet35.335.535.635.236.036.036.136.937.136.836.938.7
Percentage of Assets3.23.23.23.23.33.33.33.33.43.43.43.5
Percentage of Assets es:NstarElectricCompany11.511.311.311.311.511.311.411.611.711.611.712.1

es:PublicServiceCompanyOfNewHampshirePSNH


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value546544537525518511506481
Percentage of DeferredIncomeTaxLiabilitiesNet12.813.113.113.313.313.413.513.7
Percentage of Assets1.21.21.21.21.21.21.21.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH11.611.711.511.711.611.711.611.7

es:TheConnecticutLightAndPowerCompany


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value146014381408135012911270124412051192118411661103
Percentage of DeferredIncomeTaxLiabilitiesNet34.334.634.434.133.333.333.133.433.633.433.333.5
Percentage of Assets3.13.13.13.13.13.03.03.03.13.03.13.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany10.610.610.510.310.310.210.210.110.210.310.210.4

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1455156516531163130713311370821955939962101310441026122894610731077114111161294135514071498163616051638787825890896180819562097213020152064124113261050
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.13.43.62.73.13.23.32.12.42.42.52.72.82.83.42.93.33.33.63.64.24.44.65.05.55.45.52.83.03.23.26.46.97.47.57.37.57.88.57.3

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent dei:LegalEntity

es:NstarElectricCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value12715617284969510820295.496146.171178089391119911191194188209211220228235
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent8.710.010.47.27.47.27.92.53.10.61.50.61.77.87.34.210.49.29.88.215.013.914.914.113.414.214.4
Percentage of Assets0.30.30.40.20.20.20.30.10.10.00.00.00.00.20.20.10.30.30.30.30.60.60.70.70.70.80.8
Percentage of Assets es:NstarElectricCompany1.01.21.30.70.80.80.90.20.30.00.10.10.20.70.90.51.41.21.41.22.52.52.82.83.03.13.2

es:PublicServiceCompanyOfNewHampshirePSNH


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value169177184123148152157124
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent11.611.411.210.611.311.511.512.9
Percentage of Assets0.40.40.40.30.40.40.40.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH3.63.84.02.73.33.53.63.0

es:TheConnecticutLightAndPowerCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value364449478325354385391248275279282301306266354297301296300274247267271284286272273
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent25.128.728.928.027.128.928.530.328.829.829.429.829.326.028.931.428.127.526.324.619.119.819.319.017.517.016.7
Percentage of Assets0.81.01.00.70.80.91.00.60.70.70.70.80.80.71.00.90.90.90.90.90.80.90.90.91.00.90.9
Percentage of Assets es:TheConnecticutLightAndPowerCompany2.63.33.62.52.83.13.22.12.42.42.52.72.82.43.32.82.92.93.02.82.52.82.83.03.02.92.9

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:BalanceSheetLocation, us-gaap:RetirementPlanType

es:AccruedPensionSERPandPBOP, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value24252539
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent1.51.92.63.2
Percentage of Assets0.10.10.10.1
Percentage of Assets es:AccruedPensionSERPandPBOP us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.0

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value96295194885683982181012901264125911961094106910531073881860848853875875869871872875870874863882871923897899873967871884414420671696695
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.02.02.12.02.02.02.03.23.23.23.12.92.92.83.02.72.62.62.72.82.82.82.82.92.92.92.93.13.23.13.33.23.23.13.43.13.22.62.74.64.84.8

us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity

es:NstarElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value348338337353347334320325297293263219209197198135130125123125124123120122123126129
Percentage of OtherLiabilitiesNoncurrent36.235.635.641.241.440.739.625.223.523.322.020.019.618.718.515.415.114.814.414.314.314.213.914.014.114.514.8
Percentage of Assets0.70.70.70.80.80.80.80.80.80.80.70.60.60.50.50.40.40.40.40.40.40.40.40.40.40.40.4
Percentage of Assets es:NstarElectricCompany2.72.62.62.92.92.82.72.82.62.62.42.01.91.81.91.61.61.61.51.61.61.61.61.61.71.71.8

es:PublicServiceCompanyOfNewHampshirePSNH


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value3738373937363736
Percentage of OtherLiabilitiesNoncurrent3.94.04.04.64.54.44.63.0
Percentage of Assets0.10.10.10.10.10.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.80.80.80.90.80.80.90.9

es:TheConnecticutLightAndPowerCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value138136133153151149147149153165155130119124128134125123123130131131133143144150148
Percentage of OtherLiabilitiesNoncurrent14.414.314.118.018.018.218.211.612.213.113.011.911.211.811.915.314.614.614.414.915.115.215.316.516.617.317.0
Percentage of Assets0.30.30.30.40.40.40.40.40.40.40.40.30.30.30.40.40.40.40.40.40.40.40.40.50.50.50.5
Percentage of Assets es:TheConnecticutLightAndPowerCompany1.01.01.01.21.21.21.21.31.31.41.41.21.11.11.21.31.21.21.21.31.41.41.41.51.51.61.6

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value4541434547
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.1

us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity

es:NstarElectricCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value2223232324
Percentage of OperatingLeaseLiabilityNoncurrent50.156.954.452.251.2
Percentage of Assets0.00.10.10.10.1
Percentage of Assets es:NstarElectricCompany0.20.20.20.20.2

es:TheConnecticutLightAndPowerCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value0.10.20.40.40.2
Percentage of OperatingLeaseLiabilityNoncurrent0.20.50.90.90.4
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value9.09.010109.6
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo dei:LegalEntity

es:TheConnecticutLightAndPowerCompany


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value0.10.20.50.20.2
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo1.12.25.01.92.1
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value6400000.07400000.08900000.09200000.08700000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value4500000.04900000.07400000.07500000.07300000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour dei:LegalEntity

es:NstarElectricCompany


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value1700000.01600000.01600000.01600000.01600000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour37.832.721.621.321.9
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value3400000.02800000.04900000.04900000.04800000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive dei:LegalEntity

es:NstarElectricCompany


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value1700000.01700000.01600000.01600000.01600000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive50.060.732.732.733.3
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-312019-12-31
Value3628
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0
Percentage of Assets0.10.1

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive dei:LegalEntity

es:NstarElectricCompany


Lessee
Period End2020-12-312019-12-31
Value2728
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive74.699.3
Percentage of Assets0.10.1
Percentage of Assets es:NstarElectricCompany0.20.2

es:PublicServiceCompanyOfNewHampshirePSNH


Lessee
Period End2020-12-312019-12-31
Value0.10.2
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive0.30.7
Percentage of Assets0.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value5549525456
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.1

us-gaap:OperatingLeaseLiability dei:LegalEntity

es:NstarElectricCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value2324242425
Percentage of OperatingLeaseLiability42.848.546.344.744.3
Percentage of Assets0.10.10.10.10.1
Percentage of Assets es:NstarElectricCompany0.20.20.20.20.2

es:PublicServiceCompanyOfNewHampshirePSNH


Operating
Period End2020-12-312019-12-31
Value0.30.4
Percentage of OperatingLeaseLiability0.50.8
Percentage of Assets0.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value0.30.70.90.60.5
Percentage of OperatingLeaseLiability0.51.41.71.10.9
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value7063656971
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.2

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue dei:LegalEntity

es:NstarElectricCompany


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value3537373738
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue49.658.556.454.254.6
Percentage of Assets0.10.10.10.10.1
Percentage of Assets es:NstarElectricCompany0.30.30.30.30.3

es:PublicServiceCompanyOfNewHampshirePSNH


Lessee
Period End2020-12-312019-12-31
Value0.40.5
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue0.60.8
Percentage of Assets0.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value0.30.80.90.70.5
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue0.41.31.41.00.7
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value1513131514
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount dei:LegalEntity

es:NstarElectricCompany


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value1112121313
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount73.996.296.288.795.2
Percentage of Assets0.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.10.10.10.10.1

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value14311142331406313980138051320912629121211195411637114861140811273111831108610998108851080410711106371050910438103521029410185101109976989097539723961195179406934592379176906740684012395639153811
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.330.630.532.132.831.730.730.530.729.930.030.430.330.230.633.233.333.433.434.234.034.033.934.334.133.833.535.335.134.634.633.533.433.032.633.133.025.525.626.927.126.3

us-gaap:StockholdersEquity dei:LegalEntity

es:NstarElectricCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value4502440845214325416040634159391537513783373036953549345434462738272326902671259424522573260925982530249824632413
Percentage of StockholdersEquity31.531.032.130.930.130.832.932.331.432.532.532.431.530.931.124.925.024.924.924.423.324.725.225.224.824.724.725.1
Percentage of Assets9.59.59.89.99.99.810.19.99.69.79.89.89.59.39.58.38.38.38.38.37.98.48.58.68.58.38.38.7
Percentage of Assets es:NstarElectricCompany34.333.835.134.934.233.535.034.133.333.733.733.933.032.132.733.133.633.633.533.732.033.534.334.933.933.633.60.0

es:PublicServiceCompanyOfNewHampshirePSNH


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value1571156215421488144014091391115111291316130213501387
Percentage of StockholdersEquity11.011.011.010.610.410.711.09.59.511.311.312.213.0
Percentage of Assets3.33.43.33.43.43.43.42.92.93.43.43.74.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH33.433.633.133.132.132.232.00.00.00.031.60.00.0

es:TheConnecticutLightAndPowerCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value5115507150444794455044344387418041364209419939213822363335873539355035093470338933543322314031192984295629362702
Percentage of StockholdersEquity35.735.635.934.333.033.634.734.534.636.236.634.433.932.532.432.232.632.532.431.931.931.830.330.329.329.229.428.1
Percentage of Assets10.810.910.911.010.810.610.710.510.610.811.010.510.39.89.910.710.910.810.810.910.910.810.310.410.09.99.99.7
Percentage of Assets es:TheConnecticutLightAndPowerCompany36.937.337.536.636.235.736.035.135.436.436.834.834.532.633.733.934.534.534.634.234.534.432.732.931.731.431.40.0

us-gaap:StockholdersEquity dei:LegalEntity, us-gaap:StatementEquityComponents

es:NstarElectricCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.5110.370.3090.3550.290.2220.155-1.035-1.147-1.261-1.378-1.498-1.608-1.717-1.8230.3680.5450.4420.0
Percentage of StockholdersEquity0.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2053199319931813181318131813166316531653163316081603159515021045995994992
Percentage of StockholdersEquity14.414.014.213.013.113.714.413.713.814.214.214.114.214.313.69.89.610.010.3
Percentage of Assets4.34.34.34.24.34.44.44.24.24.24.34.34.34.34.13.33.33.33.6
Percentage of Assets es:NstarElectricCompany us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:NstarElectricCompany, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2447241425272511234622492346225320992131209820881948186019441625161314681420
Percentage of StockholdersEquity17.117.018.018.017.017.018.618.617.618.318.318.317.316.617.515.215.614.714.8
Percentage of Assets5.25.25.55.85.65.45.75.75.45.55.55.65.25.05.45.15.34.95.1
Percentage of Assets es:NstarElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value-0.076-0.358-0.613-0.884-1.144-1.429-1.707-1.97-2.248-2.544-2.851-3.922-5.063
Percentage of StockholdersEquity-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value1088928928903903903903678678678678843843
Percentage of StockholdersEquity7.66.56.66.56.56.87.25.65.75.85.97.67.9
Percentage of Assets2.32.02.02.12.12.22.21.71.71.71.82.32.6
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value483634615586538507490475453641627511549
Percentage of StockholdersEquity3.44.54.44.23.93.83.93.93.85.55.54.65.1
Percentage of Assets1.01.41.31.31.31.21.21.21.21.61.61.41.7
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.2730.270.3020.3070.3180.3150.3160.3250.3260.3180.3010.3060.3180.3090.269-0.053-0.576-0.931-1.387
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2810281028102660253525352535241024102410241022102210211921102110191018041682
Percentage of StockholdersEquity19.619.720.019.018.419.220.119.920.220.721.019.419.619.019.019.718.518.117.5
Percentage of Assets6.06.06.16.16.06.16.26.16.26.26.35.95.95.75.86.66.26.16.1
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value224422002173207219541838179117081664173717271650155114521415129911701072961
Percentage of StockholdersEquity15.715.515.514.814.213.914.214.113.914.915.014.513.813.012.812.111.310.710.0
Percentage of Assets4.84.74.74.84.64.44.44.34.34.54.54.44.23.93.94.13.83.63.5
Percentage of Assets es:TheConnecticutLightAndPowerCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Stockholders
Period End2020-12-312019-12-312018-12-312017-12-31
Value14063126291148611086
Percentage of StockholdersEquity100.0100.0100.0100.0
Percentage of Assets30.530.730.030.6
Percentage of Assets srt:ParentCompany67.069.868.771.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Stockholders
Period End2020-12-312019-12-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value-76.1-62.8-55.1-57.2-60.2-58.1-58.8-56.5-57.5-57.3-55.6-54.6-62.3
Percentage of StockholdersEquity-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.5-0.6
Percentage of Assets-0.2-0.2-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedges


Stockholders
Period End2020-12-312019-12-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value-1.4-3.0-4.4-5.5-6.2-6.6-7.1-7.7-8.2-8.7-9.2-10.3-12.4
Percentage of StockholdersEquity-0.0-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedges0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Stockholders
Period End2020-12-312019-12-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-31
Value1.10.7-0.5-0.40.01.13.02.10.40.4-0.6-1.90.7
Percentage of StockholdersEquity0.00.0-0.0-0.00.00.00.00.00.00.0-0.0-0.00.0
Percentage of Assets0.00.0-0.0-0.00.00.00.00.00.00.0-0.0-0.00.0
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-312013-12-31
Value-74.342-75.223-76.411-60.397-62.558-63.111-65.059-52.017-53.641-57.804-60.0-59.582-60.988-63.1-66.403-63.6-62.9-62.1-65.3-65.6-65.4-66.8-74.0-46.031
Percentage of StockholdersEquity-0.5-0.5-0.5-0.4-0.5-0.5-0.5-0.4-0.4-0.5-0.5-0.5-0.5-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.7-0.5
Percentage of Assets-0.2-0.2-0.2-0.1-0.1-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value8032801680157996797974797087667566596242624162346229622462396250626262356192
Percentage of StockholdersEquity56.156.357.057.257.856.656.155.155.753.654.354.655.355.756.358.360.562.564.4
Percentage of Assets17.017.217.418.419.018.017.216.817.116.016.316.616.716.817.219.520.520.922.3
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1789178917891789178917591729169916991669166916691669166916691669166916661665
Percentage of StockholdersEquity12.512.612.712.813.013.313.714.014.214.314.514.614.814.915.115.616.116.717.3
Percentage of Assets3.83.83.94.14.34.24.24.34.44.34.44.44.54.54.65.25.55.66.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4830477246134535438443224177410039544092395338823753367035613175279724482125
Percentage of StockholdersEquity33.733.532.832.431.832.733.133.833.135.234.434.033.332.832.129.627.024.522.1
Percentage of Assets10.210.310.010.410.410.410.210.310.110.510.310.310.19.99.89.99.18.27.6
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value-265.878-268.998-277.979-281.514-284.515-288.539-299.055-301.77-304.559-309.138-317.771-317.771-317.771-317.771-317.771-317.771-309.977-300.467-326.537
Percentage of StockholdersEquity-1.9-1.9-2.0-2.0-2.1-2.2-2.4-2.5-2.5-2.7-2.8-2.8-2.8-2.8-2.9-3.0-3.0-3.0-3.4
Percentage of Assets-0.6-0.6-0.6-0.6-0.7-0.7-0.7-0.8-0.8-0.8-0.8-0.8-0.9-0.9-0.9-1.0-1.0-1.0-1.2
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value-74.4-74.6-76.1-59.6-61.3-61.2-62.8-49.3-50.4-53.9-55.1-54.3-55.4-57.2-60.2-58.1-58.8-57.5
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.2-0.2-0.2-0.1-0.1-0.1-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302016-12-31
Value-0.5-1.0-1.4-1.8-2.4-2.8-3.0-3.5-3.8-4.1-4.4-4.6-5.0-6.2-6.6-7.1-8.2
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest0.71.31.83.03.94.64.87.17.57.68.08.59.010.311.412.114.3
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedGainLossNetCashFlowHedgeParent0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value0.60.41.11.01.10.90.70.80.60.2-0.5-0.7-0.6-0.40.01.13.00.4
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-0.8-0.5-1.4-1.7-1.8-1.5-1.1-1.6-1.2-0.40.91.31.10.7-0.0-1.9-5.1-0.7
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.00.00.00.00.0
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value-74.3-75.2-76.4-60.4-62.6-63.1-65.1-52.0-53.6-57.8-60.0-59.6-61.0-63.1-66.4-63.6-62.9-65.3
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest99.9100.8100.4101.3102.1103.1103.7105.5106.3107.2108.9109.8110.1110.3110.3109.5107.0113.6
Percentage of Assets-0.2-0.2-0.2-0.1-0.1-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1789178917891789178917591729169916991669166916691669166916691669166916691669166916691669166916691669166816661666166616661665166516641664166216621662981980980979978
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.83.83.94.14.34.24.24.34.44.34.44.44.54.54.65.05.15.25.25.45.45.45.55.65.65.65.66.06.05.96.05.95.95.95.96.06.06.16.36.76.86.8

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-312018-12-312017-12-31
Value1789172916691669
Percentage of CommonStockValue100.0100.0100.0100.0
Percentage of Assets3.94.24.44.6
Percentage of Assets srt:ParentCompany8.59.610.010.7

Additional Paid In Capital

us-gaap:AdditionalPaidInCapital

us-gaap:AdditionalPaidInCapital


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value803280168015799679797479708766756659624262416234622962246239623562326230625062566252624362626260625362416235621962016185619261856176617361836183617818011797179217851777
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets17.017.217.418.419.018.017.216.817.116.016.316.616.716.817.218.819.119.319.520.120.220.320.520.820.920.820.922.222.322.022.321.721.921.821.822.322.511.311.512.212.412.3

us-gaap:AdditionalPaidInCapital dei:LegalEntity

es:NstarElectricCompany


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value20531993199318131813181318131663165316531633160816031595150210471047104510451020995995995995995995994
Percentage of AdditionalPaidInCapital25.624.924.922.722.724.225.624.924.826.526.225.825.725.624.116.816.816.816.716.315.915.915.915.915.915.915.9
Percentage of Assets4.34.34.34.24.34.44.44.24.24.24.34.34.34.34.13.23.23.23.33.33.23.23.33.33.33.33.3
Percentage of Assets es:NstarElectricCompany15.615.315.514.614.915.015.314.514.714.714.814.814.914.814.312.712.913.013.113.213.013.013.113.413.413.413.6

es:PublicServiceCompanyOfNewHampshirePSNH


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value1088928928903903903903678
Percentage of AdditionalPaidInCapital13.511.611.611.311.312.112.710.9
Percentage of Assets2.32.02.02.12.12.22.21.8
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH23.220.019.920.120.120.620.816.4

es:TheConnecticutLightAndPowerCompany


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value281028102810266025352535253524102410241024102210221021192110211021102110211020562056205619101910180518051804
Percentage of AdditionalPaidInCapital35.035.135.133.331.833.935.836.136.238.638.635.535.534.133.833.833.933.933.832.932.932.930.530.528.928.928.9
Percentage of Assets6.06.06.16.16.06.16.26.16.26.26.35.95.95.75.86.46.56.56.66.66.76.76.26.46.06.06.1
Percentage of Assets es:TheConnecticutLightAndPowerCompany20.320.720.920.320.220.420.820.220.620.921.119.619.919.019.920.220.520.721.020.721.221.319.920.119.219.219.3

us-gaap:AdditionalPaidInCapital us-gaap:ConsolidatedEntities

srt:ParentCompany


Additional
Period End2020-12-312019-12-312018-12-312017-12-31
Value8015708762416239
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0
Percentage of Assets17.417.216.317.2
Percentage of Assets srt:ParentCompany38.239.137.340.0

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value483047724613453543844322417741003954409239533882375336703561347433643284317530872962290027972747264425692448235122412237212520641969191418021735163516981651158715461452
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets10.210.310.010.410.410.410.210.310.110.510.310.310.19.99.810.510.310.29.99.99.69.49.19.18.98.68.28.48.18.07.67.37.06.86.46.35.910.610.610.810.710.0

us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity

es:NstarElectricCompany


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value244724142527251123462249234622532099213120982088194818601944169016751645162515731456157716131603153415021468
Percentage of RetainedEarningsAccumulatedDeficit50.750.654.855.453.552.056.255.053.152.153.153.851.950.754.648.749.850.151.251.049.254.457.758.358.058.560.0
Percentage of Assets5.25.25.55.85.65.45.75.75.45.55.55.65.25.05.45.15.15.15.15.14.75.15.35.35.15.04.9
Percentage of Assets es:NstarElectricCompany18.618.519.620.319.318.519.719.618.719.019.019.218.117.318.520.420.720.520.420.419.020.521.221.620.620.220.0

es:PublicServiceCompanyOfNewHampshirePSNH


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value483634615586538507490627
Percentage of RetainedEarningsAccumulatedDeficit10.013.313.312.912.311.711.715.9
Percentage of Assets1.01.41.31.31.31.21.21.6
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH10.313.613.213.012.011.611.315.2

es:TheConnecticutLightAndPowerCompany


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value224422002173207219541838179117081664173717271650155114521415136713781338129912721237120611701149111910911072
Percentage of RetainedEarningsAccumulatedDeficit46.546.147.145.744.642.542.941.742.142.543.742.541.339.639.839.441.040.840.941.241.841.641.841.842.342.543.8
Percentage of Assets4.84.74.74.84.64.44.44.34.34.54.54.44.23.93.94.14.24.14.14.14.03.93.83.83.73.63.6
Percentage of Assets es:TheConnecticutLightAndPowerCompany16.216.216.215.815.514.814.714.314.215.015.114.614.013.013.313.113.413.212.912.812.712.512.212.111.911.611.5

us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:ConsolidatedEntities

srt:ParentCompany


Retained
Period End2020-12-312019-12-312018-12-312017-12-31
Value4613417739533561
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0
Percentage of Assets10.010.210.39.8
Percentage of Assets srt:ParentCompany22.023.123.622.8

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value-74.342-75.223-76.411-60.397-62.558-63.111-65.059-52.017-53.641-57.804-60.0-59.582-60.988-63.13-66.403-63.615-62.935-62.141-65.282-65.617-65.364-65.175-66.844-73.546-72.033-72.414-74.009-40.1724144466769707264666870554543
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.2-0.2-0.2-0.1-0.1-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.10.10.20.20.20.20.30.30.20.20.40.50.40.30.3

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

es:NstarElectricCompany


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.5110.370.3090.3550.290.2220.155-1.035-1.147-1.261-1.378-1.498-1.608-1.717-1.8230.3560.360.3640.3680.5140.5240.5350.5450.2580.260.2620.442
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-0.7-0.5-0.4-0.6-0.5-0.4-0.22.02.12.22.32.52.62.72.7-0.6-0.6-0.6-0.6-0.8-0.8-0.8-0.8-0.4-0.4-0.4-0.6
Percentage of Assets0.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value-0.076-0.358-0.613-0.884-1.144-1.429-1.707-2.851
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax0.10.50.81.51.82.32.64.8
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.1

es:TheConnecticutLightAndPowerCompany


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.2730.270.3020.3070.3180.3150.3160.3250.3260.3180.3010.3060.3180.3090.2690.270.2380.114-0.053-0.165-0.309-0.456-0.576-0.735-0.748-0.816-0.931
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-0.4-0.4-0.4-0.5-0.5-0.5-0.5-0.6-0.6-0.6-0.5-0.5-0.5-0.5-0.4-0.4-0.4-0.20.10.30.50.70.91.01.01.11.3
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities

srt:ParentCompany


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value-76.411-65.059-60.0-66.403
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0
Percentage of Assets-0.2-0.2-0.2-0.2
Percentage of Assets srt:ParentCompany-0.4-0.4-0.4-0.4

Treasury Stock Value

us-gaap:TreasuryStockValue

us-gaap:TreasuryStockValue


Treasury
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value265268277281284288299301304309317317317317317317317317317309-309.977-309.977-309.977-309.977-309.977-296.119-300.467-306.98-313.903-321.063-326.537-330.464-334.873-336.803-338.624-340.688-342.632-344.774-346.667-348.764-351.387-354.732
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.60.60.60.70.70.70.80.80.80.80.80.90.90.91.01.01.01.01.0-1.0-1.0-1.0-1.0-1.0-1.0-1.0-1.1-1.1-1.1-1.2-1.2-1.2-1.2-1.2-1.2-1.2-2.2-2.2-2.4-2.4-2.5

us-gaap:TreasuryStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Treasury
Period End2020-12-312019-12-312018-12-312017-12-31
Value277299-317.771317
Percentage of TreasuryStockValue100.0100.0-100.0100.0
Percentage of Assets0.60.7-0.80.9
Percentage of Assets srt:ParentCompany1.31.7-1.92.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value396411186490585420514570496428376709520177512584471436524671478499824863734812315074024934864072954733654753118.81681201313372249309
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.514.88.620.930.018.325.526.326.617.918.730.628.07.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value731722328915161111335114136206371661362252744.83133773996896154294-13.72722115129196191
Percentage of NetCashProvidedByUsedInOperatingActivities18.542.012.559.025.814.721.658.823.132.054.852.412.776.844.047.01.030.614.759.414.419.3187.760.6-3.745.96.725.648.738.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.46.21.112.37.82.75.515.56.15.710.216.03.66.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value63746930605871813586
Percentage of NetCashProvidedByUsedInOperatingActivities16.018.237.36.210.313.913.914.27.220.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.02.73.21.33.12.53.63.71.93.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value67156-2.16811615013219418514719813618320364181269182171197184208221-123.44215113613312920717995
Percentage of NetCashProvidedByUsedInOperatingActivities17.138.0-1.223.725.831.437.932.629.746.336.425.839.136.435.346.138.739.337.627.543.544.2-149.731.236.427.855.940.944.719.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.25.6-0.14.97.75.89.78.67.98.36.87.910.92.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-793.459-704.517-2119.561-619.212-672.892-717.61-822.439-858.15-671.463-922.236-684.918-558.418-667.426-479.719-1572.379-459.567-648.771-529.757-789.186-494.8-442.222-424.6-500.634-442.706-351.285-364.525-468.579-401.787-370.275-351.154-382.245-341.159-270.906-446.913-406.588-371.589-387.278-302.469-308.731-282.148-190.763-236.945-268.207-241.894
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-37.0-25.4-97.6-26.3-34.6-31.3-40.8-39.6-35.9-38.5-34.0-24.1-35.9-21.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-210.549-215.461-251.94-207.396-199.977-247.528-225.158-217.617-210.007-208.523-186.781-182.461-163.776-192.69-361.517-95.944-129.992-135.722-196.575-127.907-108.505-91.319-155.411-126.005-108.327-79.723-155.78-96.316-117.486-95.446
Percentage of NetCashProvidedByUsedInInvestingActivities26.530.611.933.529.734.527.425.431.322.627.332.724.540.223.020.920.025.624.925.924.521.531.028.530.821.933.224.031.727.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-9.8-7.8-11.6-8.8-10.3-10.8-11.2-10.0-11.2-8.7-9.3-7.9-8.8-8.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-65.845-68.141-94.674-77.941-80.421-88.568-99.843-76.079-67.789-64.259
Percentage of NetCashProvidedByUsedInInvestingActivities8.39.74.512.612.012.312.18.910.17.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.1-2.5-4.4-3.3-4.1-3.9-5.0-3.5-3.6-2.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-195.292-197.874-224.206-202.165-194.729-212.3-218.175-233.082-276.197-189.364-203.421-202.939-255.497-202.07-202.45-201.938-238.19-181.569-173.48-149.783-141.343-138.035-164.486-116.371-118.058-125.65-126.858-156.409-112.824-106.966
Percentage of NetCashProvidedByUsedInInvestingActivities24.628.110.632.628.929.626.527.241.120.529.736.338.342.112.943.936.734.322.030.332.032.532.926.333.634.527.138.930.530.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-9.1-7.1-10.3-8.6-10.0-9.3-10.8-10.7-14.8-7.9-10.1-8.7-13.7-8.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value5892031369780131313272272233393383-138.354-93.76578971-23.475156108254-175.8-48.492-48.345406-44.017-57.014-84.966234-97.957-87.646-96.856-118.903-44.899-49.737-11.16113-59.047-179.20557021682-123.418-143.8570.607-115.57
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax27.57.463.033.26.713.713.512.612.516.419.0-6.0-5.025.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value13742233-83.47553188113-117.6718671-20.143-186.881886347-93.0531270.972116-268.4939-4.791.183-168.69107-136.485142-35.49-107.875-61.892
Percentage of NetCashProvidedByUsedInFinancingActivities23.421.017.1-10.740.660.141.6-43.237.218.3-5.3135.1-94.111.04.9396.481.40.945.9152.7-81.59.90.3383.2-187.7160.660.736.2123.163.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.41.510.8-3.52.78.25.6-5.44.73.0-1.0-8.14.72.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value13-18.3274235341340-20.04842-45.747
Percentage of NetCashProvidedByUsedInFinancingActivities2.3-9.03.14.526.44.415.0-7.418.2-11.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.6-0.71.91.51.80.62.0-0.92.3-1.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value316-39.843088751831354124-89.11615319-186.03937117-63.9814618-25.637-36.001-73.982-67.695275-31.191-25.6956.245-16.506-45.33-72.31419
Percentage of NetCashProvidedByUsedInFinancingActivities53.7-19.622.611.239.126.75.119.953.3-22.740.0-13.8198.464.21.8272.529.717.2-10.120.5152.6140.067.870.945.1-7.3-7.146.382.5-20.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.8-1.414.23.72.63.70.72.56.7-3.77.60.8-10.016.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-06-302020-03-31
Value192-89.3464316
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.0-3.22.20.7

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect dei:LegalEntity

es:NstarElectricCompany


Cash
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.525-0.0374.3532.817
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect0.30.010.116.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-0.00.20.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Cash
Period End2021-06-302021-03-312020-06-302020-03-31
Value11-11.56714-16.298
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect5.812.933.5-98.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.5-0.40.7-0.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Cash
Period End2021-06-302021-03-312020-06-302020-03-31
Value189-81.5217.2313.796
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect98.391.216.722.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.8-2.90.40.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.0

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DeferredIncomeTaxExpenseBenefit


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value7841100704244136361818104-91.481738811610512814116550109141338-23.44728148378-68.394-4.2681379777871681051267.035526338425210567
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxExpenseBenefit dei:LegalEntity

es:NstarElectricCompany


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value181059-12.626169.77516-0.5237.8813.72225-13.0356.696223910312939-7.5451532118-7.5462041147-17.675-23.3091.585
Percentage of DeferredIncomeTaxExpenseBenefit23.524.658.9-18.038.522.111.8-1.442.720.624.114.29.125.533.510.124.620.723.8-14.914.223.335.232.271.427.939.025.8546.11.2

es:PublicServiceCompanyOfNewHampshirePSNH


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-0.464-0.378-6.6224.7665.0264.1672.9570.935.4896.541
Percentage of DeferredIncomeTaxExpenseBenefit-0.6-0.9-6.66.811.99.42.22.529.836.2

es:TheConnecticutLightAndPowerCompany


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value162551591319343.4861.3251526-22.27821292916254759113958147-41.1561019145-57.653-16.08159
Percentage of DeferredIncomeTaxExpenseBenefit21.160.551.884.431.645.024.99.47.284.025.224.429.732.925.016.019.833.935.923.236.041.443.4175.537.813.138.484.3376.843.2

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value280378307302263286240296258285285301235249234236182210199225167195150151243194231210105106129108125174181143
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationDepletionAndAmortization us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2827252422211717141313121112
Percentage of DepreciationDepletionAndAmortization10.17.28.38.08.67.47.35.85.74.84.64.05.14.8

us-gaap:IntersegmentElimination


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-1.1-1.0-0.4-0.3-0.3-0.6-0.6-0.6-0.6-0.6-0.5-0.6-0.6-0.6-0.5-0.6-0.5-0.5-0.6-0.5-0.5-0.5-0.5-0.5
Percentage of DepreciationDepletionAndAmortization-0.4-0.3-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.3-0.2-0.2-0.3-0.3-0.2-0.3-0.2-0.3-0.3-0.3-0.3

us-gaap:DepreciationDepletionAndAmortization us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value132221167182140167133188150179185206135144
Percentage of DepreciationDepletionAndAmortization47.258.654.460.353.358.555.763.558.262.765.068.457.657.9

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value7473717068676564626160585756
Percentage of DepreciationDepletionAndAmortization26.619.423.223.426.123.627.221.724.121.521.019.324.222.7

us-gaap:OperatingSegments, es:EversourceWater


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1111111010111111121111111210
Percentage of DepreciationDepletionAndAmortization4.13.03.63.64.14.05.03.74.74.14.23.95.24.3

us-gaap:OperatingSegments, es:NaturalGasDistribution


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value344532142119121619201513192618151721171516151717
Percentage of DepreciationDepletionAndAmortization12.312.110.74.98.06.75.15.47.67.15.44.68.210.67.76.49.810.38.76.710.08.111.411.6

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-103.945-181.72524348-41.885-127.366172-1.278-142.521-13.556507.468-18.488-61.57115271-110.52-57.70110730-75.679-76.317142-5.484-168.68-59.49621443-166.859535714-40.463-86.91679-31.77513-190.232-47.702905.297-29.27815-6.121
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity

es:NstarElectricCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-43.125-45.60482-7.4193.581-53.4622435-64.217-18.109504.016-60.364431895-114.589-19.025-10.05665-61.936-26.83863-3.059-67.5982950-19.083-107.8286
Percentage of IncreaseDecreaseInAccountsPayable41.525.134.0-15.4-8.542.014.3-2744.145.1133.699.653.8326.5-70.111.8132.7103.733.0-9.4216.181.835.244.655.840.1-49.123.5-43.964.6160.1

es:PublicServiceCompanyOfNewHampshirePSNH


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-8.295-21.02556-37.60726-18.06424-10.941-12.92111
Percentage of IncreaseDecreaseInAccountsPayable8.011.623.3-78.0-62.814.214.2856.19.1-86.8

es:TheConnecticutLightAndPowerCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-97.13117-15.05247-22.276-27.298933.161-69.9375-61.62115-2.397-28.4084962-46.856-16.957337.969-33.097-5.043.57534-34.998-20.1945143-24.123-2.872
Percentage of IncreaseDecreaseInAccountsPayable93.4-9.4-6.298.753.221.454.4-247.349.1-556.0-122.0207.613.046.132.686.742.429.431.126.143.76.62.5-632.920.733.924.2101.114.5-5.3

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-120.401423638-110.359514229-102.981394520-92.565263218-75.483331718-66.6782213128.128-68.172145348-75.0411.6772417-28.487-1.4347.808-10.587-30.1086.9611729-42.99-4.78918
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInventories dei:LegalEntity

es:NstarElectricCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-112.254523725-108.049543325-95.708464715-82.485373318-59.27132174.535-75.5164021-4.268-31.099139.106133.7933.606
Percentage of IncreaseDecreaseInInventories93.2124.7102.867.797.9106.780.585.892.9117.8105.176.189.1138.8102.496.878.597.098.824.5113.3177.3161.7-33.7-382.6-19.864.325.07.8-4.8

es:PublicServiceCompanyOfNewHampshirePSNH


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-5.7922.2961.5712.513-5.7383.526110.68-14.081-0.144
Percentage of IncreaseDecreaseInInventories4.85.44.36.65.26.927.72.313.7-0.4

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value10342-71.442-10.5542961-93.53-34.976970-93.084-36.3712723-121.612-17.0157.09642-62.189-19.0836210-35.6610.85624-34.179-36.404-21.14653-11.282-59.143113732-28.677-44.7542440-21.988-11.214-12.6483311-25.162
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet dei:LegalEntity

es:NstarElectricCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value132-51.445-21.484-58.795120-7.033-32.689-71.559114-11.466-18.131-80.40470-23.703-11.952-59.39147-2.3716.978-38.14283-19.62.369-21.59526-51.157-6.195-29.18227-31.112
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet127.6-121.430.1557.1405.9-11.435.0204.6163.9-16.319.5221.1254.1-101.19.8349.1673.6-5.5-11.2199.9135.0-193.0-6.6-2522.8104.5149.717.0138.052.7275.8

es:PublicServiceCompanyOfNewHampshirePSNH


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value18-12.89712-13.03617-9.11810-24.37424-6.472
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet18.0-30.4-16.9123.560.0-14.7-11.069.734.5-9.2

es:TheConnecticutLightAndPowerCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-36.94621-40.81268-21.55721-40.58747-36.33340-52.81148-37.53723-58.19151-46.11732-43.13845-23.30722-21.5333-9.8127.727-9.41318-24.4358.73
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet-35.750.657.1-645.0-72.735.243.4-137.2-52.057.356.7-132.9-135.298.747.8-303.6-649.976.169.4-239.4-37.6221.960.43870.2-39.3-22.625.9-86.4-46.1-77.4

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value396411186490585420514570496428376709520177512584471436524671478499824863734812315074024934864072954733654753118.81681201313372249309
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.514.88.620.930.018.325.526.326.617.918.730.628.07.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value731722328915161111335114136206371661362252744.83133773996896154294-13.72722115129196191
Percentage of NetCashProvidedByUsedInOperatingActivities18.542.012.559.025.814.721.658.823.132.054.852.412.776.844.047.01.030.614.759.414.419.3187.760.6-3.745.96.725.648.738.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.46.21.112.37.82.75.515.56.15.710.216.03.66.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value63746930605871813586
Percentage of NetCashProvidedByUsedInOperatingActivities16.018.237.36.210.313.913.914.27.220.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.02.73.21.33.12.53.63.71.93.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value67156-2.16811615013219418514719813618320364181269182171197184208221-123.44215113613312920717995
Percentage of NetCashProvidedByUsedInOperatingActivities17.138.0-1.223.725.831.437.932.629.746.336.425.839.136.435.346.138.739.337.627.543.544.2-149.731.236.427.855.940.944.719.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.25.6-0.14.97.75.89.78.67.98.36.87.910.92.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value266368273348254336251320333102332912442712392622322612312672052461832372092552232361292371792111732291762094610011491781151311017387
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.413.312.614.813.114.712.514.81.813.011.612.513.111.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value110938116597100931548994771408777701087766521176854601188183691156058
Percentage of NetIncomeLoss41.625.529.747.638.429.837.148.3269.230.333.248.335.928.429.441.233.325.322.843.933.222.132.849.939.132.831.048.946.524.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.23.43.77.05.04.44.67.14.83.93.86.14.73.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3444284731393340263214402535
Percentage of NetIncomeLoss13.012.110.613.512.411.813.312.880.710.66.114.010.512.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.61.32.01.61.71.71.91.41.40.71.81.41.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value115981011201171188311110411079100999899969190778682877180786987833779
Percentage of NetIncomeLoss43.426.737.234.546.135.333.334.8314.435.633.934.440.836.341.436.739.234.533.732.440.335.438.833.737.627.139.035.528.933.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.43.64.75.16.05.24.25.25.64.63.94.35.44.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity, us-gaap:StatementEquityComponents

es:NstarElectricCompany, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value110931659710015489941408777
Percentage of NetIncomeLoss41.625.547.638.429.848.3269.230.348.335.928.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.23.47.05.04.47.14.83.96.14.73.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value3444473139402632
Percentage of NetIncomeLoss13.012.113.512.411.812.780.610.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.62.01.61.71.91.41.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value115981201171181111041101009998
Percentage of NetIncomeLoss43.426.734.546.135.334.8314.435.634.440.836.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.43.65.16.05.25.25.64.64.35.44.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value26636834825433632033310291244271
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.413.314.813.114.714.81.813.012.513.111.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-793.459-704.517-2119.561-619.212-672.892-717.61-822.439-858.15-671.463-922.236-684.918-558.418-667.426-479.719-1572.379-459.567-648.771-529.757-789.186-494.8-442.222-424.6-500.634-442.706-351.285-364.525-468.579-401.787-370.275-351.154-382.245-341.159-270.906-446.913-406.588-371.589-387.278-302.469-308.731-282.148-190.763-236.945-268.207-241.894
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-37.0-25.4-97.6-26.3-34.6-31.3-40.8-39.6-35.9-38.5-34.0-24.1-35.9-21.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-210.549-215.461-251.94-207.396-199.977-247.528-225.158-217.617-210.007-208.523-186.781-182.461-163.776-192.69-361.517-95.944-129.992-135.722-196.575-127.907-108.505-91.319-155.411-126.005-108.327-79.723-155.78-96.316-117.486-95.446
Percentage of NetCashProvidedByUsedInInvestingActivities26.530.611.933.529.734.527.425.431.322.627.332.724.540.223.020.920.025.624.925.924.521.531.028.530.821.933.224.031.727.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-9.8-7.8-11.6-8.8-10.3-10.8-11.2-10.0-11.2-8.7-9.3-7.9-8.8-8.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-65.845-68.141-94.674-77.941-80.421-88.568-99.843-76.079-67.789-64.259
Percentage of NetCashProvidedByUsedInInvestingActivities8.39.74.512.612.012.312.18.910.17.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.1-2.5-4.4-3.3-4.1-3.9-5.0-3.5-3.6-2.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-195.292-197.874-224.206-202.165-194.729-212.3-218.175-233.082-276.197-189.364-203.421-202.939-255.497-202.07-202.45-201.938-238.19-181.569-173.48-149.783-141.343-138.035-164.486-116.371-118.058-125.65-126.858-156.409-112.824-106.966
Percentage of NetCashProvidedByUsedInInvestingActivities24.628.110.632.628.929.626.527.241.120.529.736.338.342.112.943.936.734.322.030.332.032.532.926.333.634.527.138.930.530.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-9.1-7.1-10.3-8.6-10.0-9.3-10.8-10.7-14.8-7.9-10.1-8.7-13.7-8.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value734688841701674725782751703674638633644607705495623523617490437431546436377362486393375348383373311388390391386304327280231236276235
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment dei:LegalEntity

es:NstarElectricCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2102152512071992472252172102081861821641923619512913219612710891155125108791559511894
Percentage of PaymentsToAcquirePropertyPlantAndEquipment28.731.329.929.629.634.128.829.029.930.929.328.825.531.651.219.420.925.231.826.124.821.228.428.828.722.032.024.331.627.2

es:PublicServiceCompanyOfNewHampshirePSNH


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value65689379808899766864
Percentage of PaymentsToAcquirePropertyPlantAndEquipment9.09.911.111.411.912.212.810.19.79.5

es:TheConnecticutLightAndPowerCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value195197224202194212218233276189203202255202202201238181173149141147164116114127144150113107
Percentage of PaymentsToAcquirePropertyPlantAndEquipment26.628.726.728.928.929.327.931.039.428.131.932.039.733.328.740.838.234.728.130.632.334.130.126.830.435.229.638.230.231.0

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6247655665596870475560413442
Percentage of PaymentsToAcquirePropertyPlantAndEquipment8.56.97.78.19.78.28.89.46.78.39.46.55.37.0

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value253256297218247315243289292279243241239236
Percentage of PaymentsToAcquirePropertyPlantAndEquipment34.637.235.431.136.743.531.138.641.541.438.238.237.238.9

us-gaap:OperatingSegments, es:EversourceElectricTransmission


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value218225272271228232300237217231193227269239
Percentage of PaymentsToAcquirePropertyPlantAndEquipment29.732.732.338.733.832.138.431.631.034.330.435.941.839.4

us-gaap:OperatingSegments, es:EversourceWater


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2627343827183828302034272119
Percentage of PaymentsToAcquirePropertyPlantAndEquipment3.64.04.15.44.12.54.93.84.43.15.44.43.33.1

us-gaap:OperatingSegments, es:NaturalGasDistribution


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value1741311711171069913212511587106957970887075648565525262
Percentage of PaymentsToAcquirePropertyPlantAndEquipment23.719.120.416.715.813.716.916.716.413.016.615.012.411.612.514.212.112.313.813.312.112.111.4

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value5892031369780131313272272233393383-138.354-93.76578971-23.475156108254-175.8-48.492-48.345406-44.017-57.014-84.966234-97.957-87.646-96.856-118.903-44.899-49.737-11.16113-59.047-179.20557021682-123.418-143.8570.607-115.57
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax27.57.463.033.26.713.713.512.612.516.419.0-6.0-5.025.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

es:NstarElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value13742233-83.47553188113-117.6718671-20.143-186.881886347-93.0531270.972116-268.4939-4.791.183-168.69107-136.485142-35.49-107.875-61.892
Percentage of NetCashProvidedByUsedInFinancingActivities23.421.017.1-10.740.660.141.6-43.237.218.3-5.3135.1-94.111.04.9396.481.40.945.9152.7-81.59.90.3383.2-187.7160.660.736.2123.163.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.41.510.8-3.52.78.25.6-5.44.73.0-1.0-8.14.72.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value13-18.3274235341340-20.04842-45.747
Percentage of NetCashProvidedByUsedInFinancingActivities2.3-9.03.14.526.44.415.0-7.418.2-11.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.6-0.71.91.51.80.62.0-0.92.3-1.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value316-39.843088751831354124-89.11615319-186.03937117-63.9814618-25.637-36.001-73.982-67.695275-31.191-25.6956.245-16.506-45.33-72.31419
Percentage of NetCashProvidedByUsedInFinancingActivities53.7-19.622.611.239.126.75.119.953.3-22.740.0-13.8198.464.21.8272.529.717.2-10.120.5152.6140.067.870.945.1-7.3-7.146.382.5-20.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.8-1.414.23.72.63.70.72.56.7-3.77.60.8-10.016.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:ProceedsFromIssuanceOfLongTermDebt


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value117535040014201907504547510000.09001500.0115012503003506000.00.030050040075300450750.02504003300.09504005500.00.03002452601220.00.00.0
Percentage of ProceedsFromIssuanceOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.0100.00.00.00.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity

es:NstarElectricCompany


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.00.00.04000.00.04000.00.00.03500.00.00.02500.00.00.00.00.00.0300
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.00.053.30.00.040.00.00.00.028.00.00.00.062.50.00.00.00.00.00.075.0

es:PublicServiceCompanyOfNewHampshirePSNH


Proceeds
Period End2020-12-312020-09-302019-12-312019-09-30
Value0.01500.00.0
Percentage of ProceedsFromIssuanceOfLongTermDebt0.010.60.00.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-302010-12-312010-09-30
Value4505722531502205500.4180.2222501890.4347101504251700.01500.00.02000.00.0501660.0-0.09920030175894793600.0571-0.1382450.00.00.0
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.00.00.0

us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity

es:NstarElectricCompany


Repayments
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-30
Value0.00.00.0950.00.04000.00.00.00.00.00.00.0
Percentage of RepaymentsOfLongTermDebt0.00.00.043.10.00.094.10.00.00.00.00.0-0.00.0

es:PublicServiceCompanyOfNewHampshirePSNH


Repayments
Period End2021-06-302021-03-31
Value160122
Percentage of RepaymentsOfLongTermDebt35.621.3

us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

es:Aquarion, es:Aquarion3.54SeniorNotes, us-gaap:SeniorNotes


Repayments
Period End2020-07-30
Value32
Percentage of RepaymentsOfLongTermDebt0.0

es:Aquarion, es:AquarionTermLoansAndMortgageBonds, es:TermLoansAndMortgageBonds


Repayments
Period End2020-09-30
Value32
Percentage of RepaymentsOfLongTermDebt101.3

es:Aquarion, es:AquarionWaterCompanyOfConnecticut550Notes, us-gaap:SeniorNotes


Repayments
Period End2021-04-30
Value40
Percentage of RepaymentsOfLongTermDebt0.0

es:NSTARGasCompany, es:NSTARGas995SeriesJFirstMortgageBonds, us-gaap:SeniorNotes


Repayments
Period End2020-12-31
Value25
Percentage of RepaymentsOfLongTermDebt100.0

es:NstarElectricCompany, es:NSTARElectric350SeriesFSeniorNotes, us-gaap:SeniorNotes


Repayments
Period End2021-06-30
Value250
Percentage of RepaymentsOfLongTermDebt55.6

es:PublicServiceCompanyOfNewHampshirePSNH, es:A4050SeriesQFirstMortgageBonds, us-gaap:SeniorNotes


Repayments
Period End2021-03-31
Value122
Percentage of RepaymentsOfLongTermDebt21.3

es:PublicServiceCompanyOfNewHampshirePSNH, es:PSNH320SeriesRFirstMortgageBonds, us-gaap:SeniorNotes


Repayments
Period End2021-06-30
Value160
Percentage of RepaymentsOfLongTermDebt35.6

us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

es:Aquarion, es:AquarionWaterCompanyOfConnecticut550Notes, us-gaap:SeniorNotes, us-gaap:SubsequentEvent


Repayments
Period End2021-04-30
Value40
Percentage of RepaymentsOfLongTermDebt0.0

us-gaap:RepaymentsOfLongTermDebt us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

srt:ParentCompany, es:EversourceParent250SeriesISeniorNotes, us-gaap:SeniorNotes


Repayments
Period End2021-02-28
Value450
Percentage of RepaymentsOfLongTermDebt0.0

Payments Of Dividends Common Stock

us-gaap:PaymentsOfDividendsCommonStock

us-gaap:PaymentsOfDividendsCommonStock


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value20120118918818518116717215316916016016016015015015015014114114114113213213213211911811811812110911511610710710752484848484545
Percentage of PaymentsOfDividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfDividendsCommonStock dei:LegalEntity

es:NstarElectricCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value76206650.00.01960.00.012160670.00.016186934646-0.0010.018890494949490.00.00.0253
Percentage of PaymentsOfDividendsCommonStock38.2102.734.70.00.0108.20.00.078.935.741.90.00.0100.657.161.830.930.9-0.00.0133.264.037.437.437.437.40.00.00.0213.6

es:PublicServiceCompanyOfNewHampshirePSNH


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value185250.00.00.022191921419
Percentage of PaymentsOfDividendsCommonStock92.012.50.00.00.012.311.311.0139.311.2

es:TheConnecticutLightAndPowerCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value70700.00.00.0690.066176990.00.00.060491064949494949494949494942424242
Percentage of PaymentsOfDividendsCommonStock34.834.90.00.00.038.30.038.6114.958.30.00.00.037.533.070.433.033.035.435.435.435.437.037.037.037.035.936.036.136.1

Deferred Tax Liabilities

us-gaap:DeferredTaxLiabilities

us-gaap:DeferredTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value61675739542851927097658962755695573634022858
Percentage of DeferredTaxLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilities dei:LegalEntity

es:NstarElectricCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value2008191218471753210519751841
Percentage of DeferredTaxLiabilities32.633.334.033.829.730.029.3

es:PublicServiceCompanyOfNewHampshirePSNH


Deferred
Period End2020-12-312019-12-312018-12-31
Value737706677
Percentage of DeferredTaxLiabilities12.012.312.5

es:TheConnecticutLightAndPowerCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value2115193718411760241722342157
Percentage of DeferredTaxLiabilities34.333.733.933.934.133.934.4

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value20721983192218941490144216471559213015511213
Percentage of DeferredTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsNet dei:LegalEntity

es:NstarElectricCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value548554552477269214
Percentage of DeferredTaxAssetsNet26.528.028.825.218.114.9

es:PublicServiceCompanyOfNewHampshirePSNH


Deferred
Period End2020-12-312019-12-312018-12-31
Value199199195
Percentage of DeferredTaxAssetsNet9.610.110.2

es:TheConnecticutLightAndPowerCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value707692674657429413481
Percentage of DeferredTaxAssetsNet34.134.935.134.728.828.729.2

Unrecognized Tax Benefits

us-gaap:UnrecognizedTaxBenefits

us-gaap:UnrecognizedTaxBenefits


Unrecognized
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value61554551484846388373101124156
Percentage of UnrecognizedTaxBenefits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecognizedTaxBenefits dei:LegalEntity

es:TheConnecticutLightAndPowerCompany


Unrecognized
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value252318181513141149
Percentage of UnrecognizedTaxBenefits41.742.039.735.031.628.131.029.859.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value484319145.13.75.1244.24.619
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsValuationAllowance dei:LegalEntity

es:TheConnecticutLightAndPowerCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value3324106.34.53.14.0
Percentage of DeferredTaxAssetsValuationAllowance69.857.954.943.288.283.878.4

Proceeds From Repayments Of Short Term Debt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt


Proceeds
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value83669-433.0-332.92-408.95522-16.5-1010.43829-157.2-123.61141-240.005304-20.5-38.0-173.0414-32.5-2.5-391.45314561-49.8-399.57527921986-299.5-225.0548-492.5-228.017095215343287-107.0-52.0-78.0111-1.313
Percentage of ProceedsFromRepaymentsOfShortTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromRepaymentsOfShortTermDebt dei:LegalEntity

es:NstarElectricCompany


Proceeds
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value112248-81.55477-17.5-135.0-205.438938-207.31801331830.0-174.54890-293.018086-196.0-118.7161-86.5142-35.0194-103.5
Percentage of ProceedsFromRepaymentsOfShortTermDebt134.537.118.8-16.2-19.0-3.3818.220.310.8-24.2167.757.1-55.460.1-0.0459.2-27.721.9901.5-7220.0-22.0-134.8-192.1-324.721.651.1-16.0224.934.6

es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal

es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value413230301520
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal100.0100.0100.0100.0100.0100.0

es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal dei:LegalEntity

es:NstarElectricCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value11-0.1159.1-0.20.0
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal28.7-0.351.629.8-1.30.0

es:PublicServiceCompanyOfNewHampshirePSNH


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-0.31.21.83.21.11.3
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal-0.73.75.910.57.16.4

es:TheConnecticutLightAndPowerCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value17198.0161014
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal42.859.726.152.865.472.4

es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal dei:LegalEntity, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

es:NstarElectricCompany, es:HardshipAccounts


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value4.9-8.56.7-1.3-3.7-3.4