CNP


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

Table of contents



us-gaap:CommonStockValue
us-gaap:StatementClassOfStock
us-gaap:PreferredStockParOrStatedValuePerShare
us-gaap:StatementEquityComponents
us-gaap:CommonStockSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic
us-gaap:StatementClassOfStock
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity

us-gaap:CostOfGoodsAndServicesSold
dei:LegalEntity
dei:LegalEntity
us-gaap:CostOfRevenue
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:CostsAndExpenses
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperations
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
dei:LegalEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

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

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:IncomeTaxesPaidNet
dei:LegalEntity

us-gaap:InterestAndDebtExpense
dei:LegalEntity

us-gaap:InterestPaidNet
dei:LegalEntity

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

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementOperatingActivitiesSegment

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NonoperatingIncomeExpense
dei:LegalEntity

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

us-gaap:OtherNonoperatingIncomeExpense
dei:LegalEntity

us-gaap:PreferredStockDividendsIncomeStatementImpact
us-gaap:StatementClassOfStock

us-gaap:RegulatedOperatingRevenue
dei:LegalEntity

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

us-gaap:Revenues
dei:LegalEntity
dei:LegalEntity, us-gaap:MajorCustomers
dei:LegalEntity, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

us-gaap:UnregulatedOperatingRevenue
dei:LegalEntity

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

us-gaap:LiabilitiesAndStockholdersEquity
dei:LegalEntity

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

us-gaap:AssetsCurrent
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:CashAndCashEquivalentsAtCarryingValue
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity

us-gaap:MarketableSecuritiesCurrent
us-gaap:FinancialInstrument

us-gaap:AccountsReceivableNetCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities

us-gaap:InventoryRawMaterialsAndSupplies
dei:LegalEntity

us-gaap:PrepaidExpenseAndOtherAssetsCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities
dei:LegalEntity
us-gaap:AssetsNoncurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:PropertyPlantAndEquipmentGross
dei:LegalEntity
dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
dei:LegalEntity
dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:AmortizationOfIntangibleAssets
us-gaap:IncomeStatementLocation

us-gaap:PropertyPlantAndEquipmentNet
dei:LegalEntity
dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:Goodwill
dei:LegalEntity
us-gaap:StatementBusinessSegments

us-gaap:FiniteLivedIntangibleAssetsNet
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:OperatingLeaseRightOfUseAsset
dei:LegalEntity

us-gaap:OtherAssetsNoncurrent
dei:LegalEntity

us-gaap:AccountsPayableCurrent
dei:LegalEntity

us-gaap:ContractWithCustomerLiabilityCurrent
dei:LegalEntity

us-gaap:DebtCurrent
dei:LegalEntity

us-gaap:DividendsPayableCurrent

us-gaap:LiabilitiesCurrent
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
dei:LegalEntity
us-gaap:OperatingLeaseLiabilityCurrent
us-gaap:BalanceSheetLocation

us-gaap:OtherLiabilitiesCurrent
dei:LegalEntity

us-gaap:TaxesPayableCurrent
dei:LegalEntity
dei:LegalEntity
us-gaap:LiabilitiesNoncurrent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:LongTermDebt
dei:LegalEntity

us-gaap:LongTermDebtNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:DeferredFinanceCostsNoncurrentNet
us-gaap:LongtermDebtType

us-gaap:DeferredIncomeTaxLiabilitiesNet
dei:LegalEntity

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:MinorityInterest

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity
dei:LegalEntity
us-gaap:OperatingLeaseLiabilityNoncurrent
us-gaap:BalanceSheetLocation

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive
dei:LegalEntity
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:OperatingLeaseLiability
us-gaap:BalanceSheetLocation

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
dei:LegalEntity

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

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapital
dei:LegalEntity

us-gaap:RetainedEarningsAccumulatedDeficit
dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:MinorityInterest
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:AmortizationOfFinancingCosts
dei:LegalEntity

us-gaap:DeferredIncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:DepreciationDepletionAndAmortization
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:IncreaseDecreaseInAccountsPayable
dei:LegalEntity

us-gaap:IncreaseDecreaseInInventories
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:PaymentsToAcquireProductiveAssets
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity
dei:LegalEntity
us-gaap:PaymentsOfDividends

us-gaap:PaymentsOfDividendsCommonStock
dei:LegalEntity
us-gaap:EffectiveIncomeTaxRateContinuingOperations
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment
us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxLiabilities
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxAssetsNet
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:UnrecognizedTaxBenefits

us-gaap:DeferredTaxAssetsValuationAllowance
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:Accountspayablerelatedtocapitalexpendituresdiscontinuedoperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:AmortizationofBeneficialConversionFeature
us-gaap:StatementEquityComponents

cnp:AmountOfAllowedEquityReturnRecognizedInPeriod
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:AnnualizedfeereceivedforretainedCESobligationguarantees
dei:LegalEntity, us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:BasisDifferenceAccretionGain
dei:LegalEntity
cnp:CapitalDistributiontoParent

cnp:ComprehensiveIncomeNetofTaxBeforePreferredStockDividend
dei:LegalEntity, us-gaap:StatementEquityComponents
cnp:ContributionFromParent
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:PreferredUnitsByName, us-gaap:SubsequentEventType
cnp:CostMethodInvestmentDividendsOrDistributions
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:CurrentTaxExpenseBenefitOfCashTaxesPayableUponSale
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:DilutionLossEquityMethodInvestment
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationafterDisposalPipelineconstructionandrepaircharges
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DiscontinuedoperationCapitalizedfees
dei:LegalEntity, us-gaap:IncomeTaxAuthority
cnp:DisposalGroupHeldForSaleIncomeTaxExpenseBenefit
us-gaap:IncomeTaxAuthority

cnp:DisposalGroupIncludingDiscontinuedOperationOperationandMaintenanceExpense
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

cnp:DisposalGroupIncludingDiscontinuedOperationTaxesOtherthanIncomeTaxes
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents
cnp:EffectOfAdoptionOfNewAccountingStandard
us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentGrossEquityInEarningsLosses
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentsImpairmentOnAnEquityMethodInvestment
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:EstimatedRemainingExposure
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, us-gaap:SubsequentEventType

cnp:GainLossOnIndexedDebtSecurities

cnp:Goodwillimpairmentandlossfromreclassificationtoheldforsale
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:IncentiveDistributionRightMaximum
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
cnp:IncentiveDistributionRightPercentage
dei:LegalEntity
cnp:IncreaseDecreaseInAccountsReceivablePayableAffiliates

cnp:IncreaseDecreaseInContractWithCustomerAssetOtherAccruedUnbilledReceivables
dei:LegalEntity

cnp:IncreaseDecreaseInterestAndTaxesAccrued
dei:LegalEntity

cnp:IncreaseDecreaseinAccountsReceivableonContractswithCustomers
dei:LegalEntity

cnp:IndexedDebtSecuritiesGainLoss

cnp:InterestIncomeonTransitionandSystemRestorationBonds
dei:LegalEntity

cnp:InterestOnTransitionAndSystemRestorationBonds
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:InventoryWritedowndiscontinuedoperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:Lossfromreclassificationtoheldforsale
dei:LegalEntity, us-gaap:PartnerTypeOfPartnersCapitalAccount
cnp:ManagementRightsOwnershipPercentage
dei:LegalEntity, us-gaap:IncomeStatementLocation
cnp:Netaffiliateservicechargesbillings

cnp:Noncashtransactionbeneficialconversionfeature
us-gaap:StatementEquityComponents

cnp:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationToRegulatoryAssetAfterTax
dei:LegalEntity

cnp:OtherRevenueExcludingAssessedTax
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
dei:LegalEntity, us-gaap:CreditFacility
cnp:PercentageOnLimitationOfDebtToTotalCapitalizationUnderCovenantInHundredths
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:CreditFacility

cnp:Percentageofworkyettobecompletedonprojectswithopensuretybonds
dei:LegalEntity, us-gaap:Range, us-gaap:CreditFacility
cnp:Percentageonlimitationofdebttototalcapitalizationundercovenantamendedinhundredths
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:Range, us-gaap:CreditFacility
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:QuarterlyincreaseoffeereceivedforretainedCESguaranteeexposure
dei:LegalEntity, us-gaap:StatementBusinessSegments

cnp:Reclassificationofnetdeferredlossfromcashflowhedges3
dei:LegalEntity
us-gaap:UnusualRiskOrUncertaintyByNature
cnp:Recognizedtaxbenefitfromchangesintaxlaws
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
cnp:RestorationCostExpectedCost
dei:LegalEntity
cnp:RestorationCosts

cnp:SaleofUnitsPercentageTriggerRightofFirstRefusal
dei:LegalEntity
dei:LegalEntity, us-gaap:Range, us-gaap:EnvironmentalRemediationSite
cnp:SiteContingencyLossExposure
us-gaap:Range, us-gaap:EnvironmentalRemediationSite
us-gaap:DebtInstrument
cnp:SubordinatedNoteCashExchangeablePercentageOfFairValue
us-gaap:LongtermDebtType

cnp:TotaldistributionsreceivedfromEnable
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalOther
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:CapitalExpenditureDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:CapitalExpendituresIncurredButNotYetPaid
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
dei:LegalEntity
cnp:Period, us-gaap:StatementClassOfStock
us-gaap:CommonStockDividendsPerShareCashPaid
us-gaap:StatementClassOfStock

us-gaap:CommonStockDividendsPerShareDeclared
us-gaap:StatementClassOfStock
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType

us-gaap:ContractWithCustomerLiabilityRevenueRecognized
dei:LegalEntity
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:VariableRate
us-gaap:DebtInstrumentBasisSpreadOnVariableRate1
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:VariableRate
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility, us-gaap:VariableRate
us-gaap:CreditFacility, us-gaap:VariableRate
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:DebtInstrumentRedemptionPricePercentage
us-gaap:IncomeTaxAuthority
us-gaap:DeferredIncomeTaxesAndTaxCredits
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanContributionsByEmployer
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet
us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationAfterDisposalExpense
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationIntraEntityAmountsDiscontinuedOperationAfterDisposalRevenue
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherExpense

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType
us-gaap:DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:DividendsCash
us-gaap:StatementClassOfStock
us-gaap:DividendsCommonStockCash
us-gaap:StatementEquityComponents
us-gaap:StatementClassOfStock
us-gaap:DividendsPreferredStockCash
us-gaap:StatementClassOfStock, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:EquityMethodInvestmentDividendsOrDistributions
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:LimitedPartnersCapitalAccountByClass, us-gaap:SubsequentEventType
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementEquityComponents
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOtherThanTemporaryImpairment

us-gaap:GainLossOnSalesOfAssetsAndAssetImpairmentCharges
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:GoodwillImpairmentLoss
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:StatementBusinessSegments
us-gaap:StatementOperatingActivitiesSegment

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:IncomeLossFromEquityMethodInvestments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables
dei:LegalEntity

us-gaap:IncreaseDecreaseInContractWithCustomerAsset

us-gaap:IncreaseDecreaseInContractWithCustomerLiability
dei:LegalEntity

us-gaap:IncreaseDecreaseInDerivativeAssetsAndLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInMarginDepositsOutstanding
dei:LegalEntity
dei:LegalEntity
us-gaap:IncreaseDecreaseInNotesPayableRelatedParties
dei:LegalEntity
us-gaap:IncreaseDecreaseInNotesReceivableRelatedParties

us-gaap:IncreaseDecreaseInOtherCurrentAssets
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherCurrentLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherNoncurrentAssets
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherNoncurrentLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInOverUnderEnergyRecovery
dei:LegalEntity

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
dei:LegalEntity
us-gaap:StatementClassOfStock
us-gaap:IncrementalCommonSharesAttributableToConversionOfPreferredStock
us-gaap:AwardType
us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:InterestIncomeOther
dei:LegalEntity

us-gaap:InventoryWriteDown
dei:LegalEntity

us-gaap:LeaseIncome

us-gaap:MarketableSecuritiesGainLoss

us-gaap:MarketableSecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairments

us-gaap:NetIncomeLossFromContinuingOperationsAvailableToCommonShareholdersBasic

us-gaap:NetIncomeLossFromContinuingOperationsAvailableToCommonShareholdersDiluted

us-gaap:OciEquityMethodInvestmentAfterTax

us-gaap:OciEquityMethodInvestmentBeforeTax

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:OtherComprehensiveIncomeLossTaxPortionAttributableToParent1
dei:LegalEntity

us-gaap:OtherOperatingActivitiesCashFlowStatement
dei:LegalEntity
us-gaap:TitleOfIndividual, us-gaap:SubsequentEventType
us-gaap:PaymentsForPostemploymentBenefits

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsOfDebtIssuanceCosts
dei:LegalEntity

us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock

us-gaap:PensionContributions

us-gaap:PreferredStockDividendsAndOtherAdjustments
cnp:Period, us-gaap:StatementClassOfStock
us-gaap:PreferredStockDividendsPerShareCashPaid
us-gaap:StatementClassOfStock
cnp:Period, us-gaap:StatementClassOfStock
us-gaap:PreferredStockDividendsPerShareDeclared
us-gaap:StatementClassOfStock
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType

us-gaap:ProceedsFromDivestitureOfBusinesses
dei:LegalEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:SubsequentEventType

us-gaap:ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromIssuanceOfPreferredStockAndPreferenceStock

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfCommercialPaper
dei:LegalEntity

us-gaap:ProceedsFromShortTermDebt
dei:LegalEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:RecoveryOfDirectCosts
us-gaap:SubsequentEventType
dei:LegalEntity
us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty
dei:LegalEntity, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RelatedPartyTransactionSellingGeneralAndAdministrativeExpensesFromTransactionsWithRelatedParty
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:RepaymentsOfDebt

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability
dei:LegalEntity
dei:LegalEntity
us-gaap:SaleOfStockPercentageOfOwnershipAfterTransaction
us-gaap:StatementClassOfStock
us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueConversionOfConvertibleSecurities
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation

us-gaap:TaxesExcludingIncomeAndExciseTaxes
dei:LegalEntity

us-gaap:UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic

us-gaap:UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses
dei:LegalEntity
dei:LegalEntity, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:VariableInterestEntityOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:AccountsReceivableforContractswithCustomers
dei:LegalEntity

cnp:AccruedUnbilledRevenuesAllowanceforCreditLossesCurrent
dei:LegalEntity
dei:LegalEntity
cnp:AdditionalDebtIssueable
dei:LegalEntity
cnp:Additionalfirstmortgagebondsandgeneralmortgagebondsthatcouldbeissued

cnp:AmountOfAllowedEquityReturnNotRecognizedInPeriod
dei:LegalEntity

cnp:AssetsNoncurrentOtherThanPropertyPlantAndEquipment
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryAgency
cnp:COVID19ERPRegulatoryAsset
us-gaap:RegulatoryAgency
dei:LegalEntity, us-gaap:RegulatoryAgency
cnp:COVID19ERPRegulatoryLiability
us-gaap:RegulatoryAgency
us-gaap:DebtInstrument
cnp:DebtInstrumentContingentPrincipalAmountOutstanding
us-gaap:LongtermDebtType
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
cnp:DebtInstrumentInitialInterestRateStatedPercentage

cnp:DeferredTaxAssetsNoncurrentOther
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

cnp:DeferredTaxLiabilitiesNoncurrentOther
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
cnp:DefinedBenefitPlanFairValueObligationToReturnCashReceivedAsCollateralFromSecuritiesLending
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
cnp:DefinedBenefitsPlanFairValueOfPlanAssetsExcludingInvestmentsMeasuredatNetAssetValue
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DiscontinuedOperationAfterDisposalPurchaseObligation
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:Discontinuedoperationafterdisposalpurchaseobligation
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsContractWithCustomerAssetCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsCustomerDepositsCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsMaterialsAndSuppliesCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsNaturalGasInventoryCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsPropertyPlantAndEquipmentNetCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsRegulatoryAssetsCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsRegulatoryLiabilitiesCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:DisposalGroupIncludingDiscontinuedOperationsShortTermDebtCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:SubsequentEventType
cnp:EnableSeriesADistributionRate
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentBasisDifference
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentCarryingValuePerUnit
dei:LegalEntity
cnp:EquityMethodInvestmentSummarizedFinancialInformationAccumulatedOtherComprehensiveIncomeLoss
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
cnp:EquityMethodInvestmentSummarizedFinancialInformationPreferredEquity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
cnp:FairValueAssetsMeasuredOnRecurringBasisCorporateEquities
dei:LegalEntity, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:FairValueOfDisposalGroup
dei:LegalEntity, us-gaap:SubsequentEventType
cnp:FinancingCommitments
dei:LegalEntity
cnp:GeneralMortgageBondsUsedAsCollateral
dei:LegalEntity
cnp:IncrementalUncollectibleReceivablesRegulatoryAsset
dei:LegalEntity, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

cnp:IndexedDebtCurrent
us-gaap:FinancialInstrument

cnp:IndexedDebtSecuritiesDerivative
us-gaap:FinancialInstrument

cnp:LeaseRightOfUseAsset
dei:LegalEntity

cnp:LengthOfPipeline
us-gaap:SubsequentEventType

cnp:LesseeOperatingLeaseNotYetCommenced
dei:LegalEntity, us-gaap:LongtermDebtType
cnp:LongtermDebtGrossCurrent
us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:LongtermDebtType
cnp:LongtermDebtGrossNoncurrent
us-gaap:LongtermDebtType

cnp:MergerExchangeRatio
us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:BalanceSheetLocation
cnp:MoneyPoolBorrowings
dei:LegalEntity, us-gaap:BalanceSheetLocation
cnp:MoneyPoolInvestments
dei:LegalEntity, us-gaap:RelatedPartyTransaction
cnp:MoneyPoolInvestmentsWeightedAverageInterestRate
dei:LegalEntity, us-gaap:RelatedPartyTransaction
cnp:MoneyPoolWeightedAverageInterestRate
dei:LegalEntity
cnp:PaymentDuePartnerUponTerminationOfPartnership
us-gaap:BalanceSheetLocation
cnp:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrentSplitDollarLifeInsurance
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:StatementClassOfStock
cnp:PercentageOfInvestmentInCompanyCommonStock
dei:LegalEntity
cnp:Percentageofpropertyadditions

cnp:Performanceguaranteeobligationsoutstandingfaceamount
us-gaap:StatementClassOfStock
cnp:PreferredStockConvertibleConversionPrice
cnp:PreferredStockRedemptionPeriod, us-gaap:StatementClassOfStock
cnp:PreferredStockRedemptionPercentageofLiquidationValue
us-gaap:StatementClassOfStock
cnp:PreferredStockSharesToBeConvertedToCommon
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:StatementClassOfStock
cnp:Preferredstockconvertiblethresholdindays

cnp:ProceedsFromMergerInterest
us-gaap:SubsequentEventType

cnp:ProceedsFromMergerPreferredUnits
us-gaap:SubsequentEventType
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:ReceivableFromSaleOfDisposalGroup
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations, us-gaap:SubsequentEventType
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
cnp:Receivablefromsaleofdisposalgroup
dei:LegalEntity, us-gaap:LongtermDebtType
cnp:ReplacementFundRequirements
us-gaap:StatementClassOfStock
cnp:SharesIssuedUponConversion
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:LongtermDebtType
cnp:SinkingFundRequirements
us-gaap:LongtermDebtType
cnp:SubordinatedNoteCashExchangeAmountPerEach1000OfOriginalNote

cnp:TotalAssetsClassifiedasHeldForSaleCurrentandNoncurrent

cnp:TotalAssetsClassifiedasHeldForUseCurrentandNoncurrent
dei:LegalEntity

cnp:TransitionAndSystemRestorationBondsLongTermDebtCurrent
dei:LegalEntity

cnp:TransitionAndSystemRestorationBondsLongTermDebtNonCurrent
dei:LegalEntity

cnp:UnrecognizedEquityReturn
dei:LegalEntity

cnp:WarrantyObligationsOutstandingFaceAmount

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity
us-gaap:AccountsAndNotesReceivableNet
dei:LegalEntity, us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsPayableRelatedPartiesCurrent
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
dei:LegalEntity, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsReceivableRelatedParties
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:EnvironmentalRemediationSite
us-gaap:AccrualForEnvironmentalLossContingencies

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax
dei:LegalEntity

us-gaap:AdditionalCollateralAggregateFairValue

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity

us-gaap:AssetRetirementObligation
dei:LegalEntity

us-gaap:AssetsFairValueDisclosure
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
dei:LegalEntity, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:CollateralAlreadyPostedAggregateFairValue

us-gaap:ContractWithCustomerAssetNetCurrent

us-gaap:ContractWithCustomerLiability
dei:LegalEntity
us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange, us-gaap:StatementClassOfStock
us-gaap:ConvertiblePreferredStockSharesIssuedUponConversion

us-gaap:CostMethodInvestments
dei:LegalEntity
us-gaap:DebtInstrumentCarryingAmount
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:ExtinguishmentOfDebt
us-gaap:DebtInstrumentFaceAmount
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:ExtinguishmentOfDebt, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:ExtinguishmentOfDebt
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrument
us-gaap:DebtInstrument, us-gaap:ExtinguishmentOfDebt
us-gaap:DebtInstrument, us-gaap:ExtinguishmentOfDebt, us-gaap:LongtermDebtType
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:ExtinguishmentOfDebt, us-gaap:LongtermDebtType
us-gaap:LongtermDebtType

us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet
dei:LegalEntity
dei:LegalEntity, us-gaap:CreditFacility
us-gaap:DebtWeightedAverageInterestRate
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:DeferredCompensationLiabilityClassifiedNoncurrent
us-gaap:BalanceSheetLocation

us-gaap:DeferredIncomeTaxLiabilities
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxAssetsDerivativeInstruments

us-gaap:DeferredTaxAssetsOtherTaxCarryforwards
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxAssetsRegulatoryAssetsAndLiabilities
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxLiabilitiesInvestmentInNoncontrolledAffiliates

us-gaap:DeferredTaxLiabilitiesInvestments

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment

us-gaap:DeferredTaxLiabilitiesRegulatoryAssetsAndLiabilities
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementOperatingActivitiesSegment
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationWeightedAverageInterestCreditingRate
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsCurrentFiscalYear
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:Range, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
us-gaap:Range, us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation
dei:LegalEntity, us-gaap:Range, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:Range, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:InvestmentType, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:InvestmentType, us-gaap:RetirementPlanType
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeAssets
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeAssetsCurrent

us-gaap:DerivativeFairValueOfDerivativeAsset
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:HedgingDesignation
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilities

us-gaap:DerivativeLiabilitiesCurrent

us-gaap:DerivativeLiabilitiesNoncurrent
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement
us-gaap:DerivativeInstrumentRisk, us-gaap:DerivativeInstrumentsGainLossByHedgingRelationship
us-gaap:DerivativeLiabilityNotionalAmount

us-gaap:DerivativeNetLiabilityPositionAggregateFairValue
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccruedIncomeTaxesPayable
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationDeferredTaxLiabilities
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationGoodwill1
dei:LegalEntity
us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationGoodwillCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity
us-gaap:DueFromRelatedPartiesCurrent
dei:LegalEntity
us-gaap:DueToRelatedPartiesCurrent
us-gaap:AwardType
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:EnergyRelatedInventoryNaturalGasInStorage
dei:LegalEntity
dei:LegalEntity, us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentUnderlyingEquityInNetAssets

us-gaap:EquityMethodInvestments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:ExcessOfReplacementOrCurrentCostsOverStatedLIFOValue

us-gaap:FinancialLiabilitiesFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo

us-gaap:FiniteLivedIntangibleAssetsGross
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:StatementBusinessSegments
us-gaap:GoodwillFairValueDisclosure
us-gaap:StatementBusinessSegments
us-gaap:GoodwillImpairedAccumulatedImpairmentLoss

us-gaap:GuaranteeObligationsMaximumExposure

us-gaap:IncomeTaxesReceivable

us-gaap:InterestPayableCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:InvestmentsFairValueDisclosure
dei:LegalEntity, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency
us-gaap:ConsolidatedEntities
us-gaap:JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService
us-gaap:ConsolidatedEntities
us-gaap:JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation

us-gaap:LIFOInventoryAmount
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceived
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThereafter

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:LiabilitiesOtherThanLongtermDebtNoncurrent
dei:LegalEntity

us-gaap:LiabilityForUncertainTaxPositionsNoncurrent
dei:LegalEntity
us-gaap:LimitedPartnersCapitalAccount
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
dei:LegalEntity, us-gaap:CreditFacility
us-gaap:LineOfCredit
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:ConsolidatedEntities, us-gaap:Range, us-gaap:CreditFacility
us-gaap:CreditFacility
us-gaap:SubsequentEventType

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
dei:LegalEntity
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtFairValue
us-gaap:FairValueByMeasurementBasis
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
us-gaap:LongtermDebtType
us-gaap:LongtermDebtType
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
us-gaap:LongtermDebtType
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
us-gaap:LongtermDebtType
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingencyEstimateOfPossibleLoss
us-gaap:LossContingenciesByNatureOfContingency
dei:LegalEntity, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingencyPendingClaimsNumber
dei:LegalEntity, us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType

us-gaap:NetRegulatoryAssets
dei:LegalEntity

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeTaxAuthority
us-gaap:OperatingLossCarryforwards
us-gaap:IncomeTaxAuthority

us-gaap:OtherLongTermDebtCurrent
dei:LegalEntity

us-gaap:OtherLongTermDebtNoncurrent
dei:LegalEntity

us-gaap:OtherShortTermBorrowings
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:PostemploymentBenefitsLiabilityNoncurrent
us-gaap:BalanceSheetLocation

us-gaap:PreferredStockLiquidationPreferenceValue
us-gaap:StatementClassOfStock
cnp:PreferredStockRedemptionPeriod
us-gaap:PreferredStockRedemptionPricePerShare
us-gaap:StatementClassOfStock
us-gaap:PreferredStockSharesOutstanding
us-gaap:StatementClassOfStock, us-gaap:SubsequentEventType
us-gaap:StatementEquityComponents

us-gaap:PreferredStockValue
us-gaap:StatementClassOfStock
dei:LegalEntity
us-gaap:PublicUtilitiesInventory

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

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

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

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

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

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

us-gaap:PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:CreditFacility
us-gaap:RatioOfIndebtednessToNetCapital1
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:CreditFacility

us-gaap:RegulatoryAssets
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:IncomeStatementLocation, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:RegulatoryAssetsCurrent
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:BalanceSheetLocation
us-gaap:RegulatoryAsset

us-gaap:RegulatoryAssetsNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:IncomeStatementLocation, us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:ConsolidatedEntities
us-gaap:IncomeStatementLocation, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset

us-gaap:RegulatoryLiabilities
dei:LegalEntity
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:RegulatoryLiabilityCurrent
us-gaap:BalanceSheetLocation

us-gaap:RegulatoryLiabilityNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryLiability
us-gaap:RegulatoryLiability
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:RemainingAmountsOfRegulatoryAssetsForWhichNoReturnOnInvestmentDuringRecoveryPeriodIsProvided
us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:RestrictedCashAndCashEquivalents
us-gaap:BalanceSheetLocation

us-gaap:RevenueRemainingPerformanceObligation
us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:SecuredDebt

us-gaap:SecuritizedRegulatoryTransitionAssetsNoncurrent
dei:LegalEntity
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
dei:LegalEntity
us-gaap:SharePrice
us-gaap:AwardType
us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested

us-gaap:ShortTermBorrowings
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeTaxAuthority
us-gaap:TaxCreditCarryforwardAmount
us-gaap:IncomeTaxAuthority

us-gaap:UnamortizedLossReacquiredDebtNoncurrent
dei:LegalEntity

us-gaap:UnbilledContractsReceivable
dei:LegalEntity

us-gaap:UnbilledReceivablesCurrent
dei:LegalEntity
us-gaap:BusinessAcquisition
us-gaap:UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued

Plots across concepts


IncomeStatement
Comprehensive Income Net Of Tax
Expenses
Income Tax Expense Benefit
Balance Sheet
Operating Lease Right Of Use Asset
Assets
Operating Lease Right Of Use Asset
Current Assets
Cash And Cash Equivalents At Carrying Value
NonCurrent Assets
Operating Lease Right Of Use Asset
PropertyPlantAndEquipmentNet
Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
Liabilities
Liabilities Current
Current Liabilities
Contract With Customer Liability Current
Noncurrent Liabilities
Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent
Stockholders Equity
Retained Earnings Accumulated Deficit
Per Share
Common Stock Dividends Per Share Declared
CashFlow
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInOperatingActivities
Increase Decrease In Accounts Payable
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
NonoperatingIncomeExpense
Nonoperating Income Expense
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Payments Due Year Four
FiniteLivedIntangibleAssets
Finite Lived Intangible Assets Accumulated Amortization
AccountsReceivable
Allowance For Doubtful Accounts Receivable Current

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:CommonStockValue ███▄▄▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁6.06.06.05.05.05.05.05.05.05.05.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.0NANANANANANANA
 us-gaap:PreferredStockParOrStatedValuePerShare us-gaap:StatementClassOfStock us-gaap:SeriesAPreferredStockNA1e-081e-081e-081e-081e-081e-081e-081e-081e-081e-081e-08NANA0.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PreferredStockParOrStatedValuePerShare us-gaap:StatementClassOfStock us-gaap:SeriesBPreferredStockNA1e-081e-081e-081e-081e-081e-081e-081e-081e-081e-08NANANA0.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock█▆▆▆▆▄▄▄▄▄▄▁▁▁▁593.0552.0551.0545.0545.0502.0502.0502.0502.0502.0501.0431.0431.0431.0431.0NANANA431.0NANANA430.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding ▁█596.0631.0NA548.0531.0502.0NA505.0505.0503.944NA434.891431.523434.008NA434.086433.797433.348NA433.396430.653432.594NA430.262431.733431.183NA431.573431.409430.559NA430.867430.554429.672NA429.983429.629428.492NA428.842428.284427.415NA424.968401.993395.078NANANANA
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁586.0552.0NA545.0528.0502.0NA502.0502.0501.521NA431.554431.523431.231NA431.026430.996430.794NA430.682430.653430.407NA430.262430.235429.955NA429.796429.773429.163NA428.628428.571427.961NA427.406427.349426.499NA425.885425.638425.018NA422.178399.515392.855NANANANA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:StatementClassOfStock us-gaap:SeriesBPreferredStock35.898NANA35.9435.9435.923NA33.53732.12134.354NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:StatementClassOfStock us-gaap:SeriesCPreferredStockNANANA47.35529.465NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:EarningsPerShareBasic ▅▅▅▄▄▁▄▅▅▄▄▅▄▅█▅▅▅▄▅▄▅▃▃▄▅▅▅▄▅▄▅▄▅▅▄▅▅▄▇▄▅▅▅▄▅▄▅▄▄0.380.560.310000000000000050.130.11-2.440.250.480.330.280.180.35-0.170.383.010.390.310.450.230.42-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.280.280.350.290.290.20.290.270.310.240.19
us-gaap:EarningsPerShareDiluted ▅▅▅▄▄▁▄▅▅▅▄▅▄▅█▅▅▅▄▅▄▅▃▃▄▅▅▅▄▅▄▅▄▅▅▄▅▅▄▇▅▅▅▅▄▅▄▅▄▄0.370.560.310000000000000050.130.11-2.440.250.470.330.280.180.35-0.170.382.990.390.310.440.230.41-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.270.280.350.290.290.20.290.270.310.240.19
us-gaap:IncomeLossFromContinuingOperationsPerBasicShare ██▇▇▇▁▇█▇▇3.8e-075.6e-073.0000000000000004e-071.4e-071.7000000000000001e-07-2.1499999999999997e-062.1000000000000008e-074.4e-072.4e-072.3000000000000002e-07NANANANANANANANANANANANANANANANANANANANANANANANA3.1999999999999995e-072e-08NANA2.7e-079.000000000000001e-072.8e-073.5e-07NANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare ██▇▇▇▁▇█▇▇3.7e-075.6e-073.0000000000000004e-071.4e-071.7000000000000001e-07-2.1499999999999997e-062.1000000000000008e-074.4e-072.4e-072.3000000000000002e-07NANANANANANANANANANANANANANANANANANANANANANANANA3.0999999999999994e-072e-08NANA2.7e-079.000000000000001e-072.8e-073.5e-07NANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
 COGS Ratio dei:LegalEntity cnp:CercCorp▂▄▂▁▁▃▆▃▄██▄▄█▆▄574.01177.0843.0426.0483.01011.01734.01126.01342.02368.02303.01312.01328.02400.01872.01251.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio dei:LegalEntity cnp:EnableMidstreamPartnersNA970.0NANANA648.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners787.0NA704.0596.0515.0NA731.0699.0735.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio dei:LegalEntity cnp:CercCorp▂▄▂▁▁▃▆▃▄██▄▄█▆▄▄574.01177.0843.0426.0483.01011.01734.01126.01342.02368.02303.01312.01328.02400.01872.01251.01387.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Cost Ratio dei:LegalEntity cnp:HoustonElectric▅▂▄▆▃▁▂▇▄▂▄█▇▄▄▇▄786.0684.0729.0828.0720.0634.0680.0859.0765.0686.0728.0897.0854.0755.0765.0843.0752.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 EBT Margin dei:LegalEntity cnp:CercCorp▂▄▂▁▁▃▆▃▄██▄▄█▆▄▄574.01177.0843.0426.0483.01011.01734.01126.01342.02368.02303.01312.01328.02400.01872.01251.01387.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 EBT Margin dei:LegalEntity cnp:HoustonElectric▅▂▄▆▃▁▂▇▄▂▄█▇▄▄▇▄786.0684.0729.0828.0720.0634.0680.0859.0765.0686.0728.0897.0854.0755.0765.0843.0752.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations dei:LegalEntity cnp:CercCorpNANANA426.0483.01011.0NA1126.01342.02368.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations dei:LegalEntity,us-gaap:StatementBusinessSegments cnp:CercCorp,cnp:NaturalGasDistributionNANANA422.0480.01008.0NA389.0503.01185.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,cnp:ElectricSegment█▁937.0830.0NANA848.0767.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,cnp:NaturalGasSegment▁█740.01663.0NANA644.01321.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:StatementBusinessSegments cnp:ElectricTransmissionDistributionNANANA828.0720.0638.0NA859.0765.0689.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:StatementBusinessSegments cnp:IndianaElectricIntegratedNANANA157.0128.0129.0NA165.0140.083.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Margin from Continuing Operations us-gaap:StatementBusinessSegments cnp:NaturalGasDistributionNANANA560.0641.01318.0NA515.0650.01389.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Operating Margin dei:LegalEntity cnp:CercCorp▂▄▂▁▁▃▆▃▄██▄▄█▆▄▄574.01177.0843.0426.0483.01011.01734.01126.01342.02368.02303.01312.01328.02400.01872.01251.01387.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Operating Margin dei:LegalEntity cnp:EnableMidstreamPartnersNA970.0NANANA648.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Operating Margin dei:LegalEntity cnp:HoustonElectric▅▂▄▆▃▁▂▇▄▂▄█▇▄▄▇▄▁786.0684.0729.0828.0720.0634.0680.0859.0765.0686.0728.0897.0854.0755.0765.0843.0752.0638.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Operating Margin us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners787.0NANA596.0515.0NANA699.0735.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
 TTM Greenblatt ROC _ _▅█▅▅▄▃▅▇▅▄▃▄▃▄▅▅▄▅▄▅▃▄▄▄▃▄▄▄▃▅▃▄▄▆▅▁▅▆▅▆▅▆▅▆▄▆▅296.0453.0285.0302.0235.0217.0302.0392.0287.0245.0167.0226.0187.0251.0296.0279.0223.0274.0243.0284.0182.0250.0226.0265.0186.0256.0221.0233.0186.0295.0211.0244.0223.0332.0310.088.0302.0338.0274.0357.0303.0364.0302.0327.0263.0357.0299.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:ComprehensiveIncomeNetOfTax ▅▅▅▅▅▁▅▅▅▅▅▅▄▅█▅▅▅▅▅▄▅▃▃▅▅▅▅▅▅▅▅▄▅▅▄▅▅▅▇▅▅▅▅▅▅223.0337.0143.071.075.0-1230.049.0268.0197.0170.050.0162.0-74.0170.01300.0167.0136.0192.094.0182.0-4.0155.0-494.0-390.079.0133.0175.0145.0109.0186.0150.0154.0-98.0150.0124.013.0129.0149.094.0975.0122.0150.0123.0126.083.0117.0NANANANA
us-gaap:CostOfGoodsAndServicesSold ▁▁▁▁▁▁▆▅▅▇█▅▅▇▆▅58.040.061.063.069.064.01016.0852.0910.01251.01437.0864.0790.01273.0942.0832.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostOfRevenue dei:LegalEntity cnp:EnableMidstreamPartnersNA519.0NANANA226.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostOfRevenue us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners426.0NA312.0250.0177.0NA321.0263.0317.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:CostsAndExpenses ▁▄▃▁▁▃▇▅▅█▇▃▃▇▅▃▃▅▃▂▁▂▂▁▁▄▄▂▂▇▃▁1446.02094.01769.01320.01340.01950.02928.02350.02511.03286.02869.01986.01999.02904.02342.01819.01920.02461.01838.01605.01392.01734.01565.01365.01346.02177.02151.01574.01698.02868.01973.01396.0NANANANANANANANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperations ▇█▇▇▇▁▇▇▇▇251.0363.0200.0127.0135.0-1053.0137.0251.0151.0143.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▇▇▇▆▇▁▇▇▇▇▇▇▆▇▇▇▇▇▆▇▆▇▃▄▆▇▇▇▇▇▇▇▆▇▇▆▇▇▆█▇▇▇▇248.0437.0254.0117.0164.0-1400.0182.0332.0224.0191.0181.0209.0-88.0212.0286.0267.0211.0299.0162.0276.08.0240.0-818.0-635.0114.0209.0209.0213.0169.0294.0175.0229.0144.0233.0210.0128.0200.0219.0159.0590.0190.0235.0164.0199.0NANANANANANA
us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest ▁█251.0363.0NA127.0135.0-1053.0NA251.0151.0143.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeTaxExpenseBenefit ▇▇▇▇▇▅▇▇▇▇▇▇▇▇▁▇▇▇▇▇▇▇▅▅▇▇▇▇▇▇▇▇█▇▇▇▇▇▇█▇▇▇▇▇▇-3.074.054.0-10.029.0-347.025.062.029.022.061.051.0-13.047.0-1010.098.076.0107.061.097.010.086.0-309.0-244.037.078.033.070.062.0109.062.078.0244.086.076.0118.074.072.042.0204.071.087.040.076.045.0102.0NANANANA
 us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity cnp:CercCorp▆▇█▇▇▇▇▇▇▇▇▇▇▇▁▇▇-18.042.075.0-9.0-4.035.0-11.0-1.00.026.08.0-2.010.020.0-334.0-1.029.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity cnp:HoustonElectric▆▆▆▆▆▆▆▇▆▆▆▇▆▆▁█▇18.08.06.026.016.05.010.041.023.06.011.036.027.015.0-132.071.042.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeTaxesPaidNet ▅▅▅▇▅▅▄▅█▅▅▅▇▅▅▅▅▅▅▅▅▁▃▆▇▁▅▅█▅▄▅▆▅▅▅▆▄▅▅▄▁▅▆█▄17.0-4.026.0113.04.00.0-19.032.0146.0-4.00.01.092.0-4.01.03.013.0-2.01.021.032.0-158.0-57.050.0128.0-166.035.017.0141.0-1.0-42.010.070.0-3.00.07.047.0-8.0-1.02.0-46.0-160.0-3.066.0152.0-8.0NANANANA
us-gaap:InterestAndDebtExpense ▆▅▅▆▇██▇▇▆▄▂▃▁▁▁▁▁▂▂▂▂▂▂▂▂▃▂▂▂▂▂▂▃▄▄▄▅▅▅▅▅▆▆▆▆119.0113.0113.0121.0128.0139.0139.0134.0134.0121.0102.090.091.078.078.080.077.078.082.083.086.087.086.088.089.089.092.088.089.084.082.086.085.098.0104.0104.0104.0110.0115.0114.0111.0116.0117.0121.0121.0122.0NANANANA
us-gaap:InterestPaidNet ▃▆▅▄▁▅▂▅▂▅▂▅▁▄▂▄▂▄▂▄▃▄▃▄▃▄▃▅▂▄▂▅▃▅▄▇▂▇▃▇▃▇▃█▃▇102.0159.0147.0128.048.0148.072.0133.077.0154.062.0134.051.0116.072.0124.070.0112.082.0124.087.0113.0103.0114.094.0115.096.0135.081.0122.081.0147.0100.0147.0110.0187.081.0178.095.0194.090.0186.0104.0213.0101.0191.0NANANANA
us-gaap:NetIncomeLoss ▅▅▅▅▅▁▅▅▅▅▅▅▄▅█▅▅▅▅▅▄▅▃▃▅▅▅▅▅▅▅▅▄▅▅▄▅▅▅▇▅▅▅▅▅▅▅▅▅▅251.0363.0200.0121.0105.0-1199.0157.0270.0195.0169.0120.0158.0-75.0165.01296.0169.0135.0192.0101.0179.0-2.0154.0-509.0-391.077.0131.0176.0143.0107.0185.0113.0151.0-100.0147.0134.010.0126.0147.0117.0973.0119.0148.0124.0123.081.0114.0105.0114.086.067.0
us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic ▅▅▅▅▅▁▅▅▅▅▅▅▄▅█▅▅▅221.0334.0151.069.059.0-1228.0128.0241.0165.0140.090.0153.0-75.0165.01296.0169.0135.0192.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted ▁█221.0351.0NANA59.0-1228.0128.0241.0165.0140.090.0153.0-75.0165.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NonoperatingIncomeExpense ▇▇▇▆▇▁▇▇▇▇▇▇▆▇▇▇▇▇▇▇▆▇▃▄▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇█▇▇▇▇▇▇-48.0-16.0-31.0-185.0-71.0-1617.0-120.0-60.0-63.0-54.014.0-17.0-275.0-39.0-10.0-12.0-12.025.0-81.0-8.0-174.0-10.0-1044.0-900.0-72.0-47.0-12.0-20.0-17.0-1.0-36.0-15.0-79.0-99.0-100.040.0-102.0-119.0-115.0233.0-113.0-129.0-138.0-128.0-137.0-141.0NANANANA
 us-gaap:NonoperatingIncomeExpense dei:LegalEntity cnp:CercCorp▃▃▃▂▂▂▂▂▂▂▂▂█▂▁▂█-24.0-25.0-26.0-29.0-29.0-34.0-31.0-31.0-30.0-32.0-33.0-30.024.0-33.0-43.0-36.024.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NonoperatingIncomeExpense dei:LegalEntity cnp:HoustonElectric▄▆▅▄▄▇▇█▆▅▅▅▂▂▄▂▁-49.0-46.0-47.0-49.0-49.0-44.0-45.0-43.0-46.0-48.0-47.0-48.0-53.0-52.0-49.0-53.0-54.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OperatingIncomeLoss ▅█▅▅▄▃▅▇▅▄▃▄▃▄▅▅▄▅▄▅▃▄▄▄▃▄▄▄▃▅▃▄▄▆▅▁▅▆▅▆▅▆▅▆▄▆▅▅▄▅296.0453.0285.0302.0235.0217.0302.0392.0287.0245.0167.0226.0187.0251.0296.0279.0223.0274.0243.0284.0182.0250.0226.0265.0186.0256.0221.0233.0186.0295.0211.0244.0223.0332.0310.088.0302.0338.0274.0357.0303.0364.0302.0327.0263.0357.0299.0287.0253.0285.0
 us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity,us-gaap:StatementEquityComponents cnp:HoustonElectric,us-gaap:AccumulatedOtherComprehensiveIncomeNANA0.00.015.00.00.00.00.0-1.0-21.03.00.04.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedOtherComprehensiveIncome▆▆▅▆█▆▇▆▆▆▁▆▆▆2.03.0-8.02.016.0-2.09.0-2.02.01.0-35.04.01.05.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherNonoperatingIncomeExpense ▄▁▅▄▆▄▄▄▄▆█▄▃▃▄▅▅▅▁▆▅▄▄▄▄▄▄▄▄▄▄▄▂▃▄▄▄▃▃▄▃▃▃▃▃▂11.0-8.016.010.021.013.010.09.011.020.034.09.04.03.010.017.016.017.0-6.020.014.07.010.012.013.011.08.010.09.09.07.011.00.06.010.012.010.06.04.010.04.05.05.03.03.01.0NANANANA
us-gaap:PreferredStockDividendsIncomeStatementImpact ▆▆█▇▇▆▆▆▆▆▆▂▁▁30.029.042.036.037.029.029.029.030.029.030.05.00.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:RegulatedOperatingRevenue ▄█▅▃▃▆▅▃▃▆▃▂▂▅▃▁▁▃▂▂▁▃1652.02484.01962.01538.01476.02073.01907.01539.01555.02161.01629.01299.01341.01894.01602.01233.01222.01546.01437.01278.01177.01548.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▂▅▄▂▂▄█▄▄▅▇▁▁▄▆▁▁▂▄▃▂▃▃▂▂▅▅▃▃█▄▂▃▅▄▂▂▄▄▃▃▆▄▃▃▇▅▂▂▆1715.02541.02033.01610.01566.02141.03230.02093.02056.02539.03036.01385.01449.02126.02638.01347.01338.01712.02081.01889.01574.01984.01791.01630.01532.02433.02372.01807.01884.03163.02184.01640.01894.02388.02138.01705.01525.02084.02145.01881.01837.02587.02098.01908.01756.03023.02299.01576.01640.02766.0
us-gaap:Revenues ▂▅▃▁▁▃▇▅▅█▆▃▃▇▅▃▃▅▃▂▁▃▂▁▁▄▄▂▂▇▃▁▂▄▃▂▁▃▃▂▂▅▃▂▂▆▄▁▁▅1742.02547.02054.01622.01575.02167.03230.02742.02798.03531.03036.02212.02186.03155.02638.02098.02143.02735.02081.01889.01574.01984.01791.01630.01532.02433.02372.01807.01884.03163.02184.01640.01894.02388.02138.01705.01525.02084.02145.01881.01837.02587.02098.01908.01756.03023.02299.01576.01640.02766.0
us-gaap:UnregulatedOperatingRevenue ▁▁▁▁▁▁█▇▇██▅▅▇▆▅▅▇▄▄▃▃90.063.092.084.099.094.01323.01203.01243.01370.01407.0913.0845.01261.01036.0865.0921.01189.0644.0611.0397.0436.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:Assets ██▇▆▆▇█▇▇▇▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁36466.035906.033471.032705.032148.033395.035439.034642.034189.033902.027009.022228.022108.022410.022736.022135.022045.021931.021829.021286.021012.021004.021334.021778.022602.022670.023200.022048.021920.022264.021870.021575.021658.022370.022871.022477.022475.022351.021703.020951.019677.019594.020111.0NANANA19773.0NANANA
us-gaap:LiabilitiesAndStockholdersEquity ██▇▆▆▇█▇▇▇▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁36466.035906.033471.032705.032148.033395.035439.034642.034189.033902.027009.022228.022108.022410.022736.022135.022045.021931.021829.021286.021012.021004.021334.021778.022602.022670.023200.022048.021920.022264.021870.021575.021658.022370.022871.022477.022475.022351.021703.020951.019677.019594.020111.0NANANA19773.0NANANA
us-gaap:StockholdersEquity ██▇▇▇▆▇▇▇▇▇▄▃▃▃▂▁▁▁▁▁▁▁▂▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁8870.08716.08348.08388.08392.06970.08359.08346.08257.08216.08058.05508.04670.04857.04688.03618.03563.03537.03460.03472.03397.03506.03461.04058.04550.04574.04548.04473.04425.04414.04329.04261.04191.04371.04301.04257.04332.04286.04222.04207.03313.03266.03198.0NANANA2639.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:AssetsCurrent ▅▃▂▂▂▄▄▃▃▃█▂▂▂▃▂▂▂▂▂▁▁▂▂▂▂▃▂▂▂▂▁▂▂▂▂▂▂▁▁▁▁▂5179.03219.02920.02785.02501.04164.03847.03416.03326.03419.07025.02726.02701.03049.03395.02935.02865.02896.02923.02529.02272.02335.02689.02400.02509.02691.03268.02576.02529.02955.02658.02319.02480.02363.02874.02752.02955.02968.02337.01982.02042.02014.02582.0NANANA2904.0NANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▁▁▁▁▁▁▁▁▁▁█▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▁▂▂▃▃▁▁▁▁▁▁▂▁▂136.0146.0147.0185.0168.0220.0241.0259.0271.0255.04231.0293.0328.0219.0260.0201.0248.0254.0341.0270.0271.0218.0264.0227.0245.0234.0298.0230.0206.0379.0208.0219.0497.0245.0646.0722.01123.01096.0220.0103.0190.095.0199.099.0583.0329.0740.0NANANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▁▁▁▁▁▁▁▁▁▁█▁▁▁▁▁▁▁▁157.0167.0167.0208.0194.0247.0271.0297.0332.0355.04278.0331.0366.0257.0296.0233.0280.0290.0381.0NANANA300.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:MarketableSecuritiesCurrent ▇▆▆▆▅▄▆▅▄▄▃▄▃▇▇██▇▇▆▅▆▆▆▇▇▇▆▆▅▅▄▄▄▃▃▂▂▁▁▂▂▁923.0848.0871.0836.0753.0678.0822.0746.0687.0623.0540.0627.0584.0944.0960.01057.01020.0997.0953.0814.0737.0894.0805.0826.0960.0913.0930.0840.0809.0737.0767.0689.0635.0614.0540.0522.0445.0432.0386.0337.0417.0399.0367.0NANANA300.0NANANA
us-gaap:AccountsReceivableNetCurrent ▂▃▂▂▂▂▇▅▆█▆▄▄▅▅▃▃▃▂▂▁▁▁▁▂▄▃▂▃▆▃▁▂▃▃▂▂▂▃▂▃▃▃651.0780.0676.0731.0735.0711.01249.01091.01173.01415.01190.0918.0958.01081.01000.0783.0762.0840.0740.0682.0605.0577.0593.0568.0640.0897.0837.0712.0834.01142.0851.0617.0694.0860.0768.0698.0643.0713.0773.0722.0750.0852.0835.0NANANA790.0NANANA
us-gaap:InventoryRawMaterialsAndSupplies ██▇▇▇▆▆▆▆▆▃▃▃▂▂▃▃▃▃▃▃▂▃▂▃▂▂▂▂▁▁▁▁▃▃▃▂▂▂▂319.0310.0297.0300.0304.0278.0269.0273.0267.0256.0200.0198.0192.0176.0175.0190.0192.0178.0181.0191.0187.0176.0179.0174.0178.0161.0168.0156.0155.0146.0145.0137.0137.0181.0177.0182.0176.0168.0166.0168.0NANA164.0NANANA138.0NANANA
us-gaap:PrepaidExpenseAndOtherAssetsCurrent ▆█▁▁▁▁▂▂▂▃▂▂▂▂▃▂▂▂▂▂▁▁▁▁▁▁▂▂▂▂▁▁▁▁▂▃▃▂▂▂483.0646.0139.0113.0108.0120.0161.0156.0181.0241.0192.0157.0167.0189.0241.0175.0167.0184.0161.0154.0135.0127.0140.0111.0105.0132.0178.0177.0173.0158.0125.0112.0116.0137.0216.0245.0253.0220.0192.0190.0NANA274.0NANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
 us-gaap:AssetsNoncurrent dei:LegalEntity cnp:EnableMidstreamPartnersNA11315.011348.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AssetsNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners11284.0NA11348.011402.011687.0NA11877.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PropertyPlantAndEquipmentGross ████▇▇▇▇▇▇▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁▃▃▃▂▂▂▂▂▂▂32004.032991.032514.031823.031349.030830.030685.030066.029552.029011.020267.019861.019585.019294.019031.018581.018374.018070.017831.017500.017218.016900.016650.016264.015967.015633.015358.014975.014674.014368.014138.013909.013623.018598.018377.018010.017350.017073.016868.016591.016426.016235.016005.0NANANA14770.0NANANA
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment ██████▇▇▇▇▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▂▂▁▁▁▁▁▁▁▁9908.010252.010152.010088.010001.09852.09740.09738.09620.09499.06223.06208.06188.06089.05974.05881.05730.05618.05524.05417.05320.05182.05113.05079.05056.04963.04856.04770.04695.04605.04545.04523.04439.04890.04780.04673.04611.04561.04466.04433.04445.04378.04273.0NANANA3982.0NANANA
us-gaap:AmortizationOfIntangibleAssets NANA1.00.00.01.05.07.03.09.03.02.02.03.08.02.01.02.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AmortizationOfIntangibleAssets us-gaap:IncomeStatementLocation cnp:Depreciationandamortizationexpense▂▁▁▂▂▁▆██▇▃▂▂▃2.01.01.02.02.01.05.07.07.06.03.02.02.03.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AmortizationOfIntangibleAssets us-gaap:IncomeStatementLocation us-gaap:CostOfSalesNANA1.00.00.01.05.07.03.07.00.00.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PropertyPlantAndEquipmentNet ███▇▇▇▇▇▇▆▄▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▁▁▁▃▃▃▃▃▃▃▂▂▂22096.022739.022362.021735.021348.020978.020945.020328.019932.019512.014044.013653.013397.013205.013057.012700.012644.012452.012307.012083.011898.011718.011537.011185.010911.010670.010502.010205.09979.09763.09593.09386.09184.013708.013597.013337.012739.012512.012402.012158.011981.011857.011732.0NANANA10788.0NANANA
us-gaap:Goodwill ▇▇▇▇▇▇████▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▂▂▂4294.04697.04697.04697.04697.04697.05164.05179.05179.05129.0867.0867.0867.0867.0867.0867.0867.0867.0862.0862.0861.0840.0840.0840.0840.0840.0840.0840.0840.0840.0840.0840.0840.01468.01468.01468.01696.01696.01696.01696.01696.01696.01696.0NANANA1696.0NANANA
us-gaap:FiniteLivedIntangibleAssetsNet ▁▁▁▁▁▁▆▆▆█▁▁▁▁▁47.049.050.052.054.056.0321.0356.0370.0460.065.067.069.071.074.0NANANA49.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OperatingLeaseRightOfUseAsset NANA31.0NANANA63.067.072.067.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity cnp:CercCorpNANA19.0NANANA24.025.026.026.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent ▆▆▇▆▆▆▅▇▇█▆▄▅▄▄▄▅▅▄▂▃▁▂▃▃▂▃▃▃▃▃▂▄▄▄▄▄▃▃▃▃▃▃225.0240.0252.0226.0235.0223.0216.0273.0273.0286.0223.0190.0216.0194.0191.0194.0207.0204.0173.0134.0147.0109.0146.0148.0151.0144.0147.0150.0161.0159.0162.0140.0187.0197.0197.0183.0193.0159.0157.0154.0158.0157.0172.0NANANA230.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:AccountsPayableCurrent ▅▅▅▄▄▄▇▅▆██▄▄▄▆▄▃▃▄▂▂▁▂▁▁▂▄▂▂▅▄▁▂▂▃▁▁▁▃▂▁▂▄797.0797.0853.0658.0670.0739.01138.0888.0936.01181.01240.0708.0706.0712.0963.0657.0631.0634.0657.0422.0407.0378.0483.0367.0367.0476.0716.0441.0519.0802.0689.0364.0404.0510.0561.0371.0331.0366.0560.0417.0394.0449.0667.0NANANA648.0NANANA
us-gaap:ContractWithCustomerLiabilityCurrent ▁▆▆▆███109.0120.0119.0120.0124.0124.0124.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DebtCurrent NANA1919.0NANANA868.0NANANA482.0NANANA645.0NANANA1060.0NANANA913.0NANANA848.0NANANA540.0NANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtCurrent dei:LegalEntity cnp:CercCorpNANA24.0NANANA0.0NANANA0.0NANANA39.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtCurrent dei:LegalEntity cnp:HoustonElectricNANA613.0NANANA231.0NANANA458.0NANANA434.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DividendsPayableCurrent NANA136.0NANANA0.00.00.00.0187.00.00.00.0120.0NANANA0.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LiabilitiesCurrent ▄▇█▅▇▆▆▄▃▄▄▂▃▂▃▄▃▂▃▂▁▂▂▄▃▄▄▃▃▃▃▂▂▃▅▄▄▂▂▁▁▁▂3369.04326.04825.03830.04309.04042.03888.03434.02996.03139.03302.02581.02842.02616.03069.03221.03038.02642.03080.02398.02241.02534.02467.03191.03125.03187.03475.03008.03026.03059.03019.02595.02675.03126.03575.03364.03206.02735.02593.02319.02361.02201.02620.0NANANA3038.0NANANA
 us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity cnp:CercCorpNANA3.0NANANA4.04.05.04.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:OperatingLeaseLiabilityCurrent us-gaap:BalanceSheetLocation us-gaap:OtherCurrentLiabilitiesNANA6.0NANANA7.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesCurrent ▄▄██▃▂▇▅▄▄▄▆▄▄▅▄▁▁▃▅▄▃▄▆▆▆▆▅▅▅▇▄▅▄▆▄▃▂▅▃▃▄█336.0344.0432.0429.0325.0300.0414.0375.0343.0338.0341.0392.0344.0343.0368.0339.0269.0267.0325.0353.0334.0317.0343.0384.0385.0394.0383.0373.0355.0365.0402.0343.0358.0347.0380.0347.0327.0281.0366.0319.0322.0350.0438.0NANANA445.0NANANA
us-gaap:TaxesPayableCurrent ▆▇█▆▇▄▇▅▄▆▆▃▂▄▅▅▄▂▄▃▁▁▄▃▁▃▄▃▃▆▅▃▁▂▄▄▃▄▆▅▃▃▄203.0229.0265.0212.0241.0177.0241.0193.0158.0214.0204.0152.0103.0176.0181.0199.0153.0108.0172.0134.092.0101.0158.0128.090.0142.0161.0139.0129.0220.0184.0130.095.0123.0160.0171.0132.0164.0207.0184.0139.0140.0156.0NANANA148.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
 us-gaap:LiabilitiesNoncurrent dei:LegalEntity cnp:EnableMidstreamPartnersNA3249.04052.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LiabilitiesNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners3249.0NA4052.04055.04454.0NA4077.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LongTermDebt NANA11521.0NANANA14244.0NANANA8682.0NANANA8195.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt dei:LegalEntity cnp:CercCorpNANA2428.0NANANA2546.0NANANA2371.0NANANA2457.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt dei:LegalEntity cnp:HoustonElectricNANA4406.0NANANA4719.0NANANA4258.0NANANA4319.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LongTermDebtNoncurrent █▇▄▅▄▆▇▇▇▆▂▁▁▂▂▁▁▂▁▁▁▁▂▁▁▁▂▁▁▂▁▁▂▂▂▂▂▂▂▂▂▂▂15853.014048.011521.011946.010937.013830.014244.014014.014121.013759.08682.07252.07760.08176.08195.07531.07587.07892.07532.07736.07780.07354.07901.07662.07614.07767.08009.07797.07755.08056.07817.07758.07919.08130.08357.08415.08583.09005.08641.08497.08510.08732.09001.0NANANA9119.0NANANA
 us-gaap:DeferredFinanceCostsNoncurrentNet dei:LegalEntity,us-gaap:LongtermDebtType cnp:HoustonElectric,cnp:UnamortizedDebtIssuanceCostsNANA28.0NANANA27.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DeferredFinanceCostsNoncurrentNet us-gaap:LongtermDebtType cnp:UnamortizedDebtIssuanceCostsNANA17.0NANANA22.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DeferredIncomeTaxLiabilitiesNet ▄▄▃▂▁▂█3698.03687.03603.03575.03491.03562.03928.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▁▁▁▁▃▂▂▃▄▄▃▂▂▂▃▄▅▅▅▅▄▅▄▄▅▅▅▂▃▃▃▇▇██▆▆▇▇▄▄▅▅665.0675.0680.0691.0771.0746.0754.0812.0872.0888.0796.0722.0723.0723.0785.0886.0908.0916.0913.0909.0904.0909.0904.0889.0925.0928.0953.0718.0773.0802.0802.01052.01102.01137.01143.0994.01020.01066.01065.0842.0903.0905.0906.0NANANA861.0NANANA
 us-gaap:MinorityInterest us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners25.0NA26.026.027.0NA37.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesNoncurrent ▇██▆▆▆▆▅▅▄▃▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▂▂▁▂▁▃▃▃946.01033.01019.0789.0774.0751.0763.0672.0653.0609.0402.0433.0412.0361.0357.0284.0292.0287.0278.0282.0279.0276.0273.0259.0250.0253.0251.0207.0206.0203.0205.0251.0232.0258.0247.0276.0263.0239.0305.0236.0407.0473.0438.0NANANA361.0NANANA
 us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity cnp:CercCorpNANA18.0NANANA20.021.021.022.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:OperatingLeaseLiabilityNoncurrent us-gaap:BalanceSheetLocation us-gaap:OtherNoncurrentLiabilitiesNANA26.0NANANA24.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA6.0NANANA16.015.015.012.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo dei:LegalEntity cnp:CercCorpNANA4.0NANANA4.05.04.04.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA6.0NANANA9.09.08.07.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA4.0NANANA7.07.07.06.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA10.0NANANA12.012.012.09.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive dei:LegalEntity cnp:CercCorpNANA7.0NANANA9.09.09.09.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:StockholdersEquity ██▇▇▇▆▇▇▇▇▇▄▃▃▃▂▁▁▁▁▁▁▁▂▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁8870.08716.08348.08388.08392.06970.08359.08346.08257.08216.08058.05508.04670.04857.04688.03618.03563.03537.03460.03472.03397.03506.03461.04058.04550.04574.04548.04473.04425.04414.04329.04261.04191.04371.04301.04257.04332.04286.04222.04207.03313.03266.03198.0NANANA2639.0NANANA
us-gaap:CommonStockValue ███▄▄▄▄▄▄▄▄▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁6.06.06.05.05.05.05.05.05.05.05.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.04.0NANANANANANANA
us-gaap:AdditionalPaidInCapital █▇▇▆▆▅▅▅▅▅▅▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁7553.06916.06914.06805.06801.06086.06080.06072.06065.06060.06072.04221.04215.04208.04209.04204.04200.04195.04195.04190.04186.04180.04180.04176.04172.04168.04169.04167.04162.04158.04157.04151.04146.04139.04130.04123.04125.04122.04120.04114.04111.04102.04100.0NANANANANANANA
us-gaap:RetainedEarningsAccumulatedDeficit ▃▃▁▁▁▁██▇▇▆▇▇█▇▂▂▂▂▂▂▂▂▅▇▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▂▂▁-343.0-482.0-845.0-796.0-771.0-761.0632.0636.0552.0518.0349.0551.0513.0708.0543.0-518.0-571.0-591.0-668.0-658.0-726.0-613.0-657.0-41.0456.0486.0461.0387.0346.0341.0258.0233.0171.0360.0302.0255.0331.0291.0231.0199.0-690.0-725.0-789.0NANANANANANANA
 us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity cnp:CercCorp█▇▃▃▃▄▃▂▂▄▁▂▃720.0662.0511.0506.0518.0545.0515.0463.0486.0541.0423.0463.0529.0NA574.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity cnp:HoustonElectric▄▃▃▃▂▁▅█▇▅▅▆▅719.0616.0563.0600.0495.0428.0780.01012.0887.0803.0800.0846.0763.0NA673.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▆▅▅▆▆▄▄▄▄▄▃███▇▇▇▇▇▇▇▇▇▆▆▆▅▆▅▅▅▂▁▁▁▂▂▁▁▃▃▃▃-85.0-87.0-90.0-82.0-84.0-100.0-98.0-107.0-105.0-107.0-108.0-58.0-62.0-63.0-68.0-72.0-70.0-71.0-71.0-64.0-67.0-65.0-66.0-81.0-82.0-84.0-86.0-85.0-87.0-89.0-90.0-127.0-130.0-132.0-135.0-125.0-128.0-131.0-133.0-110.0-112.0-115.0-117.0NANANANANANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity cnp:CercCorp███████▁▁▁▁▂▂10.010.010.010.010.010.010.05.05.05.05.06.06.0NA6.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:MinorityInterest us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName cnp:EnableMidstreamPartners25.0NA26.026.027.0NA37.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital624.0NANA-1.0673.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:PreferredStockNANANA15.0701.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities █▁█▇████▇▇▇██▇▇▇▇▇605.0-1681.0556.0258.0519.0662.0552.0512.0303.0271.0457.0586.0609.0484.0393.0351.0360.0317.0NANANANANANANANANANANANANANA257.0533.0481.0452.0503.0424.0439.0312.0510.0627.0403.0165.0383.0435.0NANANANA
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▇▇█▇▇▇▇▁▇▇█▇▇▇▇▇-772.0-604.0-582.0-540.0511.0-654.0-646.0-626.0-610.0-6539.0-533.0-407.064.0-331.0-360.0-257.0-268.0-372.0NANANANANANANANANANANANANANA-351.0-274.0-394.0-552.0-365.0-292.0-358.0-276.0-264.0-308.0-406.0-295.0-416.0-303.0NANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cnp:CercCorp▄▄▅▃█▄▄▄▄▂▁▄▅▅▆▅-184.0-131.0-113.0-242.080.0-177.0-147.0-129.0-136.0-250.0-338.0-162.0-100.0-97.0-66.0-75.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cnp:HoustonElectric█▂▆▆▆█▇▆▇▁▆▆▇▅▆▆145.0-982.0-281.0-176.0-299.0192.09.0-193.0-74.0-1237.0-248.0-195.0-104.0-364.0-207.0-151.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▃▆▂▃▁▂▃▃▃▆█▂▂▂▃▂▂▂157.02285.0-15.0296.0-1083.0-32.068.079.0284.02345.04023.0-214.0-564.0-192.034.0-141.0-102.0-36.0NANANANANANANANANANANANANANA346.0-660.0-163.0-301.0-111.0744.036.0-123.0-151.0-423.0103.0-354.0287.0-543.0NANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:AmortizationOfFinancingCosts ▃▂▁▃▃▂▂▃▂▂▇█▅▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▄▃▂▃▃▂▃▂▂▂▂▂8.07.05.08.08.07.07.08.07.07.014.016.012.06.06.06.06.06.07.06.07.06.06.07.07.07.07.07.07.07.07.07.08.08.09.08.07.08.08.07.08.07.06.07.07.07.0NANANANA
us-gaap:DeferredIncomeTaxExpenseBenefit ▇▇▇▇▆▅▇▇▇▇▇▇▇▇▁▇▇▇▇▇▇▇▆▅▇▇█▇▇▇▇▇█▇▇▇▇▇▇██▇▇█▇▇-15.066.00.048.0-100.0-377.061.029.0-7.0-14.015.045.05.0-17.0-955.090.010.085.063.081.04.065.0-149.0-268.0-3.07.0186.081.09.04.00.099.0200.057.091.0109.064.064.039.0195.0129.080.087.0149.0-3.0-34.0NANANANA
 us-gaap:DeferredIncomeTaxExpenseBenefit dei:LegalEntity cnp:CercCorp▆▇█▆▇▇▆▇▇▇▇▆▇▇▁▆-17.041.072.0-7.03.023.0-19.06.0-1.021.025.0-35.027.014.0-293.0-46.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DeferredIncomeTaxExpenseBenefit dei:LegalEntity cnp:HoustonElectric▇▇▇▆▇▇█▇▇▇▇█▆▆▁█2.0-5.0-6.0-26.0-9.0-1.015.0-12.0-12.0-15.0-14.014.0-18.0-20.0-127.06.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:DepreciationDepletionAndAmortization ▇▆▆▆▆▅▆██▆▄▇█▆▅▄▃▂▃▇▅▄▃▄▂▁▂▅▃▂▁▃▃▂▃▆▄▂327.0307.0304.0306.0297.0282.0300.0334.0340.0313.0261.0326.0342.0314.0287.0269.0254.0226.0253.0324.0289.0260.0246.0268.0239.0217.0229.0293.0256.0235.0213.0248.0253.0240.0250.0301.0275.0224.0NANANANANANANANANANANANA
us-gaap:IncreaseDecreaseInAccountsPayable ▃▃▆▄▄▂▅▃▂▁█▄▄▂▆▄▄▃▆▄▄▃▅▄▃▂▆▃▁▅▆▃▃▄▅▄▃▂▅▄▃▂▆▃▃▃-65.0-55.0253.0-30.0-29.0-192.0191.0-52.0-262.0-332.0482.0-16.0-37.0-209.0273.021.0-36.0-122.0223.019.0-27.0-82.0108.0-5.0-119.0-208.0234.0-63.0-302.0128.0303.0-43.0-75.0-33.0180.031.0-45.0-172.0134.05.0-52.0-168.0249.0-68.0-90.0-125.0NANANANA
 us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity cnp:CercCorp▃▄▅▄▃▂▅▃▂▁█▃▃▂▇▃-66.0-10.0108.03.0-24.0-159.0153.0-16.0-187.0-255.0424.0-13.0-75.0-173.0291.0-24.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity cnp:HoustonElectric▇▅▇▃▅▄▅▄▄▅▅▄▅▃▁█35.014.035.0-16.011.0-2.010.01.00.02.05.00.010.0-16.0-46.048.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncreaseDecreaseInInventories ▆▃▄▇▇▃▄▇▇▂▅▆▇▂▄▆▇▃▄▆▆▃▅▇▇▁▄██▂▃▇█▂▄▇▅▃▄██▁▂▇█▁46.0-99.0-59.072.088.0-110.0-33.095.0110.0-120.0-11.062.087.0-139.0-45.032.094.0-74.0-39.068.049.0-112.05.070.076.0-179.0-24.0116.0123.0-113.0-89.099.0131.0-119.0-30.083.014.0-94.0-61.0116.0115.0-181.0-137.0107.0137.0-161.0NANANANA
us-gaap:NetCashProvidedByUsedInOperatingActivities █▁█▇████▇▇▇██▇▇▇▇▇605.0-1681.0556.0258.0519.0662.0552.0512.0303.0271.0457.0586.0609.0484.0393.0351.0360.0317.0NANANANANANANANANANANANANANA257.0533.0481.0452.0503.0424.0439.0312.0510.0627.0403.0165.0383.0435.0NANANANA
us-gaap:NetIncomeLoss ▅▅▅▅▅▁▅▅▅▅▅▅▄▅█▅▅▅▅▅▄▅▃▃▅▅▅▅▅▅▅▅▄▅▅▄▅▅▅▇▅▅▅▅▅▅▅▅▅▅251.0363.0200.0121.0105.0-1199.0157.0270.0195.0169.0120.0158.0-75.0165.01296.0169.0135.0192.0101.0179.0-2.0154.0-509.0-391.077.0131.0176.0143.0107.0185.0113.0151.0-100.0147.0134.010.0126.0147.0117.0973.0119.0148.0124.0123.081.0114.0105.0114.086.067.0
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▇▇█▇▇▇▇▁▇▇█▇▇▇▇▇-772.0-604.0-582.0-540.0511.0-654.0-646.0-626.0-610.0-6539.0-533.0-407.064.0-331.0-360.0-257.0-268.0-372.0NANANANANANANANANANANANANANA-351.0-274.0-394.0-552.0-365.0-292.0-358.0-276.0-264.0-308.0-406.0-295.0-416.0-303.0NANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cnp:CercCorp▄▄▅▃█▄▄▄▄▂▁▄▅▅▆▅-184.0-131.0-113.0-242.080.0-177.0-147.0-129.0-136.0-250.0-338.0-162.0-100.0-97.0-66.0-75.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity cnp:HoustonElectric█▂▆▆▆█▇▆▇▁▆▆▇▅▆▆145.0-982.0-281.0-176.0-299.0192.09.0-193.0-74.0-1237.0-248.0-195.0-104.0-364.0-207.0-151.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PaymentsToAcquireProductiveAssets █████████▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▁▇▇▇789.0594.0707.0611.0614.0664.0684.0653.0632.0537.0530.0424.0335.0362.0432.0345.0337.0312.0367.0365.0350.0332.0453.0419.0371.0341.0374.0373.0324.0301.0374.0326.0315.0271.0394.0294.0260.0264.0343.0327.0300.0333.0-2562.0326.0469.0258.0NANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▃▆▂▃▁▂▃▃▃▆█▂▂▂▃▂▂▂157.02285.0-15.0296.0-1083.0-32.068.079.0284.02345.04023.0-214.0-564.0-192.034.0-141.0-102.0-36.0NANANANANANANANANANANANANANA346.0-660.0-163.0-301.0-111.0744.036.0-123.0-151.0-423.0103.0-354.0287.0-543.0NANANANA
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▅█▂▁▂▁▁▄▄▃▅▁▁▃▁▃▁▂▁▂▂▁▁▁▁▁▁▁▁▃▁▁▄▁▁▃▁▅▁▁▁▂▁▁▁▁1698.02795.0500.00.0299.00.00.01195.01000.0721.01498.00.00.0997.00.0798.00.0298.00.0300.0300.00.00.00.00.00.00.00.00.0600.00.00.01050.00.00.0800.00.01695.00.00.00.0550.00.00.00.00.0NANANANA
us-gaap:RepaymentsOfLongTermDebt █▃▄▁▅▁▁▂▁▅▂▂▁▂▄▂▁▃▃▂▄▂▂▂▂▂▁▁▂▂▂▂▄▄▁▅▁▃▁▂▁▄▁▂▁▃1572.0388.0664.028.0969.063.077.0148.083.0994.0116.0138.065.0165.0614.0128.064.0405.0363.0120.0588.0147.0131.0113.0261.0139.060.0104.0142.0231.0118.0260.0583.0612.062.0956.046.0526.00.0143.00.0766.00.0335.07.0441.0NANANANA
 us-gaap:PaymentsOfDividends dei:LegalEntity cnp:CercCorpNANA0.08.040.032.01.016.083.020.074.075.0125.086.0264.089.0140.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PaymentsOfDividends dei:LegalEntity cnp:HoustonElectricNANA94.052.020.0385.0276.060.016.024.086.060.031.032.093.045.010.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PaymentsOfDividendsCommonStock ▃▂▂▂▂█████▇▅▅▅▅▅▅▅▄▄▄▄▄▄▄▄▄▄▄▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁95.088.083.082.082.0145.0144.0145.0144.0144.0139.0120.0120.0120.0115.0116.0115.0115.0111.0111.0111.0110.0107.0106.0107.0106.0102.0102.0102.0102.088.089.089.089.087.086.086.087.085.084.084.084.083.082.077.077.0NANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value6000000.06000000.06000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Preferred Stock Par Or Stated Value Per Share

us-gaap:PreferredStockParOrStatedValuePerShare us-gaap:StatementClassOfStock

us-gaap:PreferredStockParOrStatedValuePerShare

us-gaap:SeriesAPreferredStock


Preferred
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-08-222017-12-31
Value0.010.010.010.010.010.010.010.010.010.010.011000.00
Percentage of PreferredStockParOrStatedValuePerShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:SeriesBPreferredStock


Preferred
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value0.010.010.010.010.010.010.010.010.010.010
Percentage of PreferredStockParOrStatedValuePerShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents

us-gaap:CommonStockSharesOutstanding

us-gaap:CommonStock


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value593552551545545502502502502502501431431431431431430
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value596631548531502505505503434431434434433433433430432430431431431431430430430429429429428428428427424401395
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value586552545528502502502501431431431431430430430430430430430429429429429428428427427427426425425425422399392
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:StatementClassOfStock

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:SeriesBPreferredStock


Antidilutive
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value35353535333234
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount100.0100.0100.0100.0100.0100.0100.0

us-gaap:SeriesCPreferredStock


Antidilutive
Period End2020-09-302020-06-30
Value4729
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount131.882.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value0.380.560.310.130.11-2.440.250.480.330.280.180.35-0.170.383.010.390.310.450.230.42-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.280.280.350.290.290.20.290.270.310.240.19
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value0.370.560.310.130.11-2.440.250.470.330.280.180.35-0.170.382.990.390.310.440.230.41-0.010.36-1.18-0.910.180.30.410.330.250.430.260.35-0.230.340.310.020.290.340.272.270.280.350.290.290.20.290.270.310.240.19
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Basic Share

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312012-12-312012-09-302011-12-312011-09-302011-06-302011-03-31
Value0.380.560.30.140.17-2.150.210.440.240.230.320.020.270.90.280.35
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Diluted Share

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312012-12-312012-09-302011-12-312011-09-302011-06-302011-03-31
Value0.370.560.30.140.17-2.150.210.440.240.230.310.020.270.90.280.35
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2233371437175-1230.04926819717050162-74.0170130016713619294182-4.0155-494.0-390.079133175145109186150154-98.0150124131291499497512215012312683117
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.013.30.04.44.8-57.41.512.89.66.71.611.7-5.18.049.312.410.211.24.59.6-0.37.8-27.6-23.95.25.57.48.05.85.96.99.4-5.26.35.80.88.57.14.451.86.65.85.96.64.73.9

us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity

cnp:CercCorp


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value581515.0-4.0136758-7.028138339.0361305093854
Percentage of ComprehensiveIncomeNetOfTax26.044.83.5-5.617.3-5.4118.4-2.614.281.266.05.6-48.676.539.222.839.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.45.90.0-0.20.83.11.8-0.31.45.41.10.62.56.119.32.84.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp10.40.00.0-1.02.86.80.0-1.54.710.10.01.96.19.50.07.79.3

cnp:HoustonElectric


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value1035357157102334418510026191461015621013075
Percentage of ComprehensiveIncomeNetOfTax46.215.739.9221.1136.0-2.789.869.050.815.338.090.1-136.532.916.277.855.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.02.10.09.86.51.51.48.84.91.00.610.57.02.68.09.75.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric13.00.00.00.014.10.00.00.00.00.00.00.00.00.00.00.00.0

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostOfGoodsAndServicesSold


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value5840616369641016852910125114378647901273942832
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.41.60.03.94.43.031.540.744.349.347.362.454.559.935.761.8

us-gaap:CostOfGoodsAndServicesSold dei:LegalEntity

cnp:CercCorp


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value10.02.02.02.07.06.0876687769117114378647901273942832
Percentage of CostOfGoodsAndServicesSold17.25.03.33.210.19.486.280.684.593.6100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.60.10.00.10.40.327.132.837.446.147.362.454.559.935.761.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp1.80.00.00.51.50.60.0144.0128.885.30.0180.0134.693.30.0168.8

Cost Of Revenue

us-gaap:CostOfRevenue dei:LegalEntity

us-gaap:CostOfRevenue

cnp:EnableMidstreamPartners


Cost
Period End2021-03-312020-03-31
Value519226
Percentage of CostOfRevenue100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax20.410.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.0

us-gaap:CostOfRevenue us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Cost
Period End2021-06-302020-12-312020-09-302020-06-302019-12-312019-09-302019-06-30
Value426312250177321263317
Percentage of CostOfRevenue0.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax24.80.015.511.39.912.615.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.00.00.00.00.00.0

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value14462094176913201340195029282350251132862869198619992904234218191920246118381605139217341565136513462177215115741698286819731396
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax84.382.40.082.085.691.190.7112.3122.1129.494.5143.4138.0136.688.8135.0143.5143.888.385.088.487.487.483.787.989.590.787.190.190.790.385.1

us-gaap:CostsAndExpenses dei:LegalEntity

cnp:CercCorp


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value51095973741244181116611103128421722227131913062269169412201328
Percentage of CostsAndExpenses35.345.841.731.232.941.656.746.951.166.177.666.465.378.172.367.169.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax29.737.70.025.628.237.951.452.762.585.573.495.290.1106.764.290.699.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp91.40.00.098.893.482.40.0231.2215.1158.30.0274.8222.5166.30.0247.5229.4

cnp:HoustonElectric


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value616577619596568552581590596605630670673636638589581
Percentage of CostsAndExpenses42.627.635.045.242.428.319.825.123.718.422.033.733.721.927.232.430.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax35.922.70.037.036.325.818.028.229.023.820.848.446.429.924.243.743.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric77.90.00.00.078.70.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations

us-gaap:IncomeLossFromContinuingOperations

us-gaap:IncomeLossFromContinuingOperations


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value251363200127135-1053.0137251151143
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.614.30.07.98.6-49.24.212.07.35.6

us-gaap:IncomeLossFromContinuingOperations dei:LegalEntity

cnp:CercCorp


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value581515.0-6.01713153-7.02813835-35.0-8.078469-4.0
Percentage of IncomeLossFromContinuingOperations23.141.62.5-4.712.6-12.438.7-2.818.596.50.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.45.90.0-0.41.16.11.6-0.31.45.41.2-2.5-0.63.717.8-0.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp10.40.00.0-1.43.613.30.0-1.54.710.10.0-7.3-1.45.70.0-0.8

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value248437254117164-1400.0182332224191181209-88.02122862672112991622768.0240-818.0-635.0114209209213169294175229144233210128200219159590190235164199
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.517.20.07.310.5-65.45.615.910.97.56.015.1-6.110.010.819.815.817.57.814.60.512.1-45.7-39.07.48.68.811.89.09.38.014.07.69.89.87.513.110.57.431.410.39.17.810.4

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity

cnp:CercCorp


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value4019380-15.01316642-8.02816443-37.04698135-5.083
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest16.144.231.5-12.87.9-11.923.1-2.412.585.923.8-17.7-52.346.247.2-1.939.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.37.60.0-0.90.87.81.3-0.41.46.51.4-2.73.24.65.1-0.46.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp7.20.00.0-3.62.816.90.0-1.74.712.00.0-7.77.87.20.0-1.014.3

cnp:HoustonElectric


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value1216163183103385422612333511791286778201117
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest48.814.024.8156.462.8-2.729.768.154.917.328.285.6-145.531.627.375.355.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.12.40.011.46.61.81.710.86.01.31.712.98.83.23.014.98.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric15.30.00.00.014.30.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupHeldForSaleOrDisposedOfBySaleNotDiscontinuedOperations, cnp:ArkansasAndOklahomaNaturalGasBusinesses


Income
Period End2021-06-302020-06-30
Value10.08.0
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest4.04.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.60.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:DisposalGroupHeldForSaleOrDisposedOfBySaleNotDiscontinuedOperations cnp:ArkansasAndOklahomaNaturalGasBusinesses0.00.0

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value251363127135-1053.0251151143
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.614.37.98.6-49.212.07.35.6

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity

cnp:CercCorp


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-6.017131-10.02.0110
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-4.712.6-12.4-4.01.376.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.41.16.1-0.50.14.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-1.43.613.3-2.10.38.0

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity, us-gaap:StatementBusinessSegments

cnp:CercCorp, cnp:NaturalGasDistribution


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value1.0201345.010.0119
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest0.814.8-12.72.06.683.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.11.36.30.20.54.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp cnp:NaturalGasDistribution0.00.00.00.00.00.0

cnp:CercCorp, us-gaap:CorporateAndOther


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-7.0-3.0-3.0-15.0-8.0-9.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-5.5-2.20.3-6.0-5.3-6.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.4-0.2-0.1-0.7-0.4-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp us-gaap:CorporateAndOther0.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

cnp:CorporateAndReconcilingItems, us-gaap:CorporateAndOther


Income
Period End2021-06-302020-06-30
Value-2.0-25.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-0.8-18.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.1-1.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CorporateAndReconcilingItems us-gaap:CorporateAndOther0.00.0

us-gaap:CorporateNonSegment, us-gaap:CorporateAndOther


Income
Period End2021-03-312020-03-31
Value-12.07.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-3.3-0.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.50.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateNonSegment us-gaap:CorporateAndOther0.00.0

us-gaap:OperatingSegments, cnp:ElectricSegment


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value12575106-134.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest49.820.778.512.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.33.06.8-6.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments cnp:ElectricSegment0.00.00.00.0

us-gaap:OperatingSegments, cnp:MidstreamInvestmentsSegment


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value547124-1127.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest21.519.617.8107.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.12.81.5-52.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments cnp:MidstreamInvestmentsSegment0.00.00.00.0

us-gaap:OperatingSegments, cnp:NaturalGasSegment


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value7422930201
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest29.563.122.2-19.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.39.01.99.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments cnp:NaturalGasSegment0.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementBusinessSegments

cnp:ElectricTransmissionDistribution


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value157873718510030
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest123.664.4-3.573.766.221.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.85.61.78.84.91.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution0.00.00.00.00.00.0

cnp:IndianaElectricIntegrated


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value3119-171.03416-9.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest24.414.116.213.510.6-6.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.91.2-8.01.60.8-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated0.00.00.00.00.00.0

cnp:MidstreamInvestments


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-62.024-1127.0505024
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-48.817.8107.019.933.116.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-3.91.5-52.62.42.40.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:MidstreamInvestments0.00.00.00.00.00.0

cnp:NaturalGasDistribution


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value5.0332046.023120
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest3.924.4-19.42.415.283.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.32.19.50.31.14.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution0.00.00.00.00.00.0

us-gaap:CorporateAndOther


Income
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-4.0-28.04.0-24.0-38.0-22.0
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest-3.1-20.7-0.4-9.6-25.2-15.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-1.80.2-1.1-1.8-0.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther0.0-34.15.10.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-3.07454-10.029-347.0256229226151-13.047-1010.09876107619710.086-309.0-244.03778337062109627824486761187472422047187407645102
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.22.90.0-0.61.9-16.20.83.01.40.92.03.7-0.92.2-38.37.35.76.22.95.10.64.3-17.3-15.02.43.21.43.93.33.42.84.812.93.63.66.94.93.52.010.83.93.41.94.02.63.4

us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity

cnp:CercCorp


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-18.04275-9.0-4.035-11.0-1.00.0268.0-2.010.020-334.0-1.029
Percentage of IncomeTaxExpenseBenefit600.056.8138.990.0-13.8-10.1-44.0-1.60.0118.213.1-3.9-76.942.633.1-1.038.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.01.70.0-0.6-0.31.6-0.3-0.00.01.00.3-0.10.70.9-12.7-0.12.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-3.20.00.0-2.2-0.83.60.0-0.20.01.90.0-0.41.71.50.0-0.25.0

cnp:HoustonElectric


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value188.06.026165.010.041236.011362715-132.07142
Percentage of IncomeTaxExpenseBenefit-600.010.811.1-260.055.2-1.440.066.179.327.318.070.6-207.731.913.172.455.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.00.30.01.61.00.20.32.01.10.20.42.61.90.7-5.05.33.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric2.30.00.00.02.20.00.00.00.00.00.00.00.00.00.00.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet

us-gaap:IncomeTaxesPaidNet


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value17-4.0261134.00.0-19.032146-4.00.01.092-4.01.03.013-2.01.02132-158.0-57.050128-166.03517141-1.0-42.010.070-3.00.07.047-8.0-1.02.0-46.0-160.0-3.066152-8.0
Percentage of IncomeTaxesPaidNet100.0100.0100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.0-0.20.07.00.30.0-0.61.57.1-0.20.00.16.3-0.20.00.21.0-0.10.01.12.0-8.0-3.23.18.4-6.81.50.97.5-0.0-1.90.63.7-0.10.00.43.1-0.4-0.00.1-2.5-6.2-0.13.58.7-0.3

us-gaap:IncomeTaxesPaidNet dei:LegalEntity

cnp:CercCorp


Income
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.04.00.00.04.00.03.00.00.00.03.00.00.01.0
Percentage of IncomeTaxesPaidNet0.03.50.00.0-21.10.02.1-0.00.00.03.3-0.00.033.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.20.00.00.10.00.10.00.00.00.20.00.00.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp0.01.00.00.00.00.00.50.00.00.00.50.00.00.2

cnp:HoustonElectric


Income
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value32330.00.0-6.020730.0322.0104160.00.0
Percentage of IncomeTaxesPaidNet123.129.20.00.031.662.550.0-0.00.0200.0113.0-400.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.02.00.00.0-0.21.03.60.01.10.17.20.80.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest And Debt Expense

us-gaap:InterestAndDebtExpense

us-gaap:InterestAndDebtExpense


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1191131131211281391391341341211029091787880777882838687868889899288898482868598104104104110115114111116117121121122
Percentage of InterestAndDebtExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.94.40.07.58.26.54.36.46.54.83.46.56.33.73.05.95.84.63.94.45.54.44.85.45.83.73.94.94.72.73.85.24.54.14.96.16.85.35.46.16.04.55.66.36.94.0

us-gaap:InterestAndDebtExpense dei:LegalEntity

cnp:CercCorp


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value2524242829302928302930303329313231
Percentage of InterestAndDebtExpense21.021.221.223.122.721.620.920.922.424.029.433.336.337.239.740.040.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.50.90.01.71.91.40.91.31.51.11.02.22.31.41.22.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp4.50.00.06.76.13.00.05.95.02.10.06.25.62.10.06.55.4

cnp:HoustonElectric


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value4745444343414141424037323633313232
Percentage of InterestAndDebtExpense39.539.838.935.533.629.529.530.631.333.136.335.639.642.339.740.041.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.71.80.02.72.71.91.32.02.01.61.22.32.51.61.22.42.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric5.90.00.00.06.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Paid Net

us-gaap:InterestPaidNet

us-gaap:InterestPaidNet


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value10215914712848148721337715462134511167212470112821248711310311494115961358112281147100147110187811789519490186104213101191
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.96.30.08.03.16.92.26.43.76.12.09.73.55.52.79.25.26.53.96.65.55.75.87.06.14.74.07.54.33.93.79.05.36.25.111.05.38.54.410.34.97.25.011.25.86.3

us-gaap:InterestPaidNet dei:LegalEntity

cnp:CercCorp


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value26212633203521332035203511393030
Percentage of InterestPaidNet25.513.217.725.841.723.629.224.826.022.732.326.121.633.641.724.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.50.80.02.01.31.60.71.61.01.40.72.50.81.81.12.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp4.70.00.07.94.23.60.06.93.42.60.07.31.92.90.06.1

cnp:HoustonElectric


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value22702583256826902786278329612982
Percentage of InterestPaidNet21.644.017.064.852.145.936.167.735.155.843.561.956.952.640.366.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.32.80.05.21.63.20.84.31.33.40.96.02.02.91.16.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric2.80.00.00.03.50.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value251363200121105-1199.0157270195169120158-75.01651296169135192101179-2.0154-509.0-391.077131176143107185113151-100.014713410.0126147117973119148124123811141051148667
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.614.30.07.56.7-56.04.912.99.56.74.011.4-5.27.849.112.510.111.24.99.5-0.17.8-28.4-24.05.05.47.47.95.75.85.29.2-5.36.26.30.68.37.15.551.76.55.75.96.44.63.84.67.25.22.4

us-gaap:NetIncomeLoss dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value581515.0-4.0136753-7.028138339.0361305063854
Percentage of NetIncomeLoss23.141.62.5-3.312.4-5.633.8-2.614.481.727.55.7-48.078.839.022.540.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.45.90.0-0.20.83.11.6-0.31.45.41.10.62.56.119.22.84.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp10.40.00.0-1.02.86.80.0-1.54.710.10.01.96.19.50.07.79.3

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value10353571578733441851002740143101522101307518
Percentage of NetIncomeLoss41.014.628.5129.882.9-2.828.068.551.316.033.390.5-134.731.516.276.955.69.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.02.10.09.85.61.51.48.84.91.11.310.37.02.48.09.75.61.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric13.00.00.00.012.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

cnp:CercCorp, us-gaap:RetainedEarnings


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
Value581515.0-4.0136753-7.028138339.036130
Percentage of NetIncomeLoss23.141.62.5-3.312.4-5.633.8-2.614.481.727.55.7-48.078.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.45.90.0-0.20.83.11.6-0.31.45.41.10.62.56.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:RetainedEarnings


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
Value1035357157873344185100274014310152
Percentage of NetIncomeLoss41.014.628.5129.882.9-2.828.068.551.316.033.390.5-134.731.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.02.10.09.85.61.51.48.84.91.11.310.37.02.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value251363200121105-1199.0157270195169120158-75.0165
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.614.30.07.56.7-56.04.912.99.56.74.011.4-5.27.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2213341516959-1228.012824116514090153-75.01651296169135192
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax12.913.10.04.33.8-57.44.011.58.05.53.011.0-5.27.849.112.510.111.2

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic dei:LegalEntity

cnp:EnableMidstreamPartners


Net
Period End2021-03-312020-03-31
Value155103
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic46.4-8.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.14.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Net
Period End2021-06-302020-12-312020-09-302020-06-302019-12-312019-09-302019-06-30
Value7987-173.0359.0123115
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic35.757.6-250.759.37.051.069.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.60.0-10.72.20.35.95.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.00.00.00.00.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:StatementOperatingActivitiesSegment

us-gaap:SegmentContinuingOperations


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1517589-1082.0108222121114
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0108.7150.888.184.492.173.381.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.04.75.7-50.53.310.65.94.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SegmentContinuingOperations0.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Diluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value22135159-1228.012824116514090153-75.0165
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax12.913.83.8-57.44.011.58.05.53.011.0-5.27.8

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense

us-gaap:NonoperatingIncomeExpense


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-48.0-16.0-31.0-185.0-71.0-1617.0-120.0-60.0-63.0-54.014-17.0-275.0-39.0-10.0-12.0-12.025-81.0-8.0-174.0-10.0-1044.0-900.0-72.0-47.0-12.0-20.0-17.0-1.0-36.0-15.0-79.0-99.0-100.040-102.0-119.0-115.0233-113.0-129.0-138.0-128.0-137.0-141.0
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.8-0.60.0-11.5-4.5-75.5-3.7-2.9-3.1-2.10.5-1.2-19.0-1.8-0.4-0.9-0.91.5-3.9-0.4-11.1-0.5-58.3-55.2-4.7-1.9-0.5-1.1-0.9-0.0-1.6-0.9-4.2-4.1-4.72.3-6.7-5.7-5.412.4-6.2-5.0-6.6-6.7-7.8-4.7

us-gaap:NonoperatingIncomeExpense dei:LegalEntity

cnp:CercCorp


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-24.0-25.0-26.0-29.0-29.0-34.0-31.0-31.0-30.0-32.0-33.0-30.024-33.0-43.0-36.024
Percentage of NonoperatingIncomeExpense50.0156.283.915.740.82.125.851.747.659.3-235.7176.5-8.784.6430.0300.0-200.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.4-1.00.0-1.8-1.9-1.6-1.0-1.5-1.5-1.3-1.1-2.21.7-1.6-1.6-2.71.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-4.30.00.0-7.0-6.1-3.50.0-6.5-5.0-2.30.0-6.24.1-2.40.0-7.34.1

cnp:HoustonElectric


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-49.0-46.0-47.0-49.0-49.0-44.0-45.0-43.0-46.0-48.0-47.0-48.0-53.0-52.0-49.0-53.0-54.0
Percentage of NonoperatingIncomeExpense102.1287.5151.626.569.02.737.571.773.088.9-335.7282.419.3133.3490.0441.7450.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.9-1.80.0-3.0-3.1-2.1-1.4-2.1-2.2-1.9-1.5-3.5-3.7-2.4-1.9-3.9-4.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric-6.20.00.00.0-6.80.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value29645328530223521730239228724516722618725129627922327424328418225022626518625622123318629521124422333231088302338274357303364302327263357299287253285
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax17.317.80.018.815.010.19.318.714.09.65.516.312.911.811.220.716.716.011.715.011.612.612.616.312.110.59.312.99.99.39.714.911.813.914.55.219.816.212.819.016.514.114.417.115.011.813.018.215.410.3

us-gaap:OperatingIncomeLoss dei:LegalEntity

cnp:CercCorp


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value64218106144220073235819676-7.0221311783159
Percentage of OperatingIncomeLoss21.648.137.24.617.992.224.25.920.280.045.5-3.111.852.260.111.126.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.78.60.00.92.79.32.31.12.87.72.5-0.51.56.26.72.34.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp11.50.00.03.48.920.30.04.89.714.30.0-1.53.79.60.06.310.2

cnp:EnableMidstreamPartners


Operating
Period End2021-03-312020-03-31
Value206146
Percentage of OperatingIncomeLoss45.567.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.16.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.0

cnp:HoustonElectric


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1701071102321528299269169819822718111912725417185
Percentage of OperatingIncomeLoss57.423.638.676.864.737.832.868.658.933.158.7100.496.847.442.991.076.731.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.94.20.014.49.73.83.112.98.23.23.216.412.55.64.818.912.85.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric21.50.00.00.021.10.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingIncomeLoss us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Operating
Period End2021-06-302020-09-302020-06-302019-09-302019-06-30
Value12410080175167
Percentage of OperatingIncomeLoss41.933.134.044.658.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.26.25.18.48.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.00.00.00.0

Other Comprehensive Income Loss Net Of Tax

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

us-gaap:OtherComprehensiveIncomeLossNetOfTax

cnp:HoustonElectric, us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.0150.00.00.00.0-1.0-21.03.00.04.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.00.0100.00.00.00.00.0100.0100.0100.00.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.01.00.00.00.00.0-0.0-0.70.20.00.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.03.0-8.02.016-2.09.0-2.02.01.0-35.04.01.05.0
Percentage of OtherComprehensiveIncomeLossNetOfTax0.00.00.00.0106.70.00.00.00.0-100.0166.7133.30.0125.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.10.00.11.0-0.10.3-0.10.10.0-1.20.30.10.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value11-8.01610.0211310.09.01120349.04.03.010.0171617-6.020147.010.01213118.010.09.09.07.0110.06.010.01210.06.04.010.04.05.05.03.03.01.0
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.6-0.30.00.61.30.60.30.40.50.81.10.60.30.10.41.31.21.0-0.31.10.90.40.60.70.80.50.30.60.50.30.30.70.00.30.50.70.70.30.20.50.20.20.20.20.20.0

us-gaap:OtherNonoperatingIncomeExpense dei:LegalEntity

cnp:CercCorp


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value1.0-1.0-2.0-1.00.0-4.0-2.0-3.00.0-3.0-3.00.0-1.0-4.0-12.0-4.0-4.0
Percentage of OtherNonoperatingIncomeExpense9.112.5-12.5-10.00.0-30.8-20.0-33.30.0-15.0-8.80.0-25.0-133.3-120.0-23.5-25.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.1-0.00.0-0.10.0-0.2-0.1-0.10.0-0.1-0.10.0-0.1-0.2-0.5-0.3-0.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp0.20.00.0-0.20.0-0.40.0-0.60.0-0.20.00.0-0.2-0.30.0-0.8-0.7

cnp:HoustonElectric


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value3.05.03.00.01.03.04.07.06.04.03.00.0-3.0-3.01.0-3.0-2.0
Percentage of OtherNonoperatingIncomeExpense27.3-62.518.80.04.823.140.077.854.520.08.80.0-75.0-100.010.0-17.6-12.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.20.00.00.10.10.10.30.30.20.10.0-0.2-0.10.0-0.2-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric0.40.00.00.00.10.00.00.00.00.00.00.00.00.00.00.00.0

Preferred Stock Dividends Income Statement Impact

us-gaap:PreferredStockDividendsIncomeStatementImpact

us-gaap:PreferredStockDividendsIncomeStatementImpact


Preferred
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
Value30294236372929293029305.00.00.0
Percentage of PreferredStockDividendsIncomeStatementImpact100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.71.10.02.22.41.40.91.41.51.11.00.40.00.0

us-gaap:PreferredStockDividendsIncomeStatementImpact us-gaap:StatementClassOfStock

us-gaap:SeriesAPreferredStock


Preferred
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
Value13121212131212121312135.00.00.0
Percentage of PreferredStockDividendsIncomeStatementImpact43.341.428.633.335.141.441.441.443.341.443.3100.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.80.50.00.70.80.60.40.60.60.50.40.40.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SeriesAPreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:SeriesBPreferredStock


Preferred
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
Value17171717171717171717170.00.00.0
Percentage of PreferredStockDividendsIncomeStatementImpact56.758.640.547.245.958.658.658.656.758.656.70.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.00.70.01.11.10.80.50.80.80.70.60.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SeriesBPreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:SeriesCPreferredStock


Preferred
Period End2020-12-312020-09-302020-06-30
Value137.07.0
Percentage of PreferredStockDividendsIncomeStatementImpact31.019.418.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.40.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:SeriesCPreferredStock0.00.00.0

Regulated Operating Revenue

us-gaap:RegulatedOperatingRevenue

us-gaap:RegulatedOperatingRevenue


Regulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value1652248419621538147620731907153915552161162912991341189416021233122215461437127811771548
Percentage of RegulatedOperatingRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax96.397.80.095.594.396.859.073.575.685.153.793.892.589.160.791.591.390.369.167.774.878.0

us-gaap:RegulatedOperatingRevenue dei:LegalEntity

cnp:CercCorp


Regulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value549116883341546799683438950311858994024871143839390470
Percentage of RegulatedOperatingRevenue33.247.042.527.031.648.043.725.332.354.855.230.936.360.352.431.638.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax32.046.00.025.829.846.525.818.624.546.729.629.033.653.831.829.035.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp98.40.00.099.598.9101.20.081.684.386.40.083.883.083.80.079.181.2

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value17152541203316101566214132302093205625393036138514492126263813471338171220811889157419841791163015322433237218071884316321841640189423882138170515252084214518811837258720981908175630232299157616402766
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity

cnp:CercCorp


Revenue
Period End2021-06-302020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value558417472984984477597137210744805871364979493579
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax32.525.930.146.030.522.829.054.035.434.740.564.237.136.643.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax32.525.930.146.030.522.829.054.035.434.740.564.237.136.643.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric


Revenue
Period End2021-06-302020-06-30
Value791722
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.146.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.146.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity, us-gaap:StatementBusinessSegments

cnp:CercCorp, cnp:NaturalGasSegment


Revenue
Period End2021-03-312020-03-31
Value1172984
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.146.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.146.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp cnp:NaturalGasSegment100.0100.0

cnp:HoustonElectric, cnp:ElectricTransmissionDistribution


Revenue
Period End2021-03-312020-03-31
Value687638
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax27.029.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax27.029.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric cnp:ElectricTransmissionDistribution100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity, us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

cnp:CercCorp, cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value41447098184439351011989183985091186854396463
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax25.730.045.826.118.824.847.230.228.735.155.832.429.434.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax25.730.045.826.118.824.847.230.228.735.155.832.429.434.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp cnp:NaturalGasDistribution us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:CercCorp, us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-06-30
Value3.02.03.01.03.00.01.01.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.10.10.00.10.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.10.10.00.10.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp us-gaap:CorporateAndOther us-gaap:ReportableSubsegments100.0100.0100.0100.0100.00.0100.0100.00.00.00.00.0

cnp:HoustonElectric, cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments


Revenue
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value708828722638665861768690710904860761747852758
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.851.446.129.820.641.137.427.223.465.359.435.828.363.356.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.851.446.129.820.641.137.427.223.465.359.435.828.363.356.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:StatementBusinessSegments

cnp:Electric


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value933833850767
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax54.432.854.335.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax54.432.854.335.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:Electric100.0100.0100.0100.0

cnp:NaturalGasSegment


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value71816556341296
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax41.965.140.560.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax41.965.140.560.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasSegment100.0100.0100.0100.0

us-gaap:CorporateAndOther


Revenue
Period End2021-06-302021-03-312020-06-302020-03-31
Value64538278
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.72.15.23.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.72.15.23.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value828722638665861768690710904860761747852758644
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax51.446.129.820.641.137.427.223.465.359.435.828.363.356.737.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax51.446.129.820.641.137.427.223.465.359.435.828.363.356.737.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:IndianaElectricIntegrated, us-gaap:ReportableSubsegments


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value157128129135165140830.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.88.26.04.27.96.83.30.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.88.26.04.27.96.83.30.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments


Revenue
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value5506321293109951865714069183985091186854396463925
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.240.460.434.024.732.055.430.228.735.155.832.429.434.654.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.240.460.434.024.732.055.430.228.735.155.832.429.434.654.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments


Revenue
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
Value73758481859178412.01.02.01.01.02.01.01.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.64.75.43.82.64.33.81.60.10.10.10.00.00.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.64.75.43.82.64.33.81.60.10.10.10.00.00.10.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value17422547205416221575216732302742279835313036221221863155263820982143273520811889157419841791163015322433237218071884316321841640189423882138170515252084214518811837258720981908175630232299157616402766
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax101.6100.2101.0100.7100.6101.2100.0131.0136.1139.1100.0159.7150.9148.4100.0155.8160.2159.8100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues dei:LegalEntity

cnp:CercCorp


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value5741177843426483101117341126134223682303131213282400187212511387
Percentage of Revenues33.046.241.026.330.746.753.741.148.067.175.959.360.876.171.059.664.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax33.546.341.526.530.847.253.753.865.393.375.994.791.6112.971.092.9103.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp102.90.00.0102.2102.3102.7176.2236.1224.8172.6214.4273.3226.2176.0191.2253.8239.6

cnp:EnableMidstreamPartners


Revenuesdei:
Period End2021-03-312020-03-31
Value970648
Percentage of Revenues38.129.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax38.230.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.0

cnp:HoustonElectric


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value786684729828720634680859765686728897854755765843752638
Percentage of Revenues45.126.935.551.045.729.321.131.327.319.424.040.639.123.929.040.235.123.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax45.826.935.951.446.029.621.141.037.227.024.064.858.935.529.062.656.237.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric99.40.00.00.099.70.00.00.00.00.00.00.00.00.00.00.00.00.0

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

cnp:HoustonElectric, cnp:AffiliatesOfNrgEnergyInc


Revenuesdei:
Period End2021-06-302021-03-312020-06-302020-03-312019-06-302019-03-31
Value192195174156165151
Percentage of Revenues11.07.711.07.25.94.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.27.711.17.38.05.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric cnp:AffiliatesOfNrgEnergyInc0.00.00.00.00.00.0

cnp:HoustonElectric, cnp:AffiliatesofVistraEnergyCorp.


Revenuesdei:
Period End2021-06-302021-03-312020-06-302020-03-312019-06-302019-03-31
Value878892815954
Percentage of Revenues5.03.55.83.72.11.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.13.55.93.82.92.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric cnp:AffiliatesofVistraEnergyCorp.0.00.00.00.00.00.0

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

cnp:CercCorp, cnp:NaturalGasDistribution


Revenuesdei:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value422480100883438950311858994024871143839390470
Percentage of Revenues26.030.546.525.814.218.033.629.618.222.336.231.818.621.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.230.747.125.818.624.546.729.629.033.653.831.829.035.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp cnp:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:CercCorp, cnp:NaturalGasSegment


Revenuesdei:
Period End2021-03-312020-03-31
Value11771011
Percentage of Revenues46.246.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.347.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp cnp:NaturalGasSegment100.4102.7

cnp:CercCorp, us-gaap:CorporateAndOther


Revenuesdei:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value4.03.03.01.03.00.01.01.00.00.00.00.00.0-1.0
Percentage of Revenues0.20.20.10.00.10.00.00.00.00.00.00.00.0-0.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.20.10.00.10.00.00.00.00.00.00.00.0-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, cnp:ElectricTransmissionDistribution


Revenuesdei:
Period End2021-03-312020-03-31
Value684634
Percentage of Revenues26.929.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.929.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric cnp:ElectricTransmissionDistribution99.699.4

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

cnp:CercCorp, cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments


Revenuesdei:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value422480100883438950311858994024871143839390470
Percentage of Revenues26.030.546.525.814.218.033.629.618.222.336.231.818.621.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax26.230.747.125.818.624.546.729.629.033.653.831.829.035.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp cnp:NaturalGasDistribution us-gaap:ReportableSubsegments101.9102.1102.898.899.098.698.997.9101.095.796.498.298.5101.5

cnp:CercCorp, us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments


Revenuesdei:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-06-30
Value4.03.03.01.03.00.01.01.00.00.00.0-1.0
Percentage of Revenues0.20.20.10.00.10.00.00.00.00.00.0-0.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.20.10.00.10.00.00.00.00.00.0-0.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp us-gaap:CorporateAndOther us-gaap:ReportableSubsegments133.3150.0100.0100.0100.00.0100.0100.00.00.00.00.0

cnp:HoustonElectric, cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments


Revenuesdei:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value729828720634680859765686728897854755765843752
Percentage of Revenues35.551.045.729.321.131.327.319.424.040.639.123.929.040.235.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax35.951.446.029.621.141.037.227.024.064.858.935.529.062.656.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments103.0100.099.799.4102.399.899.699.4102.599.299.399.2102.498.999.2

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

cnp:CorporateAndReconcilingItems, us-gaap:CorporateAndOther


Revenuesus-gaap:
Period End2021-06-302020-06-30
Value6583
Percentage of Revenues3.75.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.85.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CorporateAndReconcilingItems us-gaap:CorporateAndOther0.00.0

us-gaap:CorporateNonSegment, us-gaap:CorporateAndOther


Revenuesus-gaap:
Period End2021-03-312020-03-31
Value5479
Percentage of Revenues2.13.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2.13.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateNonSegment us-gaap:CorporateAndOther0.00.0

us-gaap:OperatingSegments, cnp:ElectricSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value937830848767
Percentage of Revenues53.832.653.835.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax54.632.754.235.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments cnp:ElectricSegment0.00.00.00.0

us-gaap:OperatingSegments, cnp:NaturalGasSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value74016636441321
Percentage of Revenues42.565.340.961.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax43.165.441.161.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments cnp:NaturalGasSegment0.00.00.00.0

us-gaap:Revenues us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments

cnp:AffiliatesOfNrgEnergyInc, cnp:ElectricSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value192195174156
Percentage of Revenues11.07.711.07.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.27.711.17.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesOfNrgEnergyInc cnp:ElectricSegment0.00.00.00.0

cnp:AffiliatesOfNrgEnergyInc, cnp:ElectricTransmissionDistribution


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value243174156180231165151162213169161173221167152171223159145163222172184183222164166164202148144160196
Percentage of Revenues15.011.07.25.68.45.94.35.39.67.75.16.610.57.85.68.211.810.17.39.113.611.27.67.712.38.75.27.512.37.86.07.511.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax15.111.17.35.611.08.05.95.315.411.77.66.616.412.58.98.211.810.17.39.113.611.27.67.712.38.75.27.512.37.86.07.511.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesOfNrgEnergyInc cnp:ElectricTransmissionDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:AffiliatesofVistraEnergyCorp., cnp:ElectricSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value87889281
Percentage of Revenues5.03.55.83.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.13.55.93.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesofVistraEnergyCorp. cnp:ElectricSegment0.00.00.00.0

cnp:AffiliatesofVistraEnergyCorp., cnp:ElectricTransmissionDistribution


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value1289281678359545979595457725347547150
Percentage of Revenues7.95.83.72.13.02.11.51.93.62.71.72.23.42.51.72.63.83.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.05.93.82.14.02.92.11.95.74.12.52.25.34.02.72.63.83.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:AffiliatesofVistraEnergyCorp. cnp:ElectricTransmissionDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Revenuesus-gaap:
Period End2021-06-302020-12-312020-09-302020-06-302019-12-312019-09-302019-06-30
Value787704596515731699735
Percentage of Revenues45.234.336.732.722.625.526.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax45.934.637.032.922.633.435.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:EnableMidstreamPartners0.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:StatementBusinessSegments

cnp:Electric


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value937830848767
Percentage of Revenues53.832.653.835.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax54.632.754.235.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:Electric100.499.699.8100.0

cnp:ElectricTransmissionDistribution


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-30
Value828720638683859765689730897854751763843752639729908763660701827705612679839698629637745656532585748535707
Percentage of Revenues51.045.729.421.131.327.319.524.040.639.123.828.940.235.123.435.048.148.533.339.150.746.025.228.646.437.019.929.245.434.622.327.443.924.937.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax51.446.029.821.141.037.227.124.064.858.935.328.962.656.237.335.048.148.533.339.150.746.025.228.646.437.019.929.245.434.622.327.443.924.937.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:IndianaElectricIntegrated


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value157128129135165140830.00.00.0
Percentage of Revenues9.78.16.04.26.05.02.40.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.88.26.04.27.96.83.30.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated0.00.00.00.00.00.00.00.00.00.0

cnp:NaturalGasDistribution


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value56064113181089515650138989940248711438393904709077083704148886453534201185892375526147889537552410437603513608497893794481207809395
Percentage of Revenues34.540.760.833.718.823.239.329.618.222.336.231.818.621.933.234.019.626.344.836.021.727.448.737.620.827.946.741.022.927.743.735.520.623.640.736.820.124.446.738.620.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.840.961.633.724.631.654.729.629.033.653.831.829.035.153.034.019.626.344.836.021.727.448.737.620.827.946.741.022.927.743.735.520.623.640.736.820.124.446.738.620.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:NaturalGasSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value74016636441321
Percentage of Revenues42.565.340.961.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax43.165.441.161.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasSegment103.1100.5101.6101.9

us-gaap:CorporateAndOther


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-30
Value6554778682859380424.03.04.04.03.04.03.04.04.03.04.04.03.04.03.04.04.04.03.04.04.04.03.03.02.03.02.03.0
Percentage of Revenues3.72.14.75.53.82.63.42.91.20.10.10.20.10.10.20.10.10.20.20.30.20.20.20.20.20.20.20.20.10.20.20.20.10.10.20.10.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.82.14.85.53.82.64.43.91.70.10.20.30.20.10.30.20.20.20.20.30.20.20.20.20.20.20.20.20.10.20.20.20.10.10.20.10.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther101.6101.90.0104.9105.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems

cnp:ElectricTransmissionDistribution, us-gaap:ReportableSubsegments


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value828720638683859765689730897854751763843752639
Percentage of Revenues51.045.729.421.131.327.319.524.040.639.123.828.940.235.123.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax51.446.029.821.141.037.227.124.064.858.935.328.962.656.237.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:ElectricTransmissionDistribution us-gaap:ReportableSubsegments100.099.7100.0102.799.899.699.9102.899.299.398.7102.198.999.299.2

cnp:IndianaElectricIntegrated, us-gaap:ReportableSubsegments


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
Value157128129135165140830.00.00.00.0
Percentage of Revenues9.78.16.04.26.05.02.40.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.88.26.04.27.96.83.30.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:IndianaElectricIntegrated us-gaap:ReportableSubsegments100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

cnp:NaturalGasDistribution, us-gaap:ReportableSubsegments


Revenuesus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value5606411318108951565013898994024871143839390470907
Percentage of Revenues34.540.760.833.718.823.239.329.618.222.336.231.818.621.933.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax34.840.961.633.724.631.654.729.629.033.653.831.829.035.153.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:NaturalGasDistribution us-gaap:ReportableSubsegments101.8101.4101.999.199.498.998.897.9101.095.796.498.298.5101.598.1

us-gaap:CorporateAndOther, us-gaap:ReportableSubsegments


Revenuesus-gaap:
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
Value72778682859380424.03.04.04.03.04.03.04.0
Percentage of Revenues3.54.75.53.82.63.42.91.20.10.10.20.10.10.20.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.54.85.53.82.64.43.91.70.10.20.30.20.10.30.20.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CorporateAndOther us-gaap:ReportableSubsegments98.6102.7102.4101.2100.0102.2102.6102.4200.0300.0200.0400.0300.0200.0300.0400.0

Unregulated Operating Revenue

us-gaap:UnregulatedOperatingRevenue

us-gaap:UnregulatedOperatingRevenue


Unregulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value90639284999413231203124313701407913845126110368659211189644611397436
Percentage of UnregulatedOperatingRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax5.22.54.55.26.34.441.057.560.554.046.365.958.359.339.364.268.869.530.932.325.222.0

us-gaap:UnregulatedOperatingRevenue dei:LegalEntity

cnp:CercCorp


Unregulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value259.010.01116159007378391183140491084112571033861917
Percentage of UnregulatedOperatingRevenue27.814.310.913.116.216.068.061.367.586.499.899.799.599.799.799.599.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.50.40.50.71.00.727.935.240.846.646.265.758.059.139.263.968.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp4.50.00.02.63.41.591.5154.5140.586.2130.7189.6143.392.2105.5174.6158.4

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value364663590633471327053214833395354393464234189339022700922228221082241022736221352204521931218292128621012210042133421778226022267023200220482192022264218702157521658223702287122477224752235121703209511967719594201111977319676
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

cnp:CercCorp


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-31
Value103791035683087779759581508439792978158065821473059642101129218
Percentage of Assets28.528.824.823.823.624.423.822.922.923.830.432.943.644.542.2
Percentage of Assets28.528.824.823.823.624.423.822.922.923.830.432.943.644.542.2
Percentage of Assets cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value1201712185113161129611097108701126211463114781142010507104361043010292
Percentage of Assets33.033.933.834.534.532.531.833.133.633.738.946.947.245.3
Percentage of Assets33.033.933.834.534.532.531.833.133.633.738.946.947.245.3
Percentage of Assets cnp:HoustonElectric100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

cnp:CercCorp, us-gaap:OperatingSegments, cnp:NaturalGasDistribution


Assetsdei:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-31
Value780976097562749770186843690469566557650166086099
Percentage of Assets23.923.722.621.220.320.020.425.829.529.429.127.9
Percentage of Assets23.923.722.621.220.320.020.425.829.529.429.127.9
Percentage of Assets cnp:CercCorp us-gaap:OperatingSegments cnp:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:CercCorp, us-gaap:OperatingSegments, us-gaap:CorporateAndOther


Assetsdei:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-31
Value-30.0-14.0-87.01491211088066110897075
Percentage of Assets-0.1-0.0-0.30.40.30.30.20.20.50.40.30.3
Percentage of Assets-0.1-0.0-0.30.40.30.30.20.20.50.40.30.3
Percentage of Assets cnp:CercCorp us-gaap:OperatingSegments us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:CorporateNonSegment, cnp:CorporateAndOtherNet


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-31
Value287122943089
Percentage of Assets7.96.49.2
Percentage of Assets7.96.49.2
Percentage of Assets us-gaap:CorporateNonSegment cnp:CorporateAndOtherNet100.0100.0100.0

us-gaap:OperatingSegments, cnp:Electric


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-31
Value144931443210509
Percentage of Assets43.340.738.9
Percentage of Assets43.340.738.9
Percentage of Assets us-gaap:OperatingSegments cnp:Electric100.0100.0100.0

us-gaap:OperatingSegments, cnp:ElectricSegment


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-31
Value152881541014493
Percentage of Assets41.942.943.3
Percentage of Assets41.942.943.3
Percentage of Assets us-gaap:OperatingSegments cnp:ElectricSegment100.0100.0100.0

us-gaap:OperatingSegments, cnp:ElectricTransmissionDistribution


Assetsus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-31
Value112961109710870112641146311478114201050910436104301035810292102891031910245102111009010065996010049996099449788100669819980996051036411174
Percentage of Assets34.534.532.531.833.133.633.738.946.947.246.245.346.546.846.746.847.447.947.447.145.744.043.243.444.544.743.948.048.9
Percentage of Assets34.534.532.531.833.133.633.738.946.947.246.245.346.546.846.746.847.447.947.447.145.744.043.243.444.544.743.948.048.9
Percentage of Assets us-gaap:OperatingSegments cnp:ElectricTransmissionDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, cnp:IndianaElectricIntegrated


Assetsus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value31423083301531683009298919530.0
Percentage of Assets9.69.69.08.98.78.75.80.0
Percentage of Assets9.69.69.08.98.78.75.80.0
Percentage of Assets us-gaap:OperatingSegments cnp:IndianaElectricIntegrated100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:OperatingSegments, cnp:MidstreamInvestments


Assetsus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-30
Value9138059179152473252929152839248224572451246724722481248725022505253525362580259436044471450145214525451745184525
Percentage of Assets2.72.52.92.77.07.38.58.49.211.111.111.010.911.211.311.411.511.912.112.312.216.519.819.919.520.520.620.721.0
Percentage of Assets2.72.52.92.77.07.38.58.49.211.111.111.010.911.211.311.411.511.912.112.312.216.519.819.919.520.520.620.721.0
Percentage of Assets us-gaap:OperatingSegments cnp:MidstreamInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, cnp:MidstreamInvestmentsSegment


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-31
Value1051994913
Percentage of Assets2.92.82.7
Percentage of Assets2.92.82.7
Percentage of Assets us-gaap:OperatingSegments cnp:MidstreamInvestmentsSegment100.0100.0100.0

us-gaap:OperatingSegments, cnp:NaturalGas


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-31
Value14976140027188
Percentage of Assets44.739.526.6
Percentage of Assets44.739.526.6
Percentage of Assets us-gaap:OperatingSegments cnp:NaturalGas100.0100.0100.0

us-gaap:OperatingSegments, cnp:NaturalGasDistribution


Assetsus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-31
Value142971405513979139031323512946104926956655765016438660860676022597560995732558556615657536053015335546450594989497647764775
Percentage of Assets43.743.741.939.238.237.930.925.829.529.428.729.127.427.327.227.926.926.627.026.524.623.523.523.622.922.822.822.120.9
Percentage of Assets43.743.741.939.238.237.930.925.829.529.428.729.127.427.327.227.926.926.627.026.524.623.523.523.622.922.822.822.120.9
Percentage of Assets us-gaap:OperatingSegments cnp:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, cnp:NaturalGasSegment


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-31
Value150641720814976
Percentage of Assets41.347.944.7
Percentage of Assets41.347.944.7
Percentage of Assets us-gaap:OperatingSegments cnp:NaturalGasSegment100.0100.0100.0

us-gaap:OperatingSegments, us-gaap:CorporateAndOther


Assetsus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-31
Value308931652996296947844884427835156156220623112500249726942703267926812920277129532902283129993153336827592902302627802600
Percentage of Assets9.29.79.38.913.514.112.510.422.89.910.511.211.012.212.312.212.313.713.214.113.613.013.313.914.512.513.213.812.911.4
Percentage of Assets9.29.79.38.913.514.112.510.422.89.910.511.211.012.212.312.212.313.713.214.113.613.013.313.914.512.513.213.812.911.4
Percentage of Assets us-gaap:OperatingSegments us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:StatementOperatingActivitiesSegment

us-gaap:SegmentContinuingOperations


Assetsus-gaap:
Period End2021-06-302020-12-312019-12-312018-12-31
Value34274334713356525984
Percentage of Assets94.0100.094.796.2
Percentage of Assets94.0100.094.796.2
Percentage of Assets us-gaap:SegmentContinuingOperations100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3646635906334713270532148333953543934642341893390227009222282210822410227362213522045219312182921286210122100421334217782260222670232002204821920222642187021575216582237022871224772247522351217032095119677195942011119773
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity

cnp:CercCorp


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value10379103568308777975958150843979297815806582147305964210112
Percentage of LiabilitiesAndStockholdersEquity28.528.824.823.823.624.423.822.922.923.830.432.943.644.5
Percentage of Assets28.528.824.823.823.624.423.822.922.923.830.432.943.644.5
Percentage of Assets cnp:CercCorp100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value1201712185113161129611097108701126211463114781142010507104361043010292
Percentage of LiabilitiesAndStockholdersEquity33.033.933.834.534.532.531.833.133.633.738.946.947.245.3
Percentage of Assets33.033.933.834.534.532.531.833.133.633.738.946.947.245.3
Percentage of Assets cnp:HoustonElectric100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value887087168348838883926970835983468257821680585508467048574688361835633537346034723397350634614058455045744548447344254414432942614191437143014257433242864222420733133266319826392022
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.324.324.925.626.120.923.624.124.224.229.824.821.121.720.616.316.216.115.916.316.216.716.218.620.120.219.620.320.219.819.819.719.419.518.818.919.319.219.520.116.816.715.913.310.3

us-gaap:StockholdersEquity dei:LegalEntity

cnp:CercCorp


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value2776271825672345235726712641248325062561244321373063315131082922
Percentage of StockholdersEquity31.331.230.728.028.138.331.629.830.431.230.338.865.664.966.384.5
Percentage of Assets7.67.67.77.27.38.07.57.27.37.69.09.613.914.113.713.4
Percentage of Assets cnp:CercCorp26.726.230.930.131.032.831.331.332.131.829.729.331.80.030.731.7

cnp:HoustonElectric


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3267316431113086298128993251348333583274268225492464239423692117
Percentage of StockholdersEquity36.836.337.336.835.541.638.941.740.739.833.346.352.849.350.561.2
Percentage of Assets9.08.89.39.49.38.79.210.19.89.79.911.511.110.710.49.7
Percentage of Assets cnp:HoustonElectric27.226.027.527.326.926.728.930.429.328.725.524.423.60.023.00.0

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

cnp:CercCorp, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value10.010.010.010.010.010.010.05.05.05.05.06.06.06.06.03.09.0
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.3
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets cnp:CercCorp us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:CercCorp, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value20462046204618291829211621162015201520152015166825282527252824892417
Percentage of StockholdersEquity23.123.524.521.821.830.425.324.124.424.525.030.354.152.053.971.969.8
Percentage of Assets5.65.76.15.65.76.36.05.85.95.97.57.511.411.311.111.411.3
Percentage of Assets cnp:CercCorp us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:CercCorp, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value720662511506518545515463486541423463529618574430828
Percentage of StockholdersEquity8.17.66.16.06.27.86.25.55.96.65.28.411.312.712.212.423.9
Percentage of Assets2.01.81.51.51.61.61.51.31.41.61.62.12.42.82.52.03.9
Percentage of Assets cnp:CercCorp us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value25482548254824862486248624862486248624861896169616971697169616961322
Percentage of StockholdersEquity28.729.230.529.629.635.729.729.830.130.323.530.836.334.936.249.038.2
Percentage of Assets7.07.17.67.67.77.47.07.27.37.37.07.67.77.67.57.86.2
Percentage of Assets cnp:HoustonElectric us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value7196165636004954287801012887803800846763693673420279
Percentage of StockholdersEquity8.17.16.77.25.96.19.312.110.79.89.915.416.314.314.412.18.1
Percentage of Assets2.01.71.71.81.51.32.22.92.62.43.03.83.53.13.01.91.3
Percentage of Assets cnp:HoustonElectric us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Stockholders
Period End2020-12-312020-09-302020-06-302019-12-31
Value6713669569377013
Percentage of StockholdersEquity80.479.882.783.9
Percentage of Assets20.120.521.619.8
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-85.0-87.0-90.0-82.0-84.0-100.0-98.0-107.0-105.0-107.0-108.0-58.0-62.0-63.0-68.0-71.0-66.0-86.0-90.0-135.0-133.0-117.0-124.0-131.0
Percentage of StockholdersEquity-1.0-1.0-1.1-1.0-1.0-1.4-1.2-1.3-1.3-1.3-1.3-1.1-1.3-1.3-1.5-2.1-1.9-1.9-2.1-3.1-3.2-3.7-4.7-6.5
Percentage of Assets-0.2-0.2-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.4-0.6-0.6-0.6-0.6-0.7
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 End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value7553691669146805680160866080607260656060607242214215420842094195418041694157413041204100367131583046
Percentage of StockholdersEquity85.279.382.881.181.087.372.772.873.573.875.476.690.386.689.8121.2120.891.796.096.097.6128.2139.1156.20.0
Percentage of Assets20.719.320.720.821.218.217.217.517.717.922.519.019.118.818.519.219.618.019.018.119.020.418.616.10.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value6.06.06.05.05.05.05.05.05.05.05.04.04.04.04.04.04.04.04.04.04.04.04.03.03.0
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.10.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value173923632363245624411740174017401740174017407900.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of StockholdersEquity19.627.128.329.329.125.020.820.821.121.221.614.30.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets4.86.67.17.57.65.24.95.05.15.16.43.60.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-343.0-482.0-845.0-796.0-771.0-761.0632636552518349551513708543-668.0-657.0461258302231-789.0-912.0-1008.0-1194.0
Percentage of StockholdersEquity-3.9-5.5-10.1-9.5-9.2-10.97.67.66.76.34.310.011.014.611.6-19.3-19.010.16.07.05.5-24.7-34.6-49.90.0
Percentage of Assets-0.9-1.3-2.5-2.4-2.4-2.31.81.81.61.51.32.52.33.22.4-3.1-3.12.01.21.31.1-3.9-4.6-5.10.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value51793219292027852501416438473416332634197025272627013049339529352865289629232529227223352689240025092691326825762529295526582319248023632874275229552968233719822042201425822904
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets14.29.08.78.57.812.510.99.99.710.126.012.312.213.614.913.313.013.213.411.910.811.112.611.011.111.914.111.711.513.312.210.711.510.612.612.213.113.310.89.510.410.312.814.7

us-gaap:AssetsCurrent dei:LegalEntity

cnp:CercCorp


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value26141000707568541126314151074115915471770106010401592
Percentage of AssetsCurrent50.531.124.220.421.630.336.831.434.845.225.238.938.546.9
Percentage of Assets7.22.82.11.71.73.84.03.13.44.66.64.84.77.0
Percentage of Assets cnp:CercCorp25.29.78.57.37.115.516.813.514.819.221.514.510.815.7

cnp:EnableMidstreamPartners


Assets
Period End2021-03-312020-12-31
Value449381
Percentage of AssetsCurrent13.913.0
Percentage of Assets1.31.1
Percentage of Assets cnp:EnableMidstreamPartners0.00.0

cnp:HoustonElectric


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value911139776991885173612901666173617869499941003830
Percentage of AssetsCurrent17.643.426.333.034.017.733.548.852.252.213.536.537.124.4
Percentage of Assets2.53.92.32.82.62.23.64.85.15.33.54.54.53.7
Percentage of Assets cnp:HoustonElectric7.611.56.88.17.76.811.514.515.115.69.09.59.68.1

us-gaap:AssetsCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Assets
Period End2021-06-302020-12-312020-09-302020-06-302019-12-31
Value475381373374389
Percentage of AssetsCurrent9.213.013.415.010.1
Percentage of Assets1.31.11.11.21.1
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.00.0

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value1361461471851682202412592712554231293328219260201248254341270271218264227245234298230206379208219497245646722112310962201031909519999583329740167129
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.40.40.60.50.70.70.70.80.815.71.31.51.01.10.91.11.21.61.31.31.01.21.01.11.01.31.00.91.71.01.02.31.12.83.25.04.91.00.51.00.51.00.00.00.03.70.80.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity

cnp:CercCorp


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302016-12-31
Value1.01.01.02.01.01.02.02.01.01.0141.01.0121.01.01.0
Percentage of CashAndCashEquivalentsAtCarryingValue0.70.70.71.10.60.50.80.80.40.40.30.30.34.60.50.40.3
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.10.00.00.10.00.00.0
Percentage of Assets cnp:CercCorp0.00.00.00.00.00.00.00.00.00.00.20.00.00.10.00.00.0

cnp:HoustonElectric


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value120143139172151196216228260243335279253238
Percentage of CashAndCashEquivalentsAtCarryingValue88.297.994.693.089.989.189.688.095.995.37.995.277.191.5
Percentage of Assets0.30.40.40.50.50.60.60.70.80.71.21.31.11.0
Percentage of Assets cnp:HoustonElectric1.01.21.21.51.41.81.92.02.32.13.22.72.42.3

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity, us-gaap:ConsolidatedEntities

cnp:HoustonElectric, cnp:BondCompanies


Cash
Period End2021-06-302021-03-312020-12-312019-12-312018-12-312017-12-31
Value106142139216335230
Percentage of CashAndCashEquivalentsAtCarryingValue77.997.394.689.67.988.5
Percentage of Assets0.30.40.40.61.21.0
Percentage of Assets cnp:HoustonElectric cnp:BondCompanies0.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:VariableInterestEntityPrimaryBeneficiary


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value106142139172149190216
Percentage of CashAndCashEquivalentsAtCarryingValue77.997.394.693.088.786.489.6
Percentage of Assets0.30.40.40.50.50.60.6
Percentage of Assets cnp:HoustonElectric us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.00.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue us-gaap:ConsolidatedEntities

us-gaap:VariableInterestEntityPrimaryBeneficiary


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value106142139172149190216
Percentage of CashAndCashEquivalentsAtCarryingValue77.997.394.693.088.786.489.6
Percentage of Assets0.30.40.40.50.50.60.6
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.00.00.0

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
Value1571671672081942472712973323554278331366257296233280290381300
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 Assets0.40.50.50.60.60.70.80.91.01.015.81.51.71.11.31.11.31.31.71.4

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents dei:LegalEntity

cnp:CercCorp


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value1.01.01.02.01.01.02.02.05.012251.01.027121.00.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents0.60.60.61.00.50.40.70.71.53.40.60.30.310.54.10.30.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.10.00.00.10.10.00.0
Percentage of Assets cnp:CercCorp0.00.00.00.00.00.00.00.00.10.10.30.00.00.00.10.00.0

cnp:HoustonElectric


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value137159154188170215235247293277370317291229274240277381299
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents87.395.292.290.487.687.086.783.288.378.08.695.879.589.192.6103.098.9100.099.7
Percentage of Assets0.40.40.50.60.50.60.70.70.90.81.41.41.31.01.21.11.31.71.4
Percentage of Assets cnp:HoustonElectric1.11.31.41.71.52.02.12.22.62.43.53.02.80.02.70.00.00.00.0

Marketable Securities Current

us-gaap:MarketableSecuritiesCurrent

us-gaap:MarketableSecuritiesCurrent


Marketable
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value92384887183675367882274668762354062758494496010571020997953814737894805826960913930840809737767689635614540522445432386337417399367300218357
Percentage of MarketableSecuritiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.52.42.62.62.32.02.32.22.01.82.02.82.64.24.24.84.64.54.43.83.54.33.83.84.24.04.03.83.73.33.53.22.92.72.42.32.01.91.81.62.12.01.81.51.10.0

us-gaap:MarketableSecuritiesCurrent us-gaap:FinancialInstrument

cnp:TWSecurities


Marketable
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value871822540960953805
Percentage of MarketableSecuritiesCurrent100.0100.0100.0100.0100.0100.0
Percentage of Assets2.62.32.04.24.43.8
Percentage of Assets cnp:TWSecurities0.00.00.00.00.00.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value65178067673173571112491091117314151190918958108110007837628407406826055775935686408978377128341142851617694860768698643713773722750852835790
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.82.22.02.22.32.13.53.13.44.24.44.14.34.84.43.53.53.83.43.22.92.72.82.62.84.03.63.23.85.13.92.93.23.83.43.12.93.23.63.43.84.34.24.0

us-gaap:AccountsReceivableNetCurrent dei:LegalEntity

cnp:CercCorp


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value199349233231265324693428506856894527566713
Percentage of AccountsReceivableNetCurrent30.644.734.531.636.145.655.539.243.160.575.157.459.171.3
Percentage of Assets0.51.00.70.70.81.02.01.21.52.53.32.42.63.1
Percentage of Assets cnp:CercCorp1.93.42.83.03.54.08.25.46.510.610.97.25.97.1

cnp:HoustonElectric


Accounts
Period End2021-06-302021-03-312020-12-31
Value313263268
Percentage of AccountsReceivableNetCurrent48.133.739.6
Percentage of Assets0.90.70.8
Percentage of Assets cnp:HoustonElectric2.62.22.4

us-gaap:AccountsReceivableNetCurrent dei:LegalEntity, us-gaap:ConsolidatedEntities

cnp:HoustonElectric, us-gaap:VariableInterestEntityPrimaryBeneficiary


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value38242330272226
Percentage of AccountsReceivableNetCurrent5.83.13.44.13.73.12.1
Percentage of Assets0.10.10.10.10.10.10.1
Percentage of Assets cnp:HoustonElectric us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.00.00.0

us-gaap:AccountsReceivableNetCurrent us-gaap:ConsolidatedEntities

us-gaap:VariableInterestEntityPrimaryBeneficiary


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value38242330272226
Percentage of AccountsReceivableNetCurrent5.83.13.44.13.73.12.1
Percentage of Assets0.10.10.10.10.10.10.1
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.00.00.0

Inventory Raw Materials And Supplies

us-gaap:InventoryRawMaterialsAndSupplies

us-gaap:InventoryRawMaterialsAndSupplies


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-312009-12-31
Value319310297300304278269273267256200198192176175190192178181191187176179174178161168156155146145137137181177182176168166168164138
Percentage of InventoryRawMaterialsAndSupplies100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.90.90.90.90.90.80.80.80.80.80.70.90.90.80.80.90.90.80.80.90.90.80.80.80.80.70.70.70.70.70.70.60.60.80.80.80.80.80.80.80.80.7

us-gaap:InventoryRawMaterialsAndSupplies dei:LegalEntity

cnp:CercCorp


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
Value6464586880747173716765696756
Percentage of InventoryRawMaterialsAndSupplies20.120.619.522.726.326.626.426.726.626.232.534.834.932.0
Percentage of Assets0.20.20.20.20.20.20.20.20.20.20.20.30.30.2
Percentage of Assets cnp:CercCorp0.60.60.70.91.10.90.80.90.90.80.80.90.70.6

cnp:HoustonElectric


Inventory
Period End2021-06-302021-03-312020-12-31
Value209202195
Percentage of InventoryRawMaterialsAndSupplies65.565.265.7
Percentage of Assets0.60.60.6
Percentage of Assets cnp:HoustonElectric1.71.71.7

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

us-gaap:PrepaidExpenseAndOtherAssetsCurrent


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value483646139113108120161156181241192157167189241175167184161154135127140111105132178177173158125112116137216245253220192190274
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.31.80.40.30.30.40.50.50.50.70.70.70.80.81.10.80.80.80.70.70.60.60.70.50.50.60.80.80.80.70.60.50.50.60.91.11.11.00.90.91.4

us-gaap:PrepaidExpenseAndOtherAssetsCurrent dei:LegalEntity

cnp:CercCorp


Prepaid
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
Value24138126110.08.0443639651158580166
Percentage of PrepaidExpenseAndOtherAssetsCurrent49.959.018.79.70.06.727.323.121.527.059.954.147.968.9
Percentage of Assets0.71.10.10.00.00.00.10.10.10.20.40.40.40.7
Percentage of Assets cnp:CercCorp2.33.70.30.10.00.10.50.50.50.81.41.20.81.6

cnp:HoustonElectric


Prepaid
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
Value2832473233364930414661505962
Percentage of PrepaidExpenseAndOtherAssetsCurrent5.85.033.828.330.630.030.419.222.719.131.831.835.325.7
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.20.20.30.3
Percentage of Assets cnp:HoustonElectric0.20.30.40.30.30.30.40.30.40.40.60.50.60.6

us-gaap:PrepaidExpenseAndOtherAssetsCurrent dei:LegalEntity, us-gaap:ConsolidatedEntities

cnp:HoustonElectric, us-gaap:VariableInterestEntityPrimaryBeneficiary


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value17161516191919
Percentage of PrepaidExpenseAndOtherAssetsCurrent3.52.510.814.217.615.811.8
Percentage of Assets0.00.00.00.00.10.10.1
Percentage of Assets cnp:HoustonElectric us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.00.00.0

us-gaap:PrepaidExpenseAndOtherAssetsCurrent us-gaap:ConsolidatedEntities

us-gaap:VariableInterestEntityPrimaryBeneficiary


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value17161516191919
Percentage of PrepaidExpenseAndOtherAssetsCurrent3.52.510.814.217.615.811.8
Percentage of Assets0.00.00.00.00.10.10.1
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.00.00.0

Assets Noncurrent

us-gaap:AssetsNoncurrent dei:LegalEntity

us-gaap:AssetsNoncurrent

cnp:EnableMidstreamPartners


Assets
Period End2021-03-312020-12-31
Value1131511348
Percentage of AssetsNoncurrent100.0100.0
Percentage of Assets31.533.9
Percentage of Assets cnp:EnableMidstreamPartners0.00.0

us-gaap:AssetsNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Assets
Period End2021-06-302020-12-312020-09-302020-06-302019-12-31
Value1128411348114021168711877
Percentage of AssetsNoncurrent0.0100.00.00.00.0
Percentage of Assets30.933.934.936.433.5
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.00.0

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3200432991325143182331349308303068530066295522901120267198611958519294190311858118374180701783117500172181690016650162641596715633153581497514674143681413813909136231859818377180101735017073168681659116426162351600514770
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets87.891.997.197.397.592.386.686.886.485.675.089.488.686.183.783.983.382.481.782.281.980.578.074.770.669.066.267.966.964.564.664.562.983.180.480.177.276.477.779.283.582.979.674.7

us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity

cnp:CercCorp


Property
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
Value75199070897286088404821081247892771075337431726071046888
Percentage of PropertyPlantAndEquipmentGross23.527.527.627.026.826.626.526.226.126.036.736.636.336.2
Percentage of Assets20.625.326.826.326.124.622.922.822.622.227.532.732.130.3
Percentage of Assets cnp:CercCorp72.487.6108.0110.7110.7100.796.399.598.793.490.599.473.768.1

cnp:HoustonElectric


Property
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
Value1429613889135931335413215130581282912621124571228712148119621181211496
Percentage of PropertyPlantAndEquipmentGross44.742.141.842.042.242.441.842.042.242.459.960.260.360.4
Percentage of Assets39.238.740.640.841.139.136.236.436.436.245.053.853.450.6
Percentage of Assets cnp:HoustonElectric119.0114.0120.1118.2119.1120.1113.9110.1108.5107.6115.6114.6113.3111.7

us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType

cnp:CercCorp, us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-31
Value892879337257
Percentage of PropertyPlantAndEquipmentGross27.525.935.8
Percentage of Assets26.722.426.9
Percentage of Assets cnp:CercCorp us-gaap:GasDistributionEquipment0.00.00.0

cnp:CercCorp, us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Property
Period End2020-12-312019-12-312018-12-31
Value445553
Percentage of PropertyPlantAndEquipmentGross0.10.20.3
Percentage of Assets0.10.20.2
Percentage of Assets cnp:CercCorp us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.0

cnp:HoustonElectric, us-gaap:ElectricDistribution


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value8225787675247178
Percentage of PropertyPlantAndEquipmentGross25.325.737.137.7
Percentage of Assets24.622.227.931.6
Percentage of Assets cnp:HoustonElectric us-gaap:ElectricDistribution0.00.00.00.0

cnp:HoustonElectric, us-gaap:ElectricTransmission


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value3686335830772767
Percentage of PropertyPlantAndEquipmentGross11.310.915.214.5
Percentage of Assets11.09.511.412.2
Percentage of Assets cnp:HoustonElectric us-gaap:ElectricTransmission0.00.00.00.0

cnp:HoustonElectric, us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value1682159515471551
Percentage of PropertyPlantAndEquipmentGross5.25.27.68.1
Percentage of Assets5.04.55.76.8
Percentage of Assets cnp:HoustonElectric us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType

us-gaap:ElectricGenerationEquipment


Property
Period End2020-12-312019-12-312018-12-31
Value192217800.0
Percentage of PropertyPlantAndEquipmentGross5.95.80.0
Percentage of Assets5.75.00.0
Percentage of Assets us-gaap:ElectricGenerationEquipment0.00.00.0

us-gaap:ElectricTransmissionAndDistribution


Property
Period End2020-12-312019-12-312018-12-312017-12-312011-12-312010-12-312009-12-31
Value15225143601214811496782775867325
Percentage of PropertyPlantAndEquipmentGross46.846.859.960.446.447.449.6
Percentage of Assets45.540.545.050.636.137.737.0
Percentage of Assets us-gaap:ElectricTransmissionAndDistribution0.00.00.00.00.00.00.0

us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312011-12-312010-12-312009-12-31
Value140221269572576735395936423436
Percentage of PropertyPlantAndEquipmentGross43.141.435.835.423.522.823.3
Percentage of Assets41.935.826.929.618.218.117.4
Percentage of Assets us-gaap:GasDistributionEquipment0.00.00.00.00.00.00.0

us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value13451397741698
Percentage of PropertyPlantAndEquipmentGross4.14.63.73.7
Percentage of Assets4.03.92.73.1
Percentage of Assets us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.00.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value990810252101521008810001985297409738962094996223620861886089597458815730561855245417532051825113507950564963485647704695460545454523443948904780467346114561446644334445437842733982
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.228.630.330.831.129.527.528.128.128.023.027.928.027.226.326.626.025.625.325.425.324.724.023.322.421.920.921.621.420.720.821.020.521.920.920.820.520.420.621.222.622.321.220.1

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity

cnp:CercCorp


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value20012466241424082358231222882330230622602205218521362036
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment20.224.123.823.923.623.523.523.924.023.835.435.234.534.1
Percentage of Assets5.56.97.27.47.36.96.56.76.76.78.29.89.79.0
Percentage of Assets cnp:CercCorp19.323.829.131.031.028.427.129.429.528.026.829.922.220.1

cnp:HoustonElectric


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value40263967393038753882384437973795376237433746374237413633
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment40.638.738.738.438.839.039.039.039.139.460.260.360.560.8
Percentage of Assets11.011.011.711.812.111.510.711.011.011.013.916.816.916.0
Percentage of Assets cnp:HoustonElectric33.532.634.734.335.035.433.733.132.832.835.735.935.935.3

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType

cnp:CercCorp, us-gaap:GasDistributionEquipment


Accumulated
Period End2020-12-312019-12-312018-12-31
Value239222082128
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment23.622.734.2
Percentage of Assets7.16.27.9
Percentage of Assets cnp:CercCorp us-gaap:GasDistributionEquipment0.00.00.0

cnp:CercCorp, us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Accumulated
Period End2020-12-312019-12-312018-12-31
Value222734
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment0.20.30.5
Percentage of Assets0.10.10.1
Percentage of Assets cnp:CercCorp us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.0

cnp:HoustonElectric, us-gaap:ElectricDistribution


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value2696258625532522
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment26.626.641.042.2
Percentage of Assets8.17.39.511.1
Percentage of Assets cnp:HoustonElectric us-gaap:ElectricDistribution0.00.00.00.0

cnp:HoustonElectric, us-gaap:ElectricTransmission


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value700674650620
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment6.96.910.410.4
Percentage of Assets2.11.92.42.7
Percentage of Assets cnp:HoustonElectric us-gaap:ElectricTransmission0.00.00.00.0

cnp:HoustonElectric, us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value534537543491
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment5.35.58.78.2
Percentage of Assets1.61.52.02.2
Percentage of Assets cnp:HoustonElectric us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.00.0

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:PropertyPlantAndEquipmentByType

us-gaap:ElectricGenerationEquipment


Accumulated
Period End2020-12-312019-12-312018-12-31
Value7546980.0
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment7.47.20.0
Percentage of Assets2.32.00.0
Percentage of Assets us-gaap:ElectricGenerationEquipment0.00.00.0

us-gaap:ElectricTransmissionAndDistribution


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312011-12-312010-12-312009-12-31
Value4785463437463633278428052737
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment47.147.660.260.862.365.668.7
Percentage of Assets14.313.113.916.012.813.913.8
Percentage of Assets us-gaap:ElectricTransmissionAndDistribution0.00.00.00.00.00.00.0

us-gaap:GasDistributionEquipment


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312011-12-312010-12-312009-12-31
Value40193731212819681069954825
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment39.638.334.232.923.922.320.7
Percentage of Assets12.010.57.98.74.94.74.2
Percentage of Assets us-gaap:GasDistributionEquipment0.00.00.00.00.00.00.0

us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value594602306338
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment5.96.24.95.7
Percentage of Assets1.81.71.11.5
Percentage of Assets us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.00.0

Amortization Of Intangible Assets

us-gaap:AmortizationOfIntangibleAssets

us-gaap:AmortizationOfIntangibleAssets


Amortization
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
Value1.00.00.01.05.07.03.09.03.02.02.03.08.02.01.02.0
Percentage of AmortizationOfIntangibleAssets100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AmortizationOfIntangibleAssets us-gaap:IncomeStatementLocation

cnp:Depreciationandamortizationexpense


Amortization
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
Value2.01.01.02.02.01.05.07.07.06.03.02.02.03.0
Percentage of AmortizationOfIntangibleAssets0.00.0100.00.00.0100.0100.0100.0233.366.7100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets cnp:Depreciationandamortizationexpense0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CostOfSales


Amortization
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1.00.00.01.05.07.03.07.00.00.00.0
Percentage of AmortizationOfIntangibleAssets100.00.00.0100.0100.0100.0100.077.80.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CostOfSales0.00.00.00.00.00.00.00.00.00.00.0

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value22096227392236221735213482097820945203281993219512140441365313397132051305712700126441245212307120831189811718115371118510911106701050210205997997639593938691841370813597133371273912512124021215811981118571173210788
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets60.663.366.866.566.462.859.158.758.357.652.061.460.658.957.457.457.456.856.456.856.655.854.151.448.347.145.346.345.543.943.943.542.461.359.559.356.756.057.158.060.960.558.354.6

us-gaap:PropertyPlantAndEquipmentNet dei:LegalEntity

cnp:CercCorp


Property
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
Value55186604655862006046589858365562540452735226507549684852
Percentage of PropertyPlantAndEquipmentNet25.029.029.328.528.328.127.927.427.127.037.237.237.137.2
Percentage of Assets15.118.419.619.018.817.716.516.115.815.619.322.822.521.3
Percentage of Assets cnp:CercCorp53.263.878.979.779.672.469.270.169.165.463.669.551.548.0

cnp:HoustonElectric


Property
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
Value102709922966394799333921490328826869585448402822080717863
Percentage of PropertyPlantAndEquipmentNet46.543.643.243.643.743.943.143.443.643.859.860.260.260.2
Percentage of Assets28.227.628.929.029.027.625.525.525.425.231.137.036.534.6
Percentage of Assets cnp:HoustonElectric85.581.485.483.984.184.880.277.075.874.880.078.877.476.4

us-gaap:PropertyPlantAndEquipmentNet dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType

cnp:CercCorp, us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-31
Value653657255129
Percentage of PropertyPlantAndEquipmentNet29.227.336.5
Percentage of Assets19.516.219.0
Percentage of Assets cnp:CercCorp us-gaap:GasDistributionEquipment0.00.00.0

cnp:CercCorp, us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Property
Period End2020-12-312019-12-312018-12-31
Value222819
Percentage of PropertyPlantAndEquipmentNet0.10.10.1
Percentage of Assets0.10.10.1
Percentage of Assets cnp:CercCorp us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.0

cnp:HoustonElectric, us-gaap:ElectricDistribution


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value5529529049714656
Percentage of PropertyPlantAndEquipmentNet24.725.335.435.7
Percentage of Assets16.514.918.420.5
Percentage of Assets cnp:HoustonElectric us-gaap:ElectricDistribution0.00.00.00.0

cnp:HoustonElectric, us-gaap:ElectricTransmission


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value2986268424272147
Percentage of PropertyPlantAndEquipmentNet13.412.817.316.4
Percentage of Assets8.97.69.09.4
Percentage of Assets cnp:HoustonElectric us-gaap:ElectricTransmission0.00.00.00.0

cnp:HoustonElectric, us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value1148105810041060
Percentage of PropertyPlantAndEquipmentNet5.15.17.18.1
Percentage of Assets3.43.03.74.7
Percentage of Assets cnp:HoustonElectric us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.00.0

us-gaap:PropertyPlantAndEquipmentNet us-gaap:PropertyPlantAndEquipmentByType

us-gaap:ElectricGenerationEquipment


Property
Period End2020-12-312019-12-312018-12-31
Value116810820.0
Percentage of PropertyPlantAndEquipmentNet5.25.20.0
Percentage of Assets3.53.10.0
Percentage of Assets us-gaap:ElectricGenerationEquipment0.00.00.0

us-gaap:ElectricTransmissionAndDistribution


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value10440972684027863
Percentage of PropertyPlantAndEquipmentNet46.746.459.860.2
Percentage of Assets31.227.431.134.6
Percentage of Assets us-gaap:ElectricTransmissionAndDistribution0.00.00.00.0

us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value10003896451294767
Percentage of PropertyPlantAndEquipmentNet44.742.836.536.5
Percentage of Assets29.925.319.021.0
Percentage of Assets us-gaap:GasDistributionEquipment0.00.00.00.0

us-gaap:OtherCapitalizedPropertyPlantAndEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value751795435360
Percentage of PropertyPlantAndEquipmentNet3.43.83.12.8
Percentage of Assets2.22.21.61.6
Percentage of Assets us-gaap:OtherCapitalizedPropertyPlantAndEquipment0.00.00.00.0

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value429446974697469746974697516451795179512986786786786786786786786786286286184084084084084084084084084084084084014681468146816961696169616961696169616961696
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets11.813.114.014.414.614.114.615.015.115.13.23.93.93.93.83.93.94.03.94.04.14.03.93.93.73.73.63.83.83.83.83.93.96.66.46.57.57.67.88.18.68.78.48.6

us-gaap:Goodwill dei:LegalEntity

cnp:CercCorp


Goodwilldei:
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
Value611757757757757757819867867867867867867867
Percentage of Goodwill14.216.116.116.116.116.115.916.716.716.9100.0100.0100.0100.0
Percentage of Assets1.72.12.32.32.42.32.32.52.52.63.23.93.93.8
Percentage of Assets cnp:CercCorp5.97.39.19.710.09.39.710.911.110.810.611.99.08.6

us-gaap:Goodwill us-gaap:StatementBusinessSegments

cnp:Electric


Goodwillus-gaap:
Period End2021-06-302021-03-312020-12-312019-12-31
Value9369369361121
Percentage of Goodwill21.819.919.921.7
Percentage of Assets2.62.62.83.2
Percentage of Assets cnp:Electric0.00.00.00.0

cnp:IndianaElectricIntegrated


Goodwillus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value9369369361121100810080.00.0
Percentage of Goodwill19.919.919.921.719.519.50.00.0
Percentage of Assets2.92.92.83.22.92.90.00.0
Percentage of Assets cnp:IndianaElectricIntegrated0.00.00.00.00.00.00.00.0

cnp:NaturalGasDistribution


Goodwillus-gaap:
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value331233123312331232753275746746746746746746746746746746746746746746746746746746746746746746746746746746746746746746746746
Percentage of Goodwill70.570.570.564.163.263.214.586.086.086.086.086.086.086.086.086.586.586.688.888.888.888.888.888.888.888.888.888.888.888.850.850.850.844.044.044.044.044.0
Percentage of Assets10.110.39.99.39.59.62.22.83.43.43.33.33.43.43.43.43.53.63.63.53.43.33.33.23.43.43.43.43.53.43.33.33.33.33.33.43.63.7
Percentage of Assets cnp:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.014.615.00.015.915.815.616.316.616.516.117.016.3

cnp:NaturalGasSegment


Goodwillus-gaap:
Period End2021-06-302021-03-312020-12-31
Value292033233323
Percentage of Goodwill68.070.770.7
Percentage of Assets8.09.39.9
Percentage of Assets cnp:NaturalGasSegment0.00.00.0

us-gaap:CorporateAndOther


Goodwillus-gaap:
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-31
Value43843844944944944943143111111111111111111111111111111111111111111111111111111111
Percentage of Goodwill9.39.39.69.69.68.78.38.30.21.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.31.30.70.70.70.6
Percentage of Assets1.21.31.41.41.31.31.21.30.00.00.00.00.00.00.00.00.10.10.10.10.10.10.10.00.00.00.00.10.00.10.10.10.00.00.00.1
Percentage of Assets us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.30.40.00.40.40.40.50.5

Finite Lived Intangible Assets Net

us-gaap:FiniteLivedIntangibleAssetsNet

us-gaap:FiniteLivedIntangibleAssetsNet


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value474950525456321356370460656769717449
Percentage of FiniteLivedIntangibleAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.20.20.20.91.01.11.40.20.30.30.30.30.2

us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass

cnp:Operationandmaintenanceagreements


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value111111111111111111470.0
Percentage of FiniteLivedIntangibleAssetsNet23.422.422.021.220.419.63.43.13.010.20.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.10.0
Percentage of Assets cnp:Operationandmaintenanceagreements0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CustomerRelationships


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value232425262728243266270284596061636545
Percentage of FiniteLivedIntangibleAssetsNet48.949.050.050.050.050.075.774.773.061.790.889.688.488.787.891.8
Percentage of Assets0.10.10.10.10.10.10.70.80.80.80.20.30.30.30.30.2
Percentage of Assets us-gaap:CustomerRelationships0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OrderOrProductionBacklog


Finite
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1.01.01.04.010.017460.0
Percentage of FiniteLivedIntangibleAssetsNet1.91.91.81.22.84.610.00.0
Percentage of Assets0.00.00.00.00.00.00.10.0
Percentage of Assets us-gaap:OrderOrProductionBacklog0.00.00.00.00.00.00.00.0

us-gaap:OtherIntangibleAssets


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value1.01.01.01.01.01.010.010.012125.05.06.06.07.01.0
Percentage of FiniteLivedIntangibleAssetsNet2.12.02.01.91.91.83.12.83.22.67.77.58.78.59.52.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:OtherIntangibleAssets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TradeNames


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value121313131415535859700.0
Percentage of FiniteLivedIntangibleAssetsNet25.526.526.025.025.926.816.516.315.915.20.0
Percentage of Assets0.00.00.00.00.00.00.10.20.20.20.0
Percentage of Assets us-gaap:TradeNames0.00.00.00.00.00.00.00.00.00.00.0

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
Value3163677267
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0
Percentage of Assets0.10.20.20.20.2

us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity

cnp:CercCorp


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value1924252626
Percentage of OperatingLeaseRightOfUseAsset61.338.137.336.138.8
Percentage of Assets0.10.10.10.10.1
Percentage of Assets cnp:CercCorp0.20.30.30.30.3

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value225240252226235223216273273286223190216194191194207204173134147109146148151144147150161159162140187197197183193159157154158157172230
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.70.80.70.70.70.60.80.80.80.80.91.00.90.80.90.90.90.80.60.70.50.70.70.70.60.60.70.70.70.70.60.90.90.90.80.90.70.70.70.80.80.91.2

us-gaap:OtherAssetsNoncurrent dei:LegalEntity

cnp:CercCorp


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3848664850401201731541651329597104
Percentage of OtherAssetsNoncurrent16.920.026.221.221.317.955.663.456.457.759.250.044.954.5
Percentage of Assets0.10.10.20.10.20.10.30.50.50.50.50.40.40.5
Percentage of Assets cnp:CercCorp0.40.50.80.60.70.51.42.22.02.01.61.31.01.0

cnp:HoustonElectric


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3338362634292520313432203529
Percentage of OtherAssetsNoncurrent14.715.814.311.514.513.011.67.311.411.914.310.516.215.2
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.20.1
Percentage of Assets cnp:HoustonElectric0.30.30.30.20.30.30.20.20.30.30.30.20.30.3

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value797797853658670739113888893611811240708706712963657631634657422407378483367367476716441519802689364404510561371331366560417394449667648
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.22.22.52.02.12.23.22.62.73.54.63.23.23.24.23.02.92.93.02.01.91.82.31.71.62.13.12.02.43.63.21.71.92.32.51.71.51.62.62.02.02.33.33.3

us-gaap:AccountsPayableCurrent dei:LegalEntity

cnp:CercCorp


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value226273296191204235557393406570856429434669
Percentage of AccountsPayableCurrent28.434.334.729.030.431.848.944.343.448.369.060.661.569.5
Percentage of Assets0.60.80.90.60.60.71.61.11.21.73.21.92.02.9
Percentage of Assets cnp:CercCorp2.22.63.62.52.72.96.65.05.27.110.45.94.56.6

cnp:HoustonElectric


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value413333281256234259268232226238262220208243
Percentage of AccountsPayableCurrent51.841.832.938.934.935.023.626.124.120.221.131.129.525.2
Percentage of Assets1.10.90.80.80.70.80.80.70.70.71.01.00.91.1
Percentage of Assets cnp:HoustonElectric3.42.72.52.32.12.42.42.02.02.12.52.12.02.4

Contract With Customer Liability Current

us-gaap:ContractWithCustomerLiabilityCurrent

us-gaap:ContractWithCustomerLiabilityCurrent


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value109120119120124124124
Percentage of ContractWithCustomerLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.30.30.40.40.40.40.3

us-gaap:ContractWithCustomerLiabilityCurrent dei:LegalEntity

cnp:CercCorp


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value65767676767574
Percentage of ContractWithCustomerLiabilityCurrent59.663.363.963.361.360.559.7
Percentage of Assets0.20.20.20.20.20.20.2
Percentage of Assets cnp:CercCorp0.60.70.91.01.00.90.9

Debt Current

us-gaap:DebtCurrent

us-gaap:DebtCurrent


Debt
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value19198684826451060913848540
Percentage of DebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.72.41.82.84.94.33.72.5

us-gaap:DebtCurrent dei:LegalEntity

cnp:CercCorp


Debt
Period End2020-12-312019-12-312018-12-312017-12-31
Value240.00.039
Percentage of DebtCurrent1.30.00.06.0
Percentage of Assets0.10.00.00.2
Percentage of Assets cnp:CercCorp0.30.00.00.4

cnp:HoustonElectric


Debt
Period End2020-12-312019-12-312018-12-312017-12-31
Value613231458434
Percentage of DebtCurrent31.926.695.067.3
Percentage of Assets1.80.71.71.9
Percentage of Assets cnp:HoustonElectric5.42.14.44.2

Dividends Payable Current

us-gaap:DividendsPayableCurrent

us-gaap:DividendsPayableCurrent


Dividends
Period End2020-12-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value1360.00.00.00.01870.00.00.01200.0
Percentage of DividendsPayableCurrent100.00.00.00.00.0100.00.00.00.0100.00.0
Percentage of Assets0.40.00.00.00.00.70.00.00.00.50.0

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value33694326482538304309404238883434299631393302258128422616306932213038264230802398224125342467319131253187347530083026305930192595267531263575336432062735259323192361220126203038
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets9.212.014.411.713.412.111.09.98.89.312.211.612.911.713.514.613.812.014.111.310.712.111.614.713.814.115.013.613.813.713.812.012.414.015.615.014.312.211.911.112.011.213.015.4

us-gaap:LiabilitiesCurrent dei:LegalEntity

cnp:CercCorp


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value102165472660611701471103879977497913408468091659
Percentage of LiabilitiesCurrent30.315.115.015.827.236.426.723.325.831.240.632.828.554.1
Percentage of Assets2.81.82.21.93.64.42.92.32.32.95.03.83.77.3
Percentage of Assets cnp:CercCorp9.86.38.77.815.418.012.310.19.912.116.311.68.416.4

cnp:EnableMidstreamPartners


Liabilities
Period End2021-03-312020-12-31
Value1334582
Percentage of LiabilitiesCurrent30.812.1
Percentage of Assets3.71.7
Percentage of Assets cnp:EnableMidstreamPartners0.00.0

cnp:HoustonElectric


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value101211571336125811658288307468528191090103110041082
Percentage of LiabilitiesCurrent30.026.727.732.827.020.521.321.728.426.133.039.935.335.3
Percentage of Assets2.83.24.03.83.62.52.32.22.52.44.04.64.54.8
Percentage of Assets cnp:HoustonElectric8.49.511.811.110.57.67.46.57.47.210.49.99.610.5

us-gaap:LiabilitiesCurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Liabilities
Period End2021-06-302020-12-312020-09-302020-06-302019-12-31
Value1317582644290780
Percentage of LiabilitiesCurrent39.112.116.86.720.1
Percentage of Assets3.61.72.00.92.2
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.00.0

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity

us-gaap:OperatingLeaseLiabilityCurrent

cnp:CercCorp


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value3.04.04.05.04.0
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0
Percentage of Assets cnp:CercCorp0.00.00.10.10.0

us-gaap:OperatingLeaseLiabilityCurrent us-gaap:BalanceSheetLocation

us-gaap:OtherCurrentLiabilities


Operating
Period End2020-12-312019-12-31
Value6.07.0
Percentage of OperatingLeaseLiabilityCurrent200.0175.0
Percentage of Assets0.00.0
Percentage of Assets us-gaap:OtherCurrentLiabilities0.00.0

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value336344432429325300414375343338341392344343368339269267325353334317343384385394383373355365402343358347380347327281366319322350438445
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.91.01.31.31.00.91.21.11.01.01.31.81.61.51.61.51.21.21.51.71.61.51.61.81.71.71.71.71.61.61.81.61.71.61.71.51.51.31.71.51.61.82.22.3

us-gaap:OtherLiabilitiesCurrent dei:LegalEntity

cnp:CercCorp


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value127137178165133134191143132136137171152137
Percentage of OtherLiabilitiesCurrent37.839.841.238.540.944.746.138.138.540.240.243.644.237.2
Percentage of Assets0.30.40.50.50.40.40.50.40.40.40.50.80.70.6
Percentage of Assets cnp:CercCorp1.21.32.12.11.81.62.31.81.71.71.72.31.61.4

cnp:HoustonElectric


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value1141151171279578636973768911193120
Percentage of OtherLiabilitiesCurrent33.933.427.129.629.226.015.218.421.322.526.128.327.032.6
Percentage of Assets0.30.30.30.40.30.20.20.20.20.20.30.50.40.5
Percentage of Assets cnp:HoustonElectric0.90.91.01.10.90.70.60.60.60.70.81.10.91.2

Taxes Payable Current

us-gaap:TaxesPayableCurrent

us-gaap:TaxesPayableCurrent


Taxes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value203229265212241177241193158214204152103176181199153108172134921011581289014216113912922018413095123160171132164207184139140156148
Percentage of TaxesPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.60.80.60.70.50.70.60.50.60.80.70.50.80.80.90.70.50.80.60.40.50.70.60.40.60.70.60.61.00.80.60.40.50.70.80.60.71.00.90.70.70.80.7

us-gaap:TaxesPayableCurrent dei:LegalEntity

cnp:CercCorp


Taxes
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
Value5590746852808466518182644875
Percentage of TaxesPayableCurrent27.139.327.932.121.645.234.934.232.337.940.242.146.641.4
Percentage of Assets0.20.30.20.20.20.20.20.20.10.20.30.30.20.3
Percentage of Assets cnp:CercCorp0.50.90.90.90.71.01.00.80.71.01.00.90.50.7

cnp:HoustonElectric


Taxes
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
Value1491031581551106112310763651158861116
Percentage of TaxesPayableCurrent73.445.059.673.145.634.551.055.439.930.456.457.959.264.1
Percentage of Assets0.40.30.50.50.30.20.30.30.20.20.40.40.30.5
Percentage of Assets cnp:HoustonElectric1.20.81.41.41.00.61.10.90.50.61.10.80.61.1

Liabilities Noncurrent

us-gaap:LiabilitiesNoncurrent dei:LegalEntity

us-gaap:LiabilitiesNoncurrent

cnp:EnableMidstreamPartners


Liabilities
Period End2021-03-312020-12-31
Value32494052
Percentage of LiabilitiesNoncurrent100.0100.0
Percentage of Assets9.012.1
Percentage of Assets cnp:EnableMidstreamPartners0.00.0

us-gaap:LiabilitiesNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Liabilities
Period End2021-06-302020-12-312020-09-302020-06-302019-12-31
Value32494052405544544077
Percentage of LiabilitiesNoncurrent0.0100.00.00.00.0
Percentage of Assets8.912.112.413.911.5
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.00.0

Long Term Debt

us-gaap:LongTermDebt

us-gaap:LongTermDebt


Long
Period End2020-12-312019-12-312018-12-312017-12-31
Value115211424486828195
Percentage of LongTermDebt100.0100.0100.0100.0
Percentage of Assets34.440.232.136.0

us-gaap:LongTermDebt dei:LegalEntity

cnp:CercCorp


Long
Period End2020-12-312019-12-312018-12-312017-12-31
Value2428254623712457
Percentage of LongTermDebt21.117.927.330.0
Percentage of Assets7.37.28.810.8
Percentage of Assets cnp:CercCorp29.230.228.924.3

cnp:HoustonElectric


Long
Period End2020-12-312019-12-312018-12-312017-12-31
Value4406471942584319
Percentage of LongTermDebt38.233.149.052.7
Percentage of Assets13.213.315.819.0
Percentage of Assets cnp:HoustonElectric38.941.940.542.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value158531404811521119461093713830142441401414121137598682725277608176819575317587789275327736778073547901766276147767800977977755805678177758791981308357841585839005864184978510873290019119
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets43.539.134.436.534.041.440.240.541.340.632.132.635.136.536.034.034.436.034.536.337.035.037.035.233.734.334.535.435.436.235.736.036.636.336.537.438.240.339.840.643.244.644.846.1

us-gaap:LongTermDebtNoncurrent dei:LegalEntity

cnp:CercCorp


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value43434349242825821813178425462477239723842371225727222457
Percentage of LongTermDebtNoncurrent27.431.021.121.616.612.917.917.717.017.327.331.135.130.0
Percentage of Assets11.912.17.37.95.65.37.27.27.07.08.810.212.310.8
Percentage of Assets cnp:CercCorp41.842.029.233.223.921.930.231.230.729.628.930.928.224.3

cnp:HoustonElectric


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value53805456440644794507468447194789481648844258432644734319
Percentage of LongTermDebtNoncurrent33.938.838.237.541.233.933.134.234.135.549.059.757.652.7
Percentage of Assets14.815.213.213.714.014.013.313.814.114.415.819.520.219.0
Percentage of Assets cnp:HoustonElectric44.844.838.939.740.643.141.941.842.042.840.541.542.942.0

Deferred Finance Costs Noncurrent Net

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

us-gaap:DeferredFinanceCostsNoncurrentNet

cnp:HoustonElectric, cnp:UnamortizedDebtIssuanceCosts


Deferred
Period End2020-12-312019-12-31
Value2827
Percentage of DeferredFinanceCostsNoncurrentNet100.0100.0
Percentage of Assets0.10.1
Percentage of Assets cnp:HoustonElectric cnp:UnamortizedDebtIssuanceCosts0.00.0

us-gaap:DeferredFinanceCostsNoncurrentNet us-gaap:LongtermDebtType

cnp:UnamortizedDebtIssuanceCosts


Deferred
Period End2020-12-312019-12-31
Value1722
Percentage of DeferredFinanceCostsNoncurrentNet60.781.5
Percentage of Assets0.10.1
Percentage of Assets cnp:UnamortizedDebtIssuanceCosts0.00.0

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value3698368736033575349135623928
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets10.110.310.810.910.910.711.1

us-gaap:DeferredIncomeTaxLiabilitiesNet dei:LegalEntity

cnp:CercCorp


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value619632584509507498470
Percentage of DeferredIncomeTaxLiabilitiesNet16.717.116.214.214.514.012.0
Percentage of Assets1.71.81.71.61.61.51.3
Percentage of Assets cnp:CercCorp6.06.17.06.56.76.15.6

cnp:HoustonElectric


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value1069105110411029103610361030
Percentage of DeferredIncomeTaxLiabilitiesNet28.928.528.928.829.729.126.2
Percentage of Assets2.92.93.13.13.23.12.9
Percentage of Assets cnp:HoustonElectric8.98.69.29.19.39.59.1

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value6656756806917717467548128728887967227237237858869089169139099049099048899259289537187738028021052110211371143994102010661065842903905906861
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.81.92.02.12.42.22.12.32.62.62.93.23.33.23.54.04.14.24.24.34.34.34.24.14.14.14.13.33.53.63.74.95.15.15.04.44.54.84.94.04.64.64.54.4

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent dei:LegalEntity

cnp:CercCorp


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value8383838484808395949493989897
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent12.512.312.212.210.910.711.011.710.810.611.713.613.612.4
Percentage of Assets0.20.20.20.30.30.20.20.30.30.30.30.40.40.4
Percentage of Assets cnp:CercCorp0.80.81.01.11.11.01.01.21.21.21.11.31.01.0

cnp:HoustonElectric


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value7575757273727584878891142143146
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent11.311.111.010.49.59.79.910.310.09.911.419.719.818.6
Percentage of Assets0.20.20.20.20.20.20.20.20.30.30.30.60.60.6
Percentage of Assets cnp:HoustonElectric0.60.60.70.60.70.70.70.70.80.80.91.41.41.4

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

cnp:CercCorp, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value74728279
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent10.99.510.310.1
Percentage of Assets0.20.20.30.3
Percentage of Assets cnp:CercCorp us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.0

cnp:HoustonElectric, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value626177132
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent9.18.19.716.8
Percentage of Assets0.20.20.30.6
Percentage of Assets cnp:HoustonElectric us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.0

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value223220211260264
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent32.829.226.533.128.9
Percentage of Assets0.70.60.81.11.2
Percentage of Assets us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.00.0

us-gaap:PensionPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value364440490417534
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent53.558.461.653.158.5
Percentage of Assets1.11.21.81.82.4
Percentage of Assets us-gaap:PensionPlansDefinedBenefit0.00.00.00.00.0

Minority Interest

us-gaap:MinorityInterest us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:MinorityInterest

cnp:EnableMidstreamPartners


Minority
Period End2021-06-302020-12-312020-09-302020-06-302019-12-31
Value2526262737
Percentage of MinorityInterest100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.1
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.00.0

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value94610331019789774751763672653609402433412361357284292287278282279276273259250253251207206203205251232258247276263239305236407473438361
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.62.93.02.42.42.22.21.91.91.81.51.91.91.61.61.31.31.31.31.31.31.31.31.21.11.11.10.90.90.90.91.21.11.21.11.21.21.11.41.12.12.42.21.8

us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity

cnp:CercCorp


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value582678694437430411428381357362329350352297
Percentage of OtherLiabilitiesNoncurrent61.565.668.155.455.654.756.156.754.759.481.880.885.483.2
Percentage of Assets1.61.92.11.31.31.21.21.11.01.11.21.61.61.3
Percentage of Assets cnp:CercCorp5.66.58.45.65.75.05.14.84.64.54.04.83.72.9

cnp:HoustonElectric


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value10095958785806961696865795654
Percentage of OtherLiabilitiesNoncurrent10.69.29.311.011.010.79.09.110.611.216.218.213.615.1
Percentage of Assets0.30.30.30.30.30.20.20.20.20.20.20.40.30.2
Percentage of Assets cnp:HoustonElectric0.80.80.80.80.80.70.60.50.60.60.60.80.50.5

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity

us-gaap:OperatingLeaseLiabilityNoncurrent

cnp:CercCorp


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value1820212122
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.1
Percentage of Assets cnp:CercCorp0.20.20.30.30.3

us-gaap:OperatingLeaseLiabilityNoncurrent us-gaap:BalanceSheetLocation

us-gaap:OtherNoncurrentLiabilities


Operating
Period End2020-12-312019-12-31
Value2624
Percentage of OperatingLeaseLiabilityNoncurrent144.4120.0
Percentage of Assets0.10.1
Percentage of Assets us-gaap:OtherNoncurrentLiabilities0.00.0

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
Value6.016151512
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo dei:LegalEntity

cnp:CercCorp


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value4.04.05.04.04.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo66.725.033.326.733.3
Percentage of Assets0.00.00.00.00.0
Percentage of Assets cnp:CercCorp0.00.00.10.10.0

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
Value6000000.09000000.09000000.08000000.07000000.0
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
Value4000000.07000000.07000000.07000000.06000000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value10.01212129.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive dei:LegalEntity

cnp:CercCorp


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value7.09.09.09.09.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive70.075.075.075.0100.0
Percentage of Assets0.00.00.00.00.0
Percentage of Assets cnp:CercCorp0.10.10.10.10.1

Operating Lease Liability

us-gaap:OperatingLeaseLiability dei:LegalEntity, us-gaap:BalanceSheetLocation

us-gaap:OperatingLeaseLiability

cnp:CercCorp, us-gaap:OtherLiabilities


Operating
Period End2020-12-312019-12-31
Value2118
Percentage of OperatingLeaseLiability100.0100.0
Percentage of Assets0.10.1
Percentage of Assets cnp:CercCorp us-gaap:OtherLiabilities0.00.0

us-gaap:OperatingLeaseLiability us-gaap:BalanceSheetLocation

us-gaap:OtherLiabilities


Operating
Period End2020-12-312019-12-31
Value3231
Percentage of OperatingLeaseLiability152.4172.2
Percentage of Assets0.10.1
Percentage of Assets us-gaap:OtherLiabilities0.00.0

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
Value3769748074
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0100.0100.0100.0100.0
Percentage of Assets0.10.20.20.20.2

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue dei:LegalEntity

cnp:CercCorp


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value2428293031
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue64.940.639.237.541.9
Percentage of Assets0.10.10.10.10.1
Percentage of Assets cnp:CercCorp0.30.30.40.40.4

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
Value5000000.06000000.07000000.08000000.07000000.0
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount dei:LegalEntity

cnp:CercCorp


Lessee
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value3000000.04000000.04000000.04000000.05000000.0
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount60.066.757.150.071.4
Percentage of Assets0.00.00.00.00.0
Percentage of Assets cnp:CercCorp0.00.00.10.10.1

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value887087168348838883926970835983468257821680585508467048574688361835633537346034723397350634614058455045744548447344254414432942614191437143014257433242864222420733133266319826392022
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.324.324.925.626.120.923.624.124.224.229.824.821.121.720.616.316.216.115.916.316.216.716.218.620.120.219.620.320.219.819.819.719.419.518.818.919.319.219.520.116.816.715.913.310.3

us-gaap:StockholdersEquity dei:LegalEntity

cnp:CercCorp


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value2776271825672345235726712641248325062561244321373063315131082922
Percentage of StockholdersEquity31.331.230.728.028.138.331.629.830.431.230.338.865.664.966.384.5
Percentage of Assets7.67.67.77.27.38.07.57.27.37.69.09.613.914.113.713.4
Percentage of Assets cnp:CercCorp26.726.230.930.131.032.831.331.332.131.829.729.331.80.030.731.7

cnp:HoustonElectric


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3267316431113086298128993251348333583274268225492464239423692117
Percentage of StockholdersEquity36.836.337.336.835.541.638.941.740.739.833.346.352.849.350.561.2
Percentage of Assets9.08.89.39.49.38.79.210.19.89.79.911.511.110.710.49.7
Percentage of Assets cnp:HoustonElectric27.226.027.527.326.926.728.930.429.328.725.524.423.60.023.00.0

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

cnp:CercCorp, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value10.010.010.010.010.010.010.05.05.05.05.06.06.06.06.03.09.0
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.3
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets cnp:CercCorp us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:CercCorp, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value20462046204618291829211621162015201520152015166825282527252824892417
Percentage of StockholdersEquity23.123.524.521.821.830.425.324.124.424.525.030.354.152.053.971.969.8
Percentage of Assets5.65.76.15.65.76.36.05.85.95.97.57.511.411.311.111.411.3
Percentage of Assets cnp:CercCorp us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:CercCorp, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value720662511506518545515463486541423463529618574430828
Percentage of StockholdersEquity8.17.66.16.06.27.86.25.55.96.65.28.411.312.712.212.423.9
Percentage of Assets2.01.81.51.51.61.61.51.31.41.61.62.12.42.82.52.03.9
Percentage of Assets cnp:CercCorp us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value25482548254824862486248624862486248624861896169616971697169616961322
Percentage of StockholdersEquity28.729.230.529.629.635.729.729.830.130.323.530.836.334.936.249.038.2
Percentage of Assets7.07.17.67.67.77.47.07.27.37.37.07.67.77.67.57.86.2
Percentage of Assets cnp:HoustonElectric us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value7196165636004954287801012887803800846763693673420279
Percentage of StockholdersEquity8.17.16.77.25.96.19.312.110.79.89.915.416.314.314.412.18.1
Percentage of Assets2.01.71.71.81.51.32.22.92.62.43.03.83.53.13.01.91.3
Percentage of Assets cnp:HoustonElectric us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Stockholders
Period End2020-12-312020-09-302020-06-302019-12-31
Value6713669569377013
Percentage of StockholdersEquity80.479.882.783.9
Percentage of Assets20.120.521.619.8
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-85.0-87.0-90.0-82.0-84.0-100.0-98.0-107.0-105.0-107.0-108.0-58.0-62.0-63.0-68.0-71.0-66.0-86.0-90.0-135.0-133.0-117.0-124.0-131.0
Percentage of StockholdersEquity-1.0-1.0-1.1-1.0-1.0-1.4-1.2-1.3-1.3-1.3-1.3-1.1-1.3-1.3-1.5-2.1-1.9-1.9-2.1-3.1-3.2-3.7-4.7-6.5
Percentage of Assets-0.2-0.2-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.4-0.6-0.6-0.6-0.6-0.7
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 End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value7553691669146805680160866080607260656060607242214215420842094195418041694157413041204100367131583046
Percentage of StockholdersEquity85.279.382.881.181.087.372.772.873.573.875.476.690.386.689.8121.2120.891.796.096.097.6128.2139.1156.20.0
Percentage of Assets20.719.320.720.821.218.217.217.517.717.922.519.019.118.818.519.219.618.019.018.119.020.418.616.10.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value6.06.06.05.05.05.05.05.05.05.05.04.04.04.04.04.04.04.04.04.04.04.04.03.03.0
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.10.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value173923632363245624411740174017401740174017407900.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of StockholdersEquity19.627.128.329.329.125.020.820.821.121.221.614.30.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets4.86.67.17.57.65.24.95.05.15.16.43.60.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-343.0-482.0-845.0-796.0-771.0-761.0632636552518349551513708543-668.0-657.0461258302231-789.0-912.0-1008.0-1194.0
Percentage of StockholdersEquity-3.9-5.5-10.1-9.5-9.2-10.97.67.66.76.34.310.011.014.611.6-19.3-19.010.16.07.05.5-24.7-34.6-49.90.0
Percentage of Assets-0.9-1.3-2.5-2.4-2.4-2.31.81.81.61.51.32.52.33.22.4-3.1-3.12.01.21.31.1-3.9-4.6-5.10.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value6000000.06000000.06000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Additional Paid In Capital

us-gaap:AdditionalPaidInCapital

us-gaap:AdditionalPaidInCapital


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value7553691669146805680160866080607260656060607242214215420842094204420041954195419041864180418041764172416841694167416241584157415141464139413041234125412241204114411141024100
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets20.719.320.720.821.218.217.217.517.717.922.519.019.118.818.519.019.119.119.219.719.919.919.619.218.518.418.018.919.018.719.019.219.118.518.118.318.418.419.019.620.920.920.4

us-gaap:AdditionalPaidInCapital dei:LegalEntity

cnp:CercCorp


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value20462046204618291829211621162015201520152015166825282528
Percentage of AdditionalPaidInCapital27.129.629.626.926.934.834.833.233.233.333.239.560.060.1
Percentage of Assets5.65.76.15.65.76.36.05.85.95.97.57.511.411.1
Percentage of Assets cnp:CercCorp19.719.824.623.524.126.025.125.425.825.024.522.826.225.0

cnp:HoustonElectric


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value25482548254824862486248624862486248624861896169616971696
Percentage of AdditionalPaidInCapital33.736.836.936.536.640.840.940.941.041.031.240.240.340.3
Percentage of Assets7.07.17.67.67.77.47.07.27.37.37.07.67.77.5
Percentage of Assets cnp:HoustonElectric21.220.922.522.022.422.922.121.721.721.818.016.316.316.5

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value-343.0-482.0-845.0-796.0-771.0-761.0632636552518349551513708543-518.0-571.0-591.0-668.0-658.0-726.0-613.0-657.0-41.0456486461387346341258233171360302255331291231199-690.0-725.0-789.0
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.9-1.3-2.5-2.4-2.4-2.31.81.81.61.51.32.52.33.22.4-2.3-2.6-2.7-3.1-3.1-3.5-2.9-3.1-0.22.02.12.01.81.61.51.21.10.81.61.31.11.51.31.10.9-3.5-3.7-3.9

us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity

cnp:CercCorp


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value720662511506518545515463486541423463529574
Percentage of RetainedEarningsAccumulatedDeficit-209.9-137.3-60.5-63.6-67.2-71.681.572.888.0104.4121.284.0103.1105.7
Percentage of Assets2.01.81.51.51.61.61.51.31.41.61.62.12.42.5
Percentage of Assets cnp:CercCorp6.96.46.26.56.86.76.15.86.26.75.16.35.55.7

cnp:HoustonElectric


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value7196165636004954287801012887803800846763673
Percentage of RetainedEarningsAccumulatedDeficit-209.6-127.8-66.6-75.4-64.2-56.2123.4159.1160.7155.0229.2153.5148.7123.9
Percentage of Assets2.01.71.71.81.51.32.22.92.62.43.03.83.53.0
Percentage of Assets cnp:HoustonElectric6.05.15.05.34.53.96.98.87.77.07.68.17.36.5

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value-85000000.0-87000000.0-90000000.0-82000000.0-84000000.0-100000000.0-98000000.0-107000000.0-105000000.0-107000000.0-108000000.0-58000000.0-62000000.0-63000000.0-68000000.0-72000000.0-70000000.0-71000000.0-71000000.0-64000000.0-67000000.0-65000000.0-66000000.0-81000000.0-82000000.0-84000000.0-86000000.0-85000000.0-87000000.0-89000000.0-90000000.0-127000000.0-130000000.0-132000000.0-135000000.0-125000000.0-128000000.0-131000000.0-133000000.0-110000000.0-112000000.0-115000000.0-117000000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.2-0.2-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.5-0.6-0.6-0.6

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

cnp:CercCorp


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value10000000.010000000.010000000.010000000.010000000.010000000.010000000.05000000.05000000.05000000.05000000.06000000.06000000.06000000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-11.8-11.5-11.1-12.2-11.9-10.0-10.2-4.7-4.8-4.7-4.6-10.3-9.7-8.8
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets cnp:CercCorp0.10.10.10.10.10.10.10.10.10.10.10.10.10.1

Minority Interest

us-gaap:MinorityInterest us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:MinorityInterest

cnp:EnableMidstreamPartners


Minority
Period End2021-06-302020-12-312020-09-302020-06-302019-12-31
Value2526262737
Percentage of MinorityInterest100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.1
Percentage of Assets cnp:EnableMidstreamPartners0.00.00.00.00.0

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:AdditionalPaidInCapital


Stock
Period End2021-06-302020-09-302020-06-30
Value624-1.0673
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.0
Percentage of Assets0.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.0

us-gaap:PreferredStock


Stock
Period End2020-09-302020-06-30
Value15701
Percentage of StockIssuedDuringPeriodValueNewIssues-1500.0104.2
Percentage of Assets0.00.0
Percentage of Assets us-gaap:PreferredStock0.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value605-1681.0556258519662552512303271457586609484393351360317257533481452503424439312510627403165383435
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax35.3-66.227.316.033.130.917.124.514.710.715.142.342.022.814.926.126.918.513.622.322.526.533.020.320.516.627.824.219.28.621.814.4

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value224-1787.08359206381-47.064201248-36.0104360386-34.034
Percentage of NetCashProvidedByUsedInOperatingActivities37.0106.314.922.939.757.6-8.512.566.391.5-7.917.759.179.8-8.79.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.1-70.34.13.713.217.8-1.53.19.89.8-1.27.524.818.2-1.32.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp40.10.00.014.143.638.7-4.813.433.718.1-3.421.761.328.3-3.56.9

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2074734727417510332335517466327345263180338288
Percentage of NetCashProvidedByUsedInOperatingActivities34.2-2.862.4106.233.715.658.569.357.424.471.658.943.237.286.082.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax12.11.817.117.011.24.810.017.08.52.610.824.918.28.512.821.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric26.20.00.00.024.20.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-772.0-604.0-582.0-540.0511-654.0-646.0-626.0-610.0-6539.0-533.0-407.064-331.0-360.0-257.0-268.0-372.0-351.0-274.0-394.0-552.0-365.0-292.0-358.0-276.0-264.0-308.0-406.0-295.0-416.0-303.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-45.0-23.8-28.6-33.532.6-30.5-20.0-29.9-29.7-257.5-17.6-29.44.4-15.6-13.6-19.1-20.0-21.7-18.5-11.5-18.4-32.4-23.9-14.0-16.7-14.7-14.4-11.9-19.4-15.5-23.7-10.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-184.0-131.0-113.0-242.080-177.0-147.0-129.0-136.0-250.0-338.0-162.0-100.0-97.0-66.0-75.0
Percentage of NetCashProvidedByUsedInInvestingActivities23.821.719.444.815.727.122.820.622.33.863.439.8-156.229.318.329.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-10.7-5.2-5.6-15.05.1-8.3-4.6-6.2-6.6-9.8-11.1-11.7-6.9-4.6-2.5-5.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-33.00.00.0-58.016.9-18.0-14.9-27.0-22.8-18.2-31.5-33.8-17.0-7.1-6.7-15.2

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value145-982.0-281.0-176.0-299.01929.0-193.0-74.0-1237.0-248.0-195.0-104.0-364.0-207.0-151.0
Percentage of NetCashProvidedByUsedInInvestingActivities-18.8162.648.332.6-58.5-29.4-1.430.812.118.946.547.9-162.5110.057.558.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.5-38.6-13.8-10.9-19.19.00.3-9.2-3.6-48.7-8.2-14.1-7.2-17.1-7.8-11.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric18.30.00.00.0-41.40.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1572285-15.0296-1083.0-32.0687928423454023-214.0-564.0-192.034-141.0-102.0-36.0346-660.0-163.0-301.0-111.074436-123.0-151.0-423.0103-354.0287-543.0
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.289.9-0.718.4-69.2-1.52.13.813.892.4132.5-15.5-38.9-9.01.3-10.5-7.6-2.118.3-27.6-7.6-17.7-7.335.71.7-6.5-8.2-16.44.9-18.616.3-18.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-40.0191829184-286.0-205.019462-72.0-11.039858-286.0-274.011141
Percentage of NetCashProvidedByUsedInFinancingActivities-25.583.9-193.362.226.4640.6285.378.5-25.4-0.59.9-27.150.7142.7326.5-29.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.375.51.411.4-18.3-9.66.03.0-3.5-0.413.14.2-19.7-12.94.23.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-7.20.00.044.1-60.6-20.819.713.0-12.1-0.837.112.1-48.7-20.111.38.3

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-374.0940-100.0-80.079-315.0-344.0-208.0-84.01078-26.0-124.0-97.0139-97.0-174.0
Percentage of NetCashProvidedByUsedInFinancingActivities-238.241.1666.7-27.0-7.3984.4-505.9-263.3-29.646.0-0.657.917.2-72.4-285.3123.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-21.837.0-4.9-5.05.0-14.7-10.7-9.9-4.142.5-0.9-9.0-6.76.5-3.7-12.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric-47.30.00.00.010.90.00.00.00.00.00.00.00.00.00.00.0

Amortization Of Financing Costs

us-gaap:AmortizationOfFinancingCosts

us-gaap:AmortizationOfFinancingCosts


Amortization
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
Value8.07.05.08.08.07.07.08.07.07.01416126.06.06.06.06.07.06.07.06.06.07.07.07.07.07.07.07.07.07.08.08.09.08.07.08.08.07.08.07.06.07.07.07.0
Percentage of AmortizationOfFinancingCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmortizationOfFinancingCosts dei:LegalEntity

cnp:CercCorp


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value7.01.01.02.02.03.01.04.01.03.02.03.02.02.02.03.0
Percentage of AmortizationOfFinancingCosts87.514.320.025.025.042.914.350.014.342.914.318.816.733.333.350.0

cnp:HoustonElectric


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2.03.03.03.02.03.04.03.02.03.03.02.03.03.03.04.0
Percentage of AmortizationOfFinancingCosts25.042.960.037.525.042.957.137.528.642.921.412.525.050.050.066.7

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DeferredIncomeTaxExpenseBenefit


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-15.0660.048-100.0-377.06129-7.0-14.015455.0-17.0-955.09010.08563814.065-149.0-268.0-3.07.0186819.04.00.09920057911096464391951298087149-3.0-34.0
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxExpenseBenefit dei:LegalEntity

cnp:CercCorp


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-17.04172-7.03.023-19.06.0-1.02125-35.02714-293.0-46.0
Percentage of DeferredIncomeTaxExpenseBenefit113.362.10.0-14.6-3.0-6.1-31.120.714.3-150.0166.7-77.8540.0-82.430.7-51.1

cnp:HoustonElectric


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2.0-5.0-6.0-26.0-9.0-1.015-12.0-12.0-15.0-14.014-18.0-20.0-127.06.0
Percentage of DeferredIncomeTaxExpenseBenefit-13.3-7.60.0-54.29.00.324.6-41.4171.4107.1-93.331.1-360.0117.613.36.7

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value327307304306297282300334340313261326342314287269254226253324289260246268239217229293256235213248253240250301275224
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationDepletionAndAmortization dei:LegalEntity

cnp:CercCorp


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value8080787874747775767771777273776868
Percentage of DepreciationDepletionAndAmortization24.526.125.725.524.926.225.722.522.424.627.223.621.123.226.825.326.8

cnp:EnableMidstreamPartners


Depreciation
Period End2021-03-312020-03-31
Value106104
Percentage of DepreciationDepletionAndAmortization34.536.9

cnp:HoustonElectric


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value161141140151140129129168176175180242262233199193180
Percentage of DepreciationDepletionAndAmortization49.245.946.149.347.145.743.050.351.855.969.074.276.674.269.371.770.9

us-gaap:DepreciationDepletionAndAmortization us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

cnp:EnableMidstreamPartners


Depreciation
Period End2021-06-302020-09-302020-06-302019-09-302019-06-30
Value103105105108110
Percentage of DepreciationDepletionAndAmortization31.534.335.432.332.4

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-65.0-55.0253-30.0-29.0-192.0191-52.0-262.0-332.0482-16.0-37.0-209.027321-36.0-122.022319-27.0-82.0108-5.0-119.0-208.0234-63.0-302.0128303-43.0-75.0-33.018031-45.0-172.01345.0-52.0-168.0249-68.0-90.0-125.0
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity

cnp:CercCorp


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-66.0-10.01083.0-24.0-159.0153-16.0-187.0-255.0424-13.0-75.0-173.0291-24.0
Percentage of IncreaseDecreaseInAccountsPayable101.518.242.7-10.082.882.880.130.871.476.888.081.2202.782.8106.6-114.3

cnp:HoustonElectric


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value351435-16.011-2.010.01.00.02.05.00.010.0-16.0-46.048
Percentage of IncreaseDecreaseInAccountsPayable-53.8-25.513.853.3-37.91.05.2-1.9-0.0-0.61.0-0.0-27.07.7-16.8228.6

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value46-99.0-59.07288-110.0-33.095110-120.0-11.06287-139.0-45.03294-74.0-39.06849-112.05.07076-179.0-24.0116123-113.0-89.099131-119.0-30.08314-94.0-61.0116115-181.0-137.0107137-161.0
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInventories dei:LegalEntity

cnp:CercCorp


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value41-64.0-66.05562-114.0-35.07393-119.0-16.05777-135.0-27.031
Percentage of IncreaseDecreaseInInventories89.164.6111.976.470.5103.6106.176.884.599.2145.591.988.597.160.096.9

cnp:HoustonElectric


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value7.07.0137.01810.03.02.08.0-1.06.04.010.0-4.0-18.02.0
Percentage of IncreaseDecreaseInInventories15.2-7.1-22.09.720.5-9.1-9.12.17.30.8-54.56.511.52.940.06.2

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value605-1681.0556258519662552512303271457586609484393351360317257533481452503424439312510627403165383435
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax35.3-66.227.316.033.130.917.124.514.710.715.142.342.022.814.926.126.918.513.622.322.526.533.020.320.516.627.824.219.28.621.814.4

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value224-1787.08359206381-47.064201248-36.0104360386-34.034
Percentage of NetCashProvidedByUsedInOperatingActivities37.0106.314.922.939.757.6-8.512.566.391.5-7.917.759.179.8-8.79.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.1-70.34.13.713.217.8-1.53.19.89.8-1.27.524.818.2-1.32.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp40.10.00.014.143.638.7-4.813.433.718.1-3.421.761.328.3-3.56.9

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2074734727417510332335517466327345263180338288
Percentage of NetCashProvidedByUsedInOperatingActivities34.2-2.862.4106.233.715.658.569.357.424.471.658.943.237.286.082.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax12.11.817.117.011.24.810.017.08.52.610.824.918.28.512.821.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric26.20.00.00.024.20.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value251363200121105-1199.0157270195169120158-75.01651296169135192101179-2.0154-509.0-391.077131176143107185113151-100.014713410.0126147117973119148124123811141051148667
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.614.39.87.56.7-56.04.912.99.56.74.011.4-5.27.849.112.510.111.24.99.5-0.17.8-28.4-24.05.05.47.47.95.75.85.29.2-5.36.26.30.68.37.15.551.76.55.75.96.44.63.84.67.25.22.4

us-gaap:NetIncomeLoss dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value581515.0-4.0136753-7.028138339.0361305063854
Percentage of NetIncomeLoss23.141.62.5-3.312.4-5.633.8-2.614.481.727.55.7-48.078.839.022.540.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.45.90.2-0.20.83.11.6-0.31.45.41.10.62.56.119.22.84.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp10.40.00.0-1.02.86.85.4-1.54.710.13.11.96.19.551.77.79.3

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value10353571578733441851002740143101522101307518
Percentage of NetIncomeLoss41.014.628.5129.882.9-2.828.068.551.316.033.390.5-134.731.516.276.955.69.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.02.12.89.85.61.51.48.84.91.11.310.37.02.48.09.75.61.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric13.00.00.00.012.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

cnp:CercCorp, us-gaap:RetainedEarnings


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
Value581515.0-4.0136753-7.028138339.036130
Percentage of NetIncomeLoss23.141.62.5-3.312.4-5.633.8-2.614.481.727.55.7-48.078.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.45.90.2-0.20.83.11.6-0.31.45.41.10.62.56.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

cnp:HoustonElectric, us-gaap:RetainedEarnings


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
Value1035357157873344185100274014310152
Percentage of NetIncomeLoss41.014.628.5129.882.9-2.828.068.551.316.033.390.5-134.731.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.02.12.89.85.61.51.48.84.91.11.310.37.02.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value251363200121105-1199.0157270195169120158-75.0165
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.614.39.87.56.7-56.04.912.99.56.74.011.4-5.27.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-772.0-604.0-582.0-540.0511-654.0-646.0-626.0-610.0-6539.0-533.0-407.064-331.0-360.0-257.0-268.0-372.0-351.0-274.0-394.0-552.0-365.0-292.0-358.0-276.0-264.0-308.0-406.0-295.0-416.0-303.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-45.0-23.8-28.6-33.532.6-30.5-20.0-29.9-29.7-257.5-17.6-29.44.4-15.6-13.6-19.1-20.0-21.7-18.5-11.5-18.4-32.4-23.9-14.0-16.7-14.7-14.4-11.9-19.4-15.5-23.7-10.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-184.0-131.0-113.0-242.080-177.0-147.0-129.0-136.0-250.0-338.0-162.0-100.0-97.0-66.0-75.0
Percentage of NetCashProvidedByUsedInInvestingActivities23.821.719.444.815.727.122.820.622.33.863.439.8-156.229.318.329.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-10.7-5.2-5.6-15.05.1-8.3-4.6-6.2-6.6-9.8-11.1-11.7-6.9-4.6-2.5-5.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-33.00.00.0-58.016.9-18.0-14.9-27.0-22.8-18.2-31.5-33.8-17.0-7.1-6.7-15.2

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value145-982.0-281.0-176.0-299.01929.0-193.0-74.0-1237.0-248.0-195.0-104.0-364.0-207.0-151.0
Percentage of NetCashProvidedByUsedInInvestingActivities-18.8162.648.332.6-58.5-29.4-1.430.812.118.946.547.9-162.5110.057.558.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.5-38.6-13.8-10.9-19.19.00.3-9.2-3.6-48.7-8.2-14.1-7.2-17.1-7.8-11.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric18.30.00.00.0-41.40.00.00.00.00.00.00.00.00.00.00.0

Payments To Acquire Productive Assets

us-gaap:PaymentsToAcquireProductiveAssets

us-gaap:PaymentsToAcquireProductiveAssets


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value789594707611614664684653632537530424335362432345337312367365350332453419371341374373324301374326315271394294260264343327300333-2562.0326469258
Percentage of PaymentsToAcquireProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireProductiveAssets dei:LegalEntity

cnp:CercCorp


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value194133191248200176230224176146222181116114140150
Percentage of PaymentsToAcquireProductiveAssets24.622.427.040.632.626.533.634.327.827.241.942.734.631.532.443.5

cnp:HoustonElectric


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value421314308202262286281230256258244237211230272189
Percentage of PaymentsToAcquireProductiveAssets53.452.943.633.142.743.141.135.240.548.046.055.963.063.563.054.8

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1572285-15.0296-1083.0-32.0687928423454023-214.0-564.0-192.034-141.0-102.0-36.0346-660.0-163.0-301.0-111.074436-123.0-151.0-423.0103-354.0287-543.0
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.289.9-0.718.4-69.2-1.52.13.813.892.4132.5-15.5-38.9-9.01.3-10.5-7.6-2.118.3-27.6-7.6-17.7-7.335.71.7-6.5-8.2-16.44.9-18.616.3-18.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

cnp:CercCorp


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-40.0191829184-286.0-205.019462-72.0-11.039858-286.0-274.011141
Percentage of NetCashProvidedByUsedInFinancingActivities-25.583.9-193.362.226.4640.6285.378.5-25.4-0.59.9-27.150.7142.7326.5-29.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.375.51.411.4-18.3-9.66.03.0-3.5-0.413.14.2-19.7-12.94.23.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:CercCorp-7.20.00.044.1-60.6-20.819.713.0-12.1-0.837.112.1-48.7-20.111.38.3

cnp:HoustonElectric


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-374.0940-100.0-80.079-315.0-344.0-208.0-84.01078-26.0-124.0-97.0139-97.0-174.0
Percentage of NetCashProvidedByUsedInFinancingActivities-238.241.1666.7-27.0-7.3984.4-505.9-263.3-29.646.0-0.657.917.2-72.4-285.3123.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-21.837.0-4.9-5.05.0-14.7-10.7-9.9-4.142.5-0.9-9.0-6.76.5-3.7-12.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax cnp:HoustonElectric-47.30.00.00.010.90.00.00.00.00.00.00.00.00.00.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:ProceedsFromIssuanceOfLongTermDebt


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value169827955000.02990.00.01195100072114980.00.09970.07980.02980.03003000.00.00.00.00.00.00.00.06000.00.010500.00.08000.016950.00.00.05500.00.00.00.0
Percentage of ProceedsFromIssuanceOfLongTermDebt100.0100.0100.00.0100.00.00.0100.0100.0100.0100.00.00.0100.00.0100.00.0100.00.0100.0100.00.00.00.00.00.00.00.00.0100.00.00.0100.00.00.0100.00.0100.00.00.00.0100.00.00.00.00.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity

cnp:CercCorp


Proceeds
Period End2021-06-302021-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.016990.00.00.00.00.00.00.05990.0298
Percentage of ProceedsFromIssuanceOfLongTermDebt0.060.80.00.00.00.00.00.00.060.10.037.3

cnp:HoustonElectric


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.010960.00.02990.00.00.00.06960.00.00.03980.00.0
Percentage of ProceedsFromIssuanceOfLongTermDebt0.039.20.00.0100.00.00.00.00.096.50.00.00.039.90.00.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity, us-gaap:DebtInstrument

cnp:HoustonElectric, cnp:GeneralMortgageBondsDue2031And2051


Proceeds
Period End2021-03-31
Value1080
Percentage of ProceedsFromIssuanceOfLongTermDebt38.6

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-02-292012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value15723886642896963771488399411613865165614128644053631205881471311132611396010414223111826058361262956462755260.01430.07660.03357.0441
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.00.0100.0100.0100.0

us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity

cnp:HoustonElectric


Repayments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value372138712869636814867175661386516564128
Percentage of RepaymentsOfLongTermDebt23.735.610.7100.07.1100.088.3100.080.717.656.9100.0100.0100.010.4100.0

Payments Of Dividends

us-gaap:PaymentsOfDividends dei:LegalEntity

us-gaap:PaymentsOfDividends

cnp:CercCorp


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value0.08.040321.016832074751258626489140
Percentage of PaymentsOfDividends0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cnp:HoustonElectric


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value94522038527660162486603132934510.0
Percentage of PaymentsOfDividends0.0650.050.01203.127600.0375.019.3120.0116.280.024.837.235.250.67.1

Payments Of Dividends Common Stock

us-gaap:PaymentsOfDividendsCommonStock

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