NWN


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

Table of contents



us-gaap:CommonStockValue
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesOutstanding
us-gaap:StatementEquityComponents

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:GrossProfit

us-gaap:IncomeLossFromContinuingOperations
us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
dei:LegalEntity

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:IncomeTaxesPaidNet
dei:LegalEntity

us-gaap:InterestIncomeExpenseNonoperatingNet
dei:LegalEntity

us-gaap:InterestPaidNet
dei:LegalEntity

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

us-gaap:OperatingCostsAndExpenses

us-gaap:OperatingExpenses
dei:LegalEntity

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

us-gaap:OtherNonoperatingIncomeExpense
dei:LegalEntity
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:RegulatedOperatingRevenue
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService
dei:LegalEntity, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService

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

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

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

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

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

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity

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

us-gaap:AssetsNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:PropertyPlantAndEquipmentGross
dei:LegalEntity
us-gaap:StatementBusinessSegments

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
dei:LegalEntity
us-gaap:StatementBusinessSegments

us-gaap:PropertyPlantAndEquipmentNet
dei:LegalEntity
us-gaap:StatementBusinessSegments

us-gaap:Goodwill
us-gaap:BusinessAcquisition

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

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

us-gaap:AccountsPayableCurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:AccruedIncomeTaxesCurrent
dei:LegalEntity

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

us-gaap:LongTermDebtCurrent
dei:LegalEntity

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

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

us-gaap:LongTermDebt
dei:LegalEntity

us-gaap:LongTermDebtNoncurrent
dei:LegalEntity

us-gaap:DeferredIncomeTaxLiabilitiesNet
dei:LegalEntity

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity

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

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

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

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

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive
dei:LegalEntity

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

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

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue
dei:LegalEntity
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:TypeOfArrangement

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

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

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

us-gaap:CommonStockValue
dei:LegalEntity
us-gaap:ConsolidatedEntities

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

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

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:DepreciationDepletionAndAmortization
dei:LegalEntity

us-gaap:IncreaseDecreaseInAccountsPayable
dei:LegalEntity

us-gaap:IncreaseDecreaseInInventories
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

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

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

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity

us-gaap:PaymentsOfDividendsCommonStock
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:DebtInstrumentInterestRateStatedPercentage
us-gaap:ConsolidationItems, us-gaap:DebtInstrument, us-gaap:StatementBusinessSegments
us-gaap:DebtInstrument

us-gaap:EffectiveIncomeTaxRateContinuingOperations
dei:LegalEntity
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
us-gaap:AwardType, us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

us-gaap:DeferredTaxLiabilities
dei:LegalEntity

us-gaap:DeferredTaxAssetsNet
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfShortTermDebt
dei:LegalEntity
us-gaap:MajorCustomers
nwn:AdditionalRatePerTherm
us-gaap:RetirementPlanType
nwn:AmortizationofRegulatoryBalancingAccount

nwn:AnnualInsuranceProceedstoApplyAgainstRemediationCosts

nwn:AnnualTariffRiderCollection

nwn:ChangeInDecouplingRegulatoryDeferral
dei:LegalEntity
us-gaap:EnvironmentalRemediationSite
nwn:CostIncurredStudiesandDesignCosts
us-gaap:DebtInstrument
nwn:DebtInstrumentCovenantConsolidatedIndebtednesstoCapitalizationRatio
us-gaap:RetirementPlanType
nwn:DefinedBenefitPlanAmountAllocatedToConstruction
us-gaap:RetirementPlanType
nwn:DefinedBenefitPlanNetAmountChargedToExpense
us-gaap:RetirementPlanType
nwn:DefinedBenefitPlanNetPeriodicBenefitCostChargedToExpense

nwn:ExciseTaxes
dei:LegalEntity

nwn:OtherTaxExpenseBenefitdifferencestobeflowedthroughbyregulatorycommissions
dei:LegalEntity

nwn:RepaymentsOfCommercialPaperMaturitiesGreaterThan90Days
dei:LegalEntity
us-gaap:StatementEquityComponents
nwn:StockIssuedDuringPeriodValueEquityBasedPlanNetofSharesWithheldforTaxes

nwn:TotalAnnualRemediationExpenseandInterest
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
nwn:TotalExpensesDiscontinuedOperations
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
us-gaap:EquitySecuritiesByIndustry

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries
us-gaap:EquitySecuritiesByIndustry

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs
us-gaap:EquitySecuritiesByIndustry

us-gaap:AmortizationOfRegulatoryAsset
dei:LegalEntity
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationConsiderationTransferred1
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual
us-gaap:BusinessAcquisition
us-gaap:BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
dei:LegalEntity

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations

us-gaap:CommonStockDividendsPerShareCashPaid

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

us-gaap:DefinedContributionPlanCostRecognized

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

us-gaap:DerivativeGainOnDerivative
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeLossOnDerivative
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherExpense
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:DividendsCommonStockCash
us-gaap:StatementEquityComponents

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
us-gaap:Range, us-gaap:EnvironmentalRemediationSite
us-gaap:EnvironmentalExitCostsAnticipatedCost

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

us-gaap:FinanceLeasePrincipalPayments
dei:LegalEntity
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk
us-gaap:GainLossOnDerivativeInstrumentsNetPretax
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk, us-gaap:RegulatoryAsset

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate
dei:LegalEntity

us-gaap:IncomeTaxReconciliationOtherAdjustments
dei:LegalEntity

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes
dei:LegalEntity

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables
dei:LegalEntity

us-gaap:IncreaseDecreaseInAccruedTaxesPayable
dei:LegalEntity

us-gaap:IncreaseDecreaseInDeferredGasCost
dei:LegalEntity

us-gaap:IncreaseDecreaseInInterestPayableNet
dei:LegalEntity

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
dei:LegalEntity

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:LeaseIncome

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

us-gaap:OperatingLeaseLeaseIncome
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService

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

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax
dei:LegalEntity

us-gaap:OtherCostAndExpenseOperating
dei:LegalEntity

us-gaap:OtherIncreaseDecreaseInEnvironmentalLiabilities
dei:LegalEntity

us-gaap:OtherNoncashIncomeExpense
dei:LegalEntity

us-gaap:PaymentsForCapitalImprovements
dei:LegalEntity

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired

us-gaap:PaymentsToAcquireOilAndGasPropertyAndEquipment
dei:LegalEntity

us-gaap:PensionAndOtherPostretirementBenefitContributions

us-gaap:PensionContributions
dei:LegalEntity

us-gaap:PensionExpense
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:ProceedsFromIssuanceOfDebt

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfLinesOfCredit
dei:LegalEntity

us-gaap:ProceedsFromSaleOfEquityMethodInvestments
us-gaap:BalanceSheetLocation, us-gaap:SubsequentEventType
us-gaap:StatementScenario, us-gaap:BalanceSheetLocation

us-gaap:ProceedsFromSaleOfLandHeldForUse
dei:LegalEntity

us-gaap:ProceedsFromShortTermDebt
dei:LegalEntity

us-gaap:ProceedsFromStockOptionsExercised
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:RegulatedOperatingRevenueOther
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:SubsequentEventType
us-gaap:RepaymentsOfDebt

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability
dei:LegalEntity

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability
dei:LegalEntity

us-gaap:SalesTypeLeaseLeaseIncome

us-gaap:ShortTermLeaseCost
dei:LegalEntity
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueEmployeeStockPurchasePlan
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation

us-gaap:TaxesExcludingIncomeAndExciseTaxes
dei:LegalEntity

us-gaap:UnrealizedGainLossOnDerivatives

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased
dei:LegalEntity
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
dei:LegalEntity
us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:UtilitiesOperatingExpenseTaxes

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity
nwn:CumulativeGrossInvestment

nwn:DeferredTaxAssetsLeaseLiabilities
dei:LegalEntity

nwn:DeferredTaxLiabilitiesLeaseRightOfUseAssets
dei:LegalEntity

nwn:DeferredTaxesRelatedToGasReserves
dei:LegalEntity
us-gaap:RetirementPlanType
nwn:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets

nwn:DefinedBenefitPlanHealthCareCostTrendRateAssumedThereafter
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
nwn:DiscontinuedOperationOperatingLeaseLiabilities
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
nwn:DiscontinuedOperationOperatingleaseRightofUseAsset
dei:LegalEntity, us-gaap:Range
nwn:EPARecordOfDecisionCleanUpCostsPortlandHarbor
dei:LegalEntity, us-gaap:EnvironmentalRemediationSite
nwn:EnvironmentalProjectLiability
dei:LegalEntity, nwn:EnvironmentalActivity, us-gaap:RegulatoryAsset
nwn:EnvironmentalRegulatoryAccruedSiteLiabilities
dei:LegalEntity, us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:RegulatoryAsset
nwn:EnvironmentalRegulatoryDeferredCostandInterest
dei:LegalEntity, us-gaap:RegulatoryAsset
nwn:EnvironmentalRegulatoryInsuranceProceedsandInterest
dei:LegalEntity
nwn:EnvironmentalSettlementInsuranceProceedsReceivedToDate

nwn:GasReservesAmortization
dei:LegalEntity
dei:LegalEntity
nwn:GasReservesInvestment

nwn:GasReservesNoncurrentGross
dei:LegalEntity
dei:LegalEntity
nwn:InsuranceProceedsAppliedToPrudentlyIncurredRemediationCosts
dei:LegalEntity
nwn:InvestmentinAdditionalWellsGasReserves
us-gaap:ConsolidatedEntities
nwn:InvestmentsinSubsidiaries

nwn:LeasePaymentstobeReceived
dei:LegalEntity

nwn:LeasePaymentstobeReceivedFiveYears
dei:LegalEntity

nwn:LeasePaymentstobeReceivedFourYears
dei:LegalEntity

nwn:LeasePaymentstobeReceivedNexttwelvemonths

nwn:LeasePaymentstobeReceivedRemainderofFiscalYear
dei:LegalEntity

nwn:LeasePaymentstobeReceivedThereafter
dei:LegalEntity

nwn:LeasePaymentstobeReceivedThreeYears
dei:LegalEntity

nwn:LeasePaymentstobeReceivedTwoYears
dei:LegalEntity
dei:LegalEntity, us-gaap:EnvironmentalRemediationSite
nwn:LiabilityForStudiesAndDesignCosts
dei:LegalEntity
nwn:LongTermDebtCurrentMaturitiesGross
dei:LegalEntity
nwn:LongtermDebtExcludingCurrentMaturitiesGross

nwn:NetGasReservesInvestment
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementBusinessSegments
nwn:PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccount
dei:LegalEntity, us-gaap:StatementBusinessSegments
nwn:PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccountWhenInRates
dei:LegalEntity, us-gaap:StatementBusinessSegments
nwn:PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreInUtilityRates
dei:LegalEntity, us-gaap:StatementBusinessSegments
nwn:PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreNotInUtilityRates
us-gaap:Ownership
nwn:PercentOwnershipInJointProject
dei:LegalEntity, us-gaap:RetirementPlanType
nwn:PlanAssetReceivableOrPayableAccruedInterestAndDividendIncome
dei:LegalEntity, us-gaap:RetirementPlanType
nwn:PlanAssetReceivableOrPayableDueFromBrokerSecuritiesPurchased
us-gaap:StatementBusinessSegments
nwn:PropertyPlantEquipmentnoncash
us-gaap:RegulatoryAsset
nwn:RegulatoryAssetsActuarialGainLoss
dei:LegalEntity, us-gaap:RegulatoryAsset
nwn:RegulatoryAssetsEnvironmentalRegulatoryAccruedSiteLiabilities
nwn:EnvironmentalActivity, us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:RegulatoryAsset
nwn:RegulatoryAssetsEnvironmentalRegulatoryDeferredCostandInterest
us-gaap:RegulatoryAsset
nwn:RegulatoryAssetsPriorServiceCost

nwn:RemediationNonrecoveryPercentage
us-gaap:StatementGeographical
nwn:RemediationRecoveryPercentage
dei:LegalEntity
nwn:ReservedSharesDividendReinvestment
us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName
nwn:ShareBasedCompensationAwardTargetShare
us-gaap:AwardType, us-gaap:PlanName
us-gaap:Range, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName
us-gaap:Range, us-gaap:AwardType, us-gaap:PlanName
us-gaap:StatementScenario, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName
us-gaap:PlanName
nwn:SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofSharesAvailableforGrantAnyAwardType
dei:LegalEntity, nwn:GasYear, us-gaap:DerivativeInstrumentRisk
nwn:TargetHedgeAchieved
dei:LegalEntity
nwn:TotalCumulativeGasReservesInvestment

nwn:TotalGasReserves
dei:LegalEntity
us-gaap:MajorCustomers
nwn:TotalGasReservesInvestment
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
nwn:TotalPensionAssetInvestmentsNetOfReceivablesAndPayables
dei:LegalEntity, us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
nwn:TotalPensionPlanAssetReceivables
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
nwn:UnrecordedUnconditionalPurchaseObligationAmountRepresentingInterest
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
nwn:UnrecordedUnconditionalPurchaseObligationTotalAtPresentValue
dei:LegalEntity, us-gaap:CreditRatingMoodys
nwn:WithAdequateAssuranceCalls
dei:LegalEntity, us-gaap:CreditRatingMoodys
nwn:WithoutAdequateAssuranceCalls

us-gaap:AccountsReceivableGrossCurrent
dei:LegalEntity

us-gaap:AccruedEnvironmentalLossContingenciesCurrent
dei:LegalEntity
dei:LegalEntity, nwn:EnvironmentalActivity
us-gaap:EnvironmentalRemediationSite

us-gaap:AccruedEnvironmentalLossContingenciesNoncurrent
dei:LegalEntity
dei:LegalEntity, nwn:EnvironmentalActivity
us-gaap:EnvironmentalRemediationSite

us-gaap:AllowanceForDoubtfulAccountsReceivable
us-gaap:EquitySecuritiesByIndustry

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperation
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent
us-gaap:BalanceSheetLocation
us-gaap:BankOverdrafts
us-gaap:BusinessAcquisition
us-gaap:BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount

us-gaap:CapitalLeasesLessorBalanceSheetNetInvestmentInDirectFinancingAndSalesTypeLeasesNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:PlanName
us-gaap:CommonStockCapitalSharesReservedForFutureIssuance

us-gaap:DebtInstrumentCarryingAmount
dei:LegalEntity

us-gaap:DebtInstrumentFairValue
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:DebtWeightedAverageInterestRate
us-gaap:DebtInstrument

us-gaap:DeferredCreditsAndOtherLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:DeferredGasCost
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredIncomeTaxLiabilities
dei:LegalEntity

us-gaap:DeferredTaxAssetsGoodwillAndIntangibleAssets

us-gaap:DeferredTaxAssetsOther
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryLiability
us-gaap:DeferredTaxAssetsRegulatoryAssetsAndLiabilities
us-gaap:RegulatoryLiability

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsOther
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesLeasingArrangements
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryLiability
us-gaap:DeferredTaxLiabilitiesRegulatoryAssets
us-gaap:RegulatoryLiability
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
us-gaap:Range, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear
dei:LegalEntity, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFairValueOfPlanAssets
dei:LegalEntity, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
dei:LegalEntity, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
dei:LegalEntity, us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1

us-gaap:DerivativeAssetsCurrent
dei:LegalEntity

us-gaap:DerivativeAssetsNoncurrent
dei:LegalEntity
dei:LegalEntity
us-gaap:DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
dei:LegalEntity
us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral

us-gaap:DerivativeFairValueOfDerivativeNet

us-gaap:DerivativeLiabilitiesCurrent
dei:LegalEntity

us-gaap:DerivativeLiabilitiesNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk, us-gaap:UnderlyingAssetClass
us-gaap:DerivativeNonmonetaryNotionalAmount
dei:LegalEntity, us-gaap:UnderlyingAssetClass
us-gaap:DerivativeNotionalAmount
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentAssets
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherNoncurrentLiabilities
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent
dei:LegalEntity
us-gaap:DueFromAffiliateCurrent
us-gaap:ConsolidatedEntities
dei:LegalEntity
us-gaap:DueToAffiliateCurrent
us-gaap:ConsolidatedEntities
us-gaap:AwardType, us-gaap:PlanName
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
dei:LegalEntity
us-gaap:EnergyRelatedInventoryNaturalGasInStorage
us-gaap:EnvironmentalRemediationSite
us-gaap:EnvironmentalExitCostsCostsAccruedToDate

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FinanceLeaseRightOfUseAsset

us-gaap:IncomeTaxesReceivable
us-gaap:ConsolidatedEntities

us-gaap:InterestPayableCurrent
dei:LegalEntity

us-gaap:InventoryGasInStorageUndergroundNoncurrent
dei:LegalEntity

us-gaap:InventoryRawMaterialsAndSuppliesNetOfReserves

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

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

us-gaap:LessorOperatingLeasePaymentsToBeReceived
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFiveYears

us-gaap:LessorOperatingLeasePaymentsToBeReceivedFourYears
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThereafter
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedThreeYears
dei:LegalEntity

us-gaap:LessorOperatingLeasePaymentsToBeReceivedTwoYears
dei:LegalEntity
us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:LifeInsuranceCorporateOrBankOwnedAmount
us-gaap:ConsolidatedEntities
us-gaap:CreditFacility
us-gaap:LineOfCredit
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
dei:LegalEntity, us-gaap:RetirementPlanName
us-gaap:MultiemployerPlansWithdrawalObligation

us-gaap:NetInvestmentInLeaseNoncurrent
dei:LegalEntity

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

us-gaap:OtherInvestments

us-gaap:OtherLongTermInvestments
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:PublicUtilitiesInventory
dei:LegalEntity
us-gaap:StatementBusinessSegments
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress

us-gaap:RatioOfIndebtednessToNetCapital1
dei:LegalEntity
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:ReceivableWithImputedInterestDiscount
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:ReceivableWithImputedInterestNetAmount
us-gaap:TypeOfArrangement
dei:LegalEntity, nwn:IncomeTaxAssetType, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAssets
dei:LegalEntity, us-gaap:FairValueByAssetClass, us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset

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

us-gaap:RegulatoryAssetsNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:RegulatoryAsset
us-gaap:BalanceSheetLocation, us-gaap:RegulatoryAsset
us-gaap:RegulatoryAsset
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:RegulatoryLiability
us-gaap:RegulatoryLiabilities

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

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

us-gaap:ResidualValueOfLeasedAsset
dei:LegalEntity, us-gaap:BalanceSheetLocation
us-gaap:RestrictedCashAndCashEquivalents
dei:LegalEntity
us-gaap:RestrictedCashCurrent
us-gaap:BalanceSheetLocation

us-gaap:RevenueRemainingPerformanceObligation
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceived
us-gaap:TypeOfArrangement
us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFiveYears
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedFourYears
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedNextTwelveMonths
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedRemainderOfFiscalYear
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThereafter
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedThreeYears
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:TypeOfArrangement
us-gaap:SalesTypeAndDirectFinancingLeasesLeaseReceivablePaymentsToBeReceivedTwoYears
us-gaap:TypeOfArrangement
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:SecuredDebt
us-gaap:AwardType, us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
us-gaap:AwardType, us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue

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

us-gaap:ShortTermDebtWeightedAverageInterestRate
dei:LegalEntity
us-gaap:ShareRepurchaseProgram
us-gaap:StockRepurchaseProgramAuthorizedAmount1
us-gaap:ShareRepurchaseProgram
us-gaap:StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased

us-gaap:UnamortizedDebtIssuanceExpense
dei:LegalEntity

us-gaap:UnbilledReceivablesCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears

Plots across concepts


IncomeStatement
Income Loss From Continuing Operations 
Before Income Taxes Extraordinary Items Noncontrolling Interest
Expenses
Other Nonoperating Income Expense
Balance Sheet
Cash And Cash Equivalents At Carrying Value
Assets
Cash And Cash Equivalents At Carrying Value
Current Assets
Cash And Cash Equivalents At Carrying Value
NonCurrent Assets
Other Assets Noncurrent
PropertyPlantAndEquipmentNet
Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
Liabilities
Operating Lease Liability
Current Liabilities
Operating Lease Liability Current
Noncurrent Liabilities
Operating Lease Liability Noncurrent
Stockholders Equity
Accumulated Other Comprehensive Income Loss Net Of Tax
Per Share
Earnings Per Share Diluted
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 Diluted Shares Outstanding
OperatingLeaseLiability
Operating Lease Liability Current
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Payments Remainder Of Fiscal Year

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:CommonStockValue ██████▇▇▇▂▁▁▁▁569.785568.066565.112563.852562.766561.264558.282556.623555.052459.932457.64455.499452.195450.408
us-gaap:CommonStockSharesIssued █████▇▇▇▇▂▁▁▁▁30.67230.65530.58930.56530.54630.52830.47230.43530.42228.96228.8828.84428.828.781
us-gaap:CommonStockSharesOutstanding █████▇▇▇▇▂▁▁▁▁30.67230.65530.58930.56530.54630.52830.47230.43530.42228.96228.8828.84428.828.781
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁30.66430.633NA30.55530.53730.53530.52130.42929.39428.9728.9428.81528.79128.803
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁30.66430.614NA30.55530.53730.49130.44830.42929.33728.90628.85128.81528.79128.753
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount █▁0.0480.012NA0.0470.0410.003NA0.0690.0010.005NA0.0730.0530.016
us-gaap:EarningsPerShareBasic ▃█▇▁▂▇▆▁▃▇▆▂▃▇-0.021.941.6999999999999997-0.59-0.161.561.21-0.630.041.491.24-0.41-0.031.44
us-gaap:EarningsPerShareDiluted ▃█▇▁▂▇▆▁▃▇▆▂▃▇-0.021.941.6999999999999997-0.59-0.161.561.2-0.630.041.491.24-0.41-0.031.44
us-gaap:IncomeLossFromContinuingOperationsPerBasicShare ▃█▇▁▂▇▆▁▃▇▆▂▃▇-2e-081.94e-061.4999999999999998e-06-6.1e-07-1.7000000000000001e-071.5800000000000001e-061.26e-06-6.1e-077e-081.5e-061.2700000000000001e-06-3.9e-07-1e-081.46e-06
us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare ▃█▇▁▂▇▆▁▃▇▆▂▃▇-2e-081.94e-061.4999999999999998e-06-6.1e-07-1.7000000000000001e-071.5800000000000001e-061.26e-06-6.1e-077e-081.5e-061.2700000000000001e-06-3.9e-07-1e-081.46e-06
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
 EBT Margin dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▆▁▂▇▆▁▂▇▅▁▂▆144.579312.35256.69588.367131.157282.529245.26487.592122.242284.846226.14691.227124.563263.635
 Gross Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NaturalGasDistribution▃█▆▁▂▇▆▁▂▇▅▁▂▇139.614301.338251.83283.761126.992278.487240.4483.063117.984279.041219.12385.077118.515257.933
 Operating Margin dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▆▁▂▇▆▁▂▇▅▁▂▆144.579312.35256.69588.367131.157282.529245.26487.592122.242284.846226.14691.227124.563263.635
 Operating Margin us-gaap:ConsolidatedEntities srt:ParentCompany▃█▆▁▂▇▆▁▂▇▅▁▂▆148.917315.946260.27393.284134.971285.151247.26490.317123.443285.348226.70291.239124.567263.635
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:OtherNorthwestNatural▂█▂▂▁▁▂▁▁▃▄▃▃▃4.96511.0124.8634.6064.1654.0424.8244.5294.2585.8057.0236.156.0485.702
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NaturalGasDistribution▃█▆▁▂▇▆▁▂▇▅▁▂▇139.614301.338251.83283.761126.992278.487240.4483.063117.984279.041219.12385.077118.515257.933
 Operating Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NorthwestNaturalGasCompany▃█▆▁▂▇▆▁▂▇▅▁▂▆144.579312.35256.69588.367131.157282.529245.26487.592122.242284.846226.14691.227124.563263.635
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
 TTM Greenblatt ROC _ _▃█▇▁▂▇▆▁▃▇▆▁▂12.62494.70674.551-11.5888.94276.44660.965-9.63416.09876.04562.253-6.1118.269NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:ComprehensiveIncomeNetOfTax ▃█▇▁▂▇▆▁▃▇▆▂▃▆-0.50359.73849.372-17.726-4.69247.65834.217-19.1871.2143.31636.613-11.64-0.84541.691
 us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▇▁▂▇▆▁▃▇▆▂▃▆0.8160.33243.641-20.034-4.55249.33937.09-17.4743.16944.0138.37-11.64-0.84541.691
 us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity,us-gaap:StatementEquityComponents nwn:NorthwestNaturalGasCompany,us-gaap:AccumulatedOtherComprehensiveIncome▇▇▁▇▇▇▁▇▇▇█▇▇▇0.2210.221-2.6750.1860.160.16-2.5230.1140.1150.1150.7890.1540.1530.154
 us-gaap:ComprehensiveIncomeNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedOtherComprehensiveIncome▇▇▁▇▇▇▁▇▇▇█▇▇▇0.2210.221-2.6750.1860.160.16-2.5230.1140.1150.1150.7890.1540.1530.154
 us-gaap:GrossProfit us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NaturalGasDistribution▃█▇▁▂▇▆▁▃▇▅▁▂▆91.206172.64148.77355.54279.651154.144133.19255.90380.981152.655126.29454.9469.746132.716
us-gaap:IncomeLossFromContinuingOperations ▃█▇▁▂▇▆▁▃▇▆▂▃▆-0.72459.51745.806-18.677-5.13248.27638.348-18.5062.05143.41836.783-11.144-0.33942.011
 us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidatedEntities srt:ParentCompany▃█▇▁▂▇▆▁▃▇▆▂▃▆-0.72459.51745.806-18.677-5.13248.27638.348-18.5062.05143.41836.783-11.144-0.33942.011
 us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:OtherNorthwestHoldings▁▃▃█▃▂▁▂▂▃▂▅▄▄-1.313-0.594-0.511.543-0.42-0.903-1.265-0.918-1.003-0.477-0.7980.131-0.068-0.003
 us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:OtherNorthwestNatural▃█▃▃▂▂▂▃▂▄▇▁▄▃1.976.1862.2371.91.6351.2361.6331.9821.8422.6895.020.7082.6992.131
 us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NaturalGasDistribution▃█▇▁▂▇▇▁▃▇▆▂▃▇-1.38153.92544.079-22.12-6.34747.94337.98-19.571.21241.20632.561-11.983-2.9739.883
 us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NorthwestNaturalGasCompany▃█▇▁▂▇▆▁▃▇▆▂▃▆0.58960.11146.316-20.22-4.71249.17939.613-17.5883.05443.89537.581-11.275-0.27142.014
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▃█▇▁▂▇▆▁▃▆▆▂▃▆-1.00180.03859.796-24.04-6.80462.40346.033-22.8492.67652.09349.783-15.429-0.49557.643
 us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▇▁▂▇▆▁▃▆▆▂▃▆0.87780.66360.469-26.277-6.13163.59747.858-21.6014.03952.74350.866-15.608-0.39957.649
us-gaap:IncomeTaxExpenseBenefit ▂█▆▁▂▆▅▁▃▅▆▁▂▇-0.27720.52113.99-5.363-1.67214.1277.685-4.3430.6258.67513.0-4.285-0.15615.632
 us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▆▁▂▆▅▂▃▅▆▁▃▇0.28820.55214.153-6.057-1.41914.4188.245-4.0130.9858.84813.285-4.333-0.12815.635
us-gaap:IncomeTaxesPaidNet ▇▄▆█▄▄▆▄▁▄▆█▅█6.6050.84.38.80.8-0.2566.0-0.001-6.005-0.095.3238.73.5479.8
us-gaap:InterestIncomeExpenseNonoperatingNet ▄▄▅▇▁▅▄▄▅▅▆██▇-11.028-11.126-10.713-9.165-12.706-10.468-10.878-10.948-10.654-10.205-10.008-9.006-8.771-9.274
 us-gaap:InterestIncomeExpenseNonoperatingNet dei:LegalEntity nwn:NorthwestNaturalGasCompany▄▃▄█▁▆▄▄▄▅▅▇█▇-10.696-10.79-10.348-8.806-11.851-9.861-10.36-10.459-10.387-10.133-9.94-9.007-8.771-9.274
us-gaap:InterestPaidNet ▆▃▆▁█▂▇▂▅▂▆12.9958.97612.8226.67314.7888.36813.4958.01111.7497.97612.503NANANA
us-gaap:NetIncomeLoss ▃█▇▁▂▇▆▁▃▇▆▂▃▆-0.72459.51752.047-17.912-4.85247.49836.74-19.3011.09543.20135.824-11.794-0.99841.537
 us-gaap:NetIncomeLoss dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▇▁▂▇▆▁▃▇▆▂▃▆0.58960.11146.316-20.22-4.71249.17939.613-17.5883.05443.89537.581-11.794-0.99841.537
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:StatementEquityComponents nwn:NorthwestNaturalGasCompany,us-gaap:RetainedEarnings▁█0.58960.111NA-20.22-4.71249.179NA-17.5883.05443.895NA-11.794-0.99841.537
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▁█-0.72459.517NA-17.912-4.85247.498NA-19.3011.09543.201NA-11.794-0.99841.537
us-gaap:OperatingCostsAndExpenses ▇▇▇▇▇▇▇▇▇▇▁█▇▇50.04752.19145.87341.35243.98348.92146.33740.88639.48651.482-252.83497.3538.02839.523
us-gaap:OperatingExpenses ▃█▆▁▃▇▆▁▂▇▅▁▂▇136.293221.24185.722104.872126.029208.705186.29999.951107.345209.303164.44997.35116.298195.884
us-gaap:OperatingIncomeLoss ▃█▇▁▂▇▆▁▃▇▆▁▂▆12.62494.70674.551-11.5888.94276.44660.965-9.63416.09876.04562.253-6.1118.26967.751
us-gaap:OtherNonoperatingIncomeExpense ▇▆▆▆▆▆▆▇▇▁▇███-2.597-3.542-4.042-3.287-3.04-3.575-4.054-2.267-2.768-13.747-2.462-0.3120.007-0.834
 us-gaap:OtherNonoperatingIncomeExpense dei:LegalEntity nwn:NorthwestNaturalGasCompany▇▆▆▆▆▆▆▇▇▁▇███-2.566-3.665-4.372-4.002-3.179-3.563-4.063-2.323-2.814-13.768-2.431-0.32-0.033-0.815
 us-gaap:RegulatedOperatingRevenue us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NaturalGasDistribution▃█▆▁▂▇▆▁▂▇▆▁▂134.849296.553246.96179.357122.071273.561235.78177.916115.792278.983219.0884.965118.435NA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService nwn:NorthwestNaturalGasCompany,us-gaap:CorporateNonSegment,nwn:ApplianceCenterRevenue,nwn:OtherNorthwestNatural,us-gaap:TransferredAtPointInTime▄▆█▃▁▆█▂▃▆█▂▃▆1.3431.5891.8381.1850.8061.5561.9090.9881.0581.5161.8581.0211.1711.546
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService nwn:NorthwestNaturalGasCompany,us-gaap:CorporateNonSegment,nwn:AssetManagementRevenueNetofRegulatorySharing,nwn:OtherNorthwestNatural,us-gaap:TransferredOverTime▂█▁▂▂▁▁▂▁▂▂▄▃▂0.8176.9280.5330.9390.910.150.5311.2080.461.5061.5742.7142.141.579
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService nwn:NorthwestNaturalGasCompany,us-gaap:CorporateNonSegment,nwn:GasStorageRevenueNetofRegulatorySharing,nwn:OtherNorthwestNatural,us-gaap:TransferredOverTime▄▂▂▂▂▁▁▁▃▄█▁▃▂2.8052.4952.4922.4822.4492.3362.3842.3332.742.7833.5912.4152.7372.577
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments nwn:NorthwestNaturalGasCompany,us-gaap:CorporateNonSegment,nwn:OtherNorthwestNatural▂█▂▂▁▁▂▁▁▃▄▃▃▃4.96511.0124.8634.6064.1654.0424.8244.5294.2585.8057.0236.156.0485.702
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments,us-gaap:TimingOfTransferOfGoodOrService us-gaap:CorporateNonSegment,nwn:Otherrevenue,nwn:OtherNorthwestHoldings,us-gaap:TransferredOverTime▇▆▆█▆▅▄▅▃▂▂▁▁▁4.3383.5963.5784.9173.8142.6222.02.7251.2010.5020.5560.0120.0040.0
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:OtherNorthwestHoldings▇▆▆█▆▅▄▅▃▂▂▁▁▁4.3383.5963.5784.9173.8142.6222.02.7251.2010.5020.5560.0120.0040.0
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax ▂█▆▁▂▇▆▁▂█▅▁▂▇133.441311.106250.08588.283124.993281.005247.93587.981117.578302.493222.92988.52120.778263.931
us-gaap:Revenues ▃█▆▁▂▇▆▁▂▇▅▁▂▆148.917315.946260.27393.284134.971285.151247.27490.317123.443285.348226.70291.239124.567263.635
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:Assets ▆▆▆▅▆█▄▃▃▂▃▂▁▁3783.53758.6253756.3793618.0973641.3474001.5273428.4543251.6183238.1313191.1173242.6623081.4072986.763029.339
us-gaap:LiabilitiesAndStockholdersEquity ▆▆▆▅▆█▄▃▃▂▃▂▁▁3783.53758.6253756.3793618.0973641.3474001.5273428.4543251.6183238.1313191.1173242.6623081.4072986.763029.339
us-gaap:StockholdersEquity ██▆▅▆▇▆▅▆▃▂▁▂▂922.826936.324888.733852.775884.001901.741865.999844.669876.746794.227762.634737.581759.526772.205
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:AssetsCurrent ▂▃▃▂▃█▂▁▂▂▂▁▁▂273.841302.792323.245242.848316.436720.267293.692202.727239.058272.109295.921218.159180.844241.694
us-gaap:CashAndCashEquivalentsAtCarryingValue ▁▁▁▁▃█▁▁▂▁▁▁▁▁20.08417.90730.16835.926137.057471.0799.64810.52260.88512.81712.63329.9658.75511.215
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▃▁█28.3125.51235.454NA142.548475.86412.636NANANANANANANA
us-gaap:OtherAssetsCurrent ▃▅█▄▃▄▇▂▂▃▅▃▁▂22.42730.65644.74125.53420.31826.4638.00418.61718.29620.29328.47220.37611.67216.877
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:AssetsNoncurrent █▇▇▇▆▆▄▄▃▂▃▂▁▁3509.6593455.8333433.1343375.2493324.9113281.263134.7623048.8912999.0732919.0082946.7412863.2482805.9162787.645
us-gaap:PropertyPlantAndEquipmentGross █▇▇▆▅▅▄▃▂▃▃▂▂▁3849.7923788.2833734.0393680.8723608.9023551.0653476.7463416.7183355.8113439.463414.493370.3883298.8563251.075
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment ██▇▇▆▆▅▄▄▃▂▂▂▁1093.8631091.9031079.2691073.6231062.2991050.851037.8471027.331016.1851005.117993.118996.994984.998972.773
us-gaap:PropertyPlantAndEquipmentNet █▇▇▆▅▄▃▃▂▃▃▂▂▁2755.9292696.382654.772607.2492546.6032500.2152438.8992389.3882339.6262434.3432421.3722373.3942313.8582278.302
us-gaap:Goodwill ██████▆▆▆▂▂▂▁▁69.31369.3369.22570.29270.18369.2249.92949.33349.3938.9548.9546.5630.00.0
us-gaap:OperatingLeaseRightOfUseAsset ██████▁▁▁▂▁▁▁▁76.29476.95777.44678.03678.56679.5222.953.9175.0136.1630.00.00.00.0
us-gaap:OtherAssetsNoncurrent █████▇▆▄▃▂▂▂▂▁50.51649.76749.12950.94551.44647.72938.46427.83918.15916.07714.14912.84411.5887.03
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:AccountsPayableCurrent ▅▄▅▃▂▄█▂▂▆█▂▁▂97.85488.59197.96683.81379.90386.766113.3776.19776.429103.207115.87880.14370.55177.86
us-gaap:AccruedIncomeTaxesCurrent ▄█▄▄▆█▃▄▁▃▃▄▁▃15.14323.5513.81213.77218.53523.83711.97113.3827.00311.00411.02313.0746.91612.018
us-gaap:LiabilitiesCurrent ▅▅▆▅▄█▄▂▁▄▄▂▁▁572.473585.665627.083551.296486.902798.87482.173358.408307.03526.089509.084382.942297.88316.853
us-gaap:LongTermDebtCurrent ▅▇▇▇▃▁▆▇██▃▇▆▆60.27495.26595.34495.17335.2090.20275.10994.671104.396104.15829.98984.9474.78574.785
us-gaap:OperatingLeaseLiabilityCurrent ▃▃▃▃▂▃▄▆▇█▁▁▁▁1.2281.2131.1051.0810.9311.0712.1013.1714.2714.6560.00.00.00.0
us-gaap:OtherLiabilitiesCurrent ▄▅▆▅▆██▃▂▆▆▂▁▂43.94648.97852.3349.8754.32362.62462.70539.87336.61254.54354.49235.49732.93539.166
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:LongTermDebt █▇▇▇▇▇▅▆▆▁▁▃▂975.8955.9955.4955.4954.1954.2881.1900.7910.4736.6736.236809.594758.68NA
us-gaap:LongTermDebtNoncurrent ▇▆▆▆▇█▅▅▅▁▃▃▂▂915.501860.654860.081860.235918.887953.962805.955806.014806.001632.484706.247724.654683.895683.497
us-gaap:DeferredIncomeTaxLiabilitiesNet ██▇▃▃▄▃▁▂▂325.6328.112319.292296.516297.995300.168295.643284.625292.791293.662NANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▁▃▅▁▅▇█▄▅▆▆▄▅▆203.854210.811217.287202.938218.493224.49228.129215.007217.909220.732221.886212.249218.061221.732
us-gaap:OtherLiabilitiesNoncurrent ▁▁▂▂▂▁▂▂▄▂█▆▆▆117.659118.989120.767123.041120.852119.033123.388123.352129.835120.569147.763140.475140.163137.147
us-gaap:OperatingLeaseLiabilityNoncurrent ██████▁▁▁▁▁▁▁▁80.08880.41480.62180.85480.15979.1050.8410.7320.7211.4950.00.00.00.0
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo ██████▁▃▃▃6.9926.9926.9166.8136.8136.7780.1952.1152.0822.082NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree ██████▁▁▁▁7.1567.1566.9866.8676.8666.8660.1290.1540.1290.129NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour ██████▁▁▁▁7.1917.1917.156.9866.9836.9830.0880.0930.0930.093NANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive NANA7.1857.157.1467.1460.0890.0710.0710.071NANANANA
 us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive dei:LegalEntity nwn:NorthwestNaturalGasCompanyNANA7.1857.157.1467.1460.0890.0710.0710.0717.304NANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive ██████▁▁▁▁123.808123.808123.784130.969130.912130.9350.5260.4970.4970.497NANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:StockholdersEquity ██▆▅▆▇▆▅▆▃▂▁▂▂922.826936.324888.733852.775884.001901.741865.999844.669876.746794.227762.634737.581759.526772.205
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest ██▆▅▆▇▆▅▆▃▂▁▂▂922.826936.324888.733852.775884.001901.741865.999844.669876.746794.227762.634737.581759.526772.205
us-gaap:CommonStockValue ██████▇▇▇▂▁▁▁▁569.785568.066565.112563.852562.766561.264558.282556.623555.052459.932457.64455.499452.195450.408
us-gaap:RetainedEarningsAccumulatedDeficit ▇█▅▂▄▆▃▁▄▅▃▁▃▄365.501380.939336.523299.15331.648351.05318.45296.256330.018342.734312.182290.059315.462330.081
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▂▁▁▄▄▄▄▇▇▆█▇▇▇-12.46-12.681-12.902-10.227-10.413-10.573-10.733-8.21-8.324-8.439-7.188-7.977-8.131-8.284
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity nwn:NorthwestNaturalGasCompany▂▁▁▄▄▄▄▇▇▆█▇▇▇-12.46-12.681-12.902-10.227-10.413-10.573-10.733-8.21-8.324-8.439-7.188-7.977-8.131-8.284
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity,us-gaap:RetirementPlanType nwn:NorthwestHoldingsandNorthwestNatural,nwn:NonQualifiedPensionPlansDefinedBenefitNANA12.902NANANA-10.733NANANA-7.188NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▄█▁▁▄▆▃▂▄▆▂▁▄▆57.216137.065-5.52-11.00656.683102.86330.0070.18250.315104.79410.242-4.12358.131104.521
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▆▅▅▆▁▄▅▁▇▇▆█▆-64.008-63.875-67.512-66.346-58.99-101.429-78.491-71.893-102.341-51.056-56.378-58.617-44.97-57.488
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity nwn:NorthwestNaturalGasCompany▅▄▂▃▆▅▂▃█▇▅▁█▅-60.658-62.229-75.512-71.039-55.932-61.64-75.702-71.311-45.415-50.649-57.264-78.739-44.972-57.487
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▃▅▄▁█▄▄▅▃▄▅▄▄9.59-83.13267.274-23.779-331.715459.99747.6121.348100.094-53.55428.80483.95-15.621-39.29
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:DepreciationDepletionAndAmortization █▁28.14428.097NA25.93425.83624.675NA23.37522.38721.572NANANANA
us-gaap:IncreaseDecreaseInAccountsPayable ▂▃▄▃▄▁▅▃▂▂█▄▃▁-14.91-2.3294.401-1.3924.511-23.4315.282-3.924-12.96-14.88339.7213.684-7.571-19.042
 us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity nwn:NorthwestNaturalGasCompany▁▄▄▄▄▁▅▃▃▂█▄▃▁-19.225-0.7113.794-0.5170.531-22.71711.733-6.537-8.407-15.33736.6753.457-7.55-18.645
us-gaap:IncreaseDecreaseInInventories ▇▂▄▅▆▃▅█▆▁▃▇▆▂12.788-16.454-2.3881.0749.623-9.5712.67618.2226.179-21.108-8.3419.9378.341-13.144
us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet ▇▃▃▅▅▆▃▄█▁▂▅▅▃11.196-2.166-1.6054.0963.356.626-2.4281.91613.691-8.894-4.142.5984.953-3.963
us-gaap:NetCashProvidedByUsedInOperatingActivities ▄█▁▁▄▆▃▂▄▆▂▁▄▆57.216137.065-5.52-11.00656.683102.86330.0070.18250.315104.79410.242-4.12358.131104.521
us-gaap:NetIncomeLoss ▃█▇▁▂▇▆▁▃▇▆▂▃▆-0.72459.51752.047-17.912-4.85247.49836.74-19.3011.09543.20135.824-11.794-0.99841.537
 us-gaap:NetIncomeLoss dei:LegalEntity nwn:NorthwestNaturalGasCompany▃█▇▁▂▇▆▁▃▇▆▂▃▆0.58960.11146.316-20.22-4.71249.17939.613-17.5883.05443.89537.581-11.794-0.99841.537
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:StatementEquityComponents nwn:NorthwestNaturalGasCompany,us-gaap:RetainedEarnings▁█0.58960.111NA-20.22-4.71249.179NA-17.5883.05443.895NA-11.794-0.99841.537
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▁█-0.72459.517NA-17.912-4.85247.498NA-19.3011.09543.201NA-11.794-0.99841.537
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▆▅▅▆▁▄▅▁▇▇▆█▆-64.008-63.875-67.512-66.346-58.99-101.429-78.491-71.893-102.341-51.056-56.378-58.617-44.97-57.488
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity nwn:NorthwestNaturalGasCompany▅▄▂▃▆▅▂▃█▇▅▁█▅-60.658-62.229-75.512-71.039-55.932-61.64-75.702-71.311-45.415-50.649-57.264-78.739-44.972-57.487
 us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidatedEntities srt:ParentCompany▅▅█▆▅▄▆▅▁▂▄▄▁▄64.40665.70279.6871.05464.83657.44670.47861.84642.38348.76455.84156.42545.04157.329
 us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:OtherNorthwestHoldings█▄▆▃▇▄▃▂▂▁▂▁▁▁3.3371.6042.1850.7282.8431.2121.0130.6060.3660.1060.3080.00.00.0
 us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:OtherNorthwestNatural▅▂▅▇▄▂▅▅▂▂▁▄█▄0.6930.1060.561.1130.5210.0770.6990.6440.1050.052-0.1810.5111.240.435
 us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NaturalGasDistribution▅▅█▆▅▄▆▅▁▂▄▄▁▄60.37663.99276.93569.21361.47256.15768.76660.59641.91248.60655.71455.91443.80156.894
 us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,nwn:NorthwestNaturalGasCompany▅▅█▇▅▄▆▅▁▂▄▄▂▄61.06964.09877.49570.32661.99356.23469.46561.2442.01748.65855.53356.42545.04157.329
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▃▅▄▁█▄▄▅▃▄▅▄▄9.59-83.13267.274-23.779-331.715459.99747.6121.348100.094-53.55428.80483.95-15.621-39.29
us-gaap:ProceedsFromIssuanceOfLongTermDebt NANA0.00.00.0150.00.00.0175.00.00.050.0NANA
 us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity nwn:NorthwestNaturalGasCompanyNANA0.00.00.0150.00.00.0140.00.00.050.0NANA
us-gaap:RepaymentsOfLongTermDebt NANA0.00.00.075.020.010.00.00.075.00.00.022.0
 us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity nwn:NorthwestNaturalGasCompanyNANA0.00.00.075.020.010.00.00.075.00.00.022.0
us-gaap:PaymentsOfDividendsCommonStock █▇█▇▇▇▇▆▂▂▂▁▁▁13.98413.85813.91213.82913.84513.83413.73413.68912.98112.93512.92412.8112.79612.781
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note2822SeriesDue2027NANA2.8220000000000003e-06NANANA2.8199999999999998e-08NANANA2.8199999999999998e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3141SeriesDue2029NANA3.141e-06NANANA3.1399999999999997e-083.141e-083.141e-08NANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3176SeriesDue2021NANA3.176e-06NANANA3.18e-08NANANA3.18e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3211SeriesDue2026NANA3.211e-06NANANA3.2099999999999996e-08NANANA3.2099999999999996e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3542SeriesDue2023NANA3.5419999999999997e-06NANANA3.54e-08NANANA3.54e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3600SeriesDue2050NANA3.6000000000000003e-06NANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3685SeriesDue2047NANA3.685e-06NANANA3.69e-08NANANA3.69e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note3869SeriesDue2049NANA3.8690000000000006e-06NANANA3.8699999999999996e-083.8690000000000004e-083.8690000000000004e-08NANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note4000SeriesDue2042NANA4e-06NANANA4e-08NANANA4e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note4110SeriesDue2048NANA4.1100000000000005e-06NANANA4.11e-08NANANA4.11e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note4136SeriesDue2046NANA4.136e-06NANANA4.14e-08NANANA4.14e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note5250SeriesDue2035NANA5.25e-06NANANA5.25e-08NANANA5.25e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note5370SeriesDue2020NANA5.37e-06NANANA5.37e-08NANANA5.37e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note537SeriesDue2020NANANA5.37e-065.37e-085.37e-08NANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note5620SeriesDue2023NANA5.62e-06NANANA5.62e-08NANANA5.62e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note5660SeriesDue2033NANA5.66e-06NANANA5.66e-08NANANA5.66e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note5820SeriesDue2032NANA5.82e-06NANANA5.8200000000000005e-08NANANA5.8200000000000005e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note6520SeriesDue2025NANA6.519999999999999e-06NANANA6.519999999999999e-08NANANA6.519999999999999e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note6650SeriesDue2027NANA6.650000000000001e-06NANANA6.65e-08NANANA6.65e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note6650SeriesDue2028NANA6.650000000000001e-06NANANA6.65e-08NANANA6.65e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note7000SeriesDue2027NANA7e-06NANANA7e-08NANANA7e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note7050SeriesDue2026NANA7.049999999999999e-06NANANA7.049999999999999e-08NANANA7.049999999999999e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note7720SeriesDue2025NANA7.719999999999999e-06NANANA7.72e-08NANANA7.72e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note7740SeriesDue2030NANA7.74e-06NANANA7.739999999999999e-08NANANA7.739999999999999e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note7850SeriesDue2030NANA7.85e-06NANANA7.85e-08NANANA7.85e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage dei:LegalEntity,us-gaap:DebtInstrument nwn:NorthwestNaturalGasCompany,nwn:Note9050SeriesDue2021NANA9.050000000000001e-06NANANA9.05e-08NANANA9.05e-08NANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:ConsolidationItems,us-gaap:DebtInstrument,us-gaap:StatementBusinessSegments us-gaap:CorporateNonSegment,nwn:NWNWaterTermLoanDue2021,nwn:OtherNorthwestHoldingsNANA7e-07NANANA2.35e-08NANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument nwn:FiveYearTermLoanDue20269.000000000000001e-07NANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument nwn:TwoyearTermLoanDue2021NA6.6e-07NA7.4e-077.3e-091.82e-08NA2.65e-082.86e-08NANANANANA

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value569568565563562561558556555459457455452450448447
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets15.115.115.015.615.514.016.317.117.114.414.114.815.114.914.814.4

us-gaap:CommonStockValue dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value319319319319319319319319319226226455452450448
Percentage of CommonStockValue56.156.256.556.756.856.957.257.457.649.249.5100.0100.0100.0100.0
Percentage of Assets8.48.58.58.88.88.09.39.89.97.17.014.815.114.914.8
Percentage of Assets nwn:NorthwestNaturalGasCompany8.88.88.99.29.28.49.610.110.27.27.114.815.114.814.7

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Common
Period End2020-12-312019-12-312018-12-31
Value847840739
Percentage of CommonStockValue149.9150.5161.6
Percentage of Assets22.624.522.8
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet86.693.895.9

Common Stock Shares Issued

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesIssued


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value30303030303030303028282828282828
Percentage of CommonStockSharesIssued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding

us-gaap:CommonStockSharesOutstanding


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value30303030303030303028282828282828
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents

us-gaap:CommonStock


Common
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value303028282827
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.00.00.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value3030303030303029282828282828282828
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value3030303030303029282828282828282828
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount


Antidilutive
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value48000.012000.047000.041000.03000.069000.01000.05000.073000.053000.016000.096000.0
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.021.941.7-0.59-0.161.561.21-0.630.041.491.24-0.41-0.031.44-3.14-0.30.11.41
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.021.941.7-0.59-0.161.561.2-0.630.041.491.24-0.41-0.031.44-3.13-0.30.11.4
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Basic Share

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.021.941.5-0.61-0.171.581.26-0.610.071.51.27-0.39-0.011.461.2-0.280.141.45
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Diluted Share

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.021.941.5-0.61-0.171.581.26-0.610.071.51.27-0.39-0.011.461.2-0.280.141.44
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-0.5035949-17.726-4.6924734-19.1871.214336-11.64-0.84541-92.077-8.345
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.419.20.0-20.1-3.817.00.0-21.81.014.30.0-13.1-0.715.80.00.0

us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.816043-20.034-4.5524937-17.4743.1694438-11.64-0.84541
Percentage of ComprehensiveIncomeNetOfTax-161.0101.088.4113.097.0103.5108.491.1261.9101.6104.8100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.619.40.0-22.7-3.617.60.0-19.92.714.50.0-13.1-0.715.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:AccumulatedOtherComprehensiveIncome


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.2210.221-2.6750.1860.160.16-2.5230.1140.1150.1150.7890.1540.1530.154
Percentage of ComprehensiveIncomeNetOfTax-43.90.4-5.4-1.0-3.40.3-7.4-0.69.50.32.2-1.3-18.10.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.10.00.20.10.10.00.10.10.00.00.20.10.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ComprehensiveIncomeNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.2210.221-2.6750.1860.160.16-2.5230.1140.1150.1150.7890.1540.1530.154
Percentage of ComprehensiveIncomeNetOfTax-43.90.4-5.4-1.0-3.40.3-7.4-0.69.50.32.2-1.3-18.10.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.10.00.20.10.10.00.10.10.00.00.20.10.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Gross Profit

us-gaap:GrossProfit us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:GrossProfit

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Gross
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value91172148557915413355801521265469132
Percentage of GrossProfit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax68.355.50.062.963.754.90.063.568.950.50.062.157.750.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations

us-gaap:IncomeLossFromContinuingOperations

us-gaap:IncomeLossFromContinuingOperations


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.7245945-18.677-5.1324838-18.5062.0514336-11.144-0.3394234-7.8874.07541
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.519.10.0-21.2-4.117.20.0-21.01.714.40.0-12.6-0.315.90.00.00.00.0

us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidatedEntities

srt:ParentCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.7245945-18.677-5.1324838-18.5062.0514336-11.144-0.33942
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.519.10.0-21.2-4.117.20.0-21.01.714.40.0-12.6-0.315.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:ParentCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1.313-0.594-0.511.543-0.42-0.903-1.265-0.918-1.003-0.477-0.7980.131-0.068-0.003
Percentage of IncomeLossFromContinuingOperations181.4-1.0-1.1-8.38.2-1.9-3.35.0-48.9-1.1-2.2-1.220.1-0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.0-0.20.01.7-0.3-0.30.0-1.0-0.9-0.20.00.1-0.1-0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.976.1862.2371.91.6351.2361.6331.9821.8422.6895.020.7082.6992.131
Percentage of IncomeLossFromContinuingOperations-272.110.44.9-10.2-31.92.64.3-10.789.86.213.6-6.4-796.25.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.52.00.02.21.30.40.02.31.60.90.00.82.20.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1.3815344-22.12-6.3474737-19.571.2124132-11.983-2.9739
Percentage of IncomeLossFromContinuingOperations190.790.696.2118.4123.799.399.0105.759.194.988.5107.5876.194.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.017.30.0-25.1-5.117.10.0-22.21.013.60.0-13.5-2.515.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.5896046-20.22-4.7124939-17.5883.0544337-11.275-0.27142
Percentage of IncomeLossFromContinuingOperations-81.4101.0101.1108.391.8101.9103.395.0148.9101.1102.2101.279.9100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.419.30.0-22.9-3.817.50.0-20.02.614.50.0-12.7-0.215.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-1.0018059-24.04-6.8046246-22.8492.6765249-15.429-0.4955751-13.609
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.825.70.0-27.2-5.422.20.0-26.02.317.20.0-17.4-0.421.80.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.8778060-26.277-6.1316347-21.6014.0395250-15.608-0.39957
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest-87.6100.8101.1109.390.1101.9104.094.5150.9101.2102.2101.280.6100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.725.90.0-29.8-4.922.60.0-24.63.417.40.0-17.6-0.321.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-0.2772013-5.363-1.672147.685-4.3430.6258.67513-4.285-0.1561516-5.722
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.26.60.0-6.1-1.35.00.0-4.90.52.90.0-4.8-0.15.90.00.0

us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.2882014-6.057-1.419148.245-4.0130.9858.84813-4.333-0.12815
Percentage of IncomeTaxExpenseBenefit-104.0100.2101.2112.984.9102.1107.392.4157.6102.0102.2101.182.1100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.26.60.0-6.9-1.15.10.0-4.60.82.90.0-4.9-0.15.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet

us-gaap:IncomeTaxesPaidNet


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value6.6050.84.38.80.8-0.2566.0-0.001-6.005-0.095.3238.73.5479.83.199
Percentage of IncomeTaxesPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.90.30.010.00.6-0.10.0-0.0-5.1-0.00.09.82.93.70.0

us-gaap:IncomeTaxesPaidNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.032.885.150.00.00.958.575-0.001-6.005-0.095.3038.73.5479.8
Percentage of IncomeTaxesPaidNet121.6360.0119.80.00.0-371.1142.9100.0100.0100.099.6100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.00.90.00.00.00.30.0-0.0-5.1-0.00.09.82.93.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Income Expense Nonoperating Net

us-gaap:InterestIncomeExpenseNonoperatingNet

us-gaap:InterestIncomeExpenseNonoperatingNet


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
Value-11028000.0-11126000.0-10713000.0-9165000.0-12706000.0-10468000.0-10878000.0-10948000.0-10654000.0-10205000.0-10008000.0-9006000.0-8771000.0-9274000.0-9215000.0-9208000.0
Percentage of InterestIncomeExpenseNonoperatingNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-8.3-3.60.0-10.4-10.2-3.70.0-12.4-9.1-3.40.0-10.2-7.3-3.50.00.0

us-gaap:InterestIncomeExpenseNonoperatingNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-10696000.0-10790000.0-10348000.0-8806000.0-11851000.0-9861000.0-10360000.0-10459000.0-10387000.0-10133000.0-9940000.0-9007000.0-8771000.0-9274000.0
Percentage of InterestIncomeExpenseNonoperatingNet97.097.096.696.193.394.295.295.597.599.399.3100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-8.0-3.50.0-10.0-9.5-3.50.0-11.9-8.8-3.30.0-10.2-7.3-3.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Paid Net

us-gaap:InterestPaidNet

us-gaap:InterestPaidNet


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value128.976126.673148.368138.011117.97612
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.72.90.07.611.83.00.09.110.02.60.0

us-gaap:InterestPaidNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value128.585126.345137.795137.398117.88912
Percentage of InterestPaidNet97.795.697.495.194.793.296.392.399.198.999.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.52.80.07.211.22.80.08.49.92.60.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.7245952-17.912-4.8524736-19.3011.0954335-11.794-0.99841-90.167-8.4952.72940
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.519.10.0-20.3-3.916.90.0-21.90.914.30.0-13.3-0.815.70.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value0.5896046-20.22-4.7124939-17.5883.0544337-11.794-0.99841-90.167-8.4952.72940
Percentage of NetIncomeLoss-81.4101.089.0112.997.1103.5107.891.1278.9101.6104.9100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.419.30.0-22.9-3.817.50.0-20.02.614.50.0-13.3-0.815.70.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.58960-20.22-4.71249-17.5883.05443-11.794-0.99841
Percentage of NetIncomeLoss-81.4101.0112.997.1103.591.1278.9101.6100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.419.3-22.9-3.817.5-20.02.614.5-13.3-0.815.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-0.72459-17.912-4.85247-19.3011.09543-11.794-0.99841
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.519.1-20.3-3.916.9-21.90.914.3-13.3-0.815.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

Operating Costs And Expenses

us-gaap:OperatingCostsAndExpenses

us-gaap:OperatingCostsAndExpenses


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value50524541434846403951-252.834973839-273.07990
Percentage of OperatingCostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax37.516.80.046.835.217.40.046.533.617.00.0110.031.515.00.00.0

Operating Expenses

us-gaap:OperatingExpenses

us-gaap:OperatingExpenses


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1362211851041262081869910720916497116195
Percentage of OperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax102.171.10.0118.8100.874.30.0113.691.369.20.0110.096.374.2

us-gaap:OperatingExpenses dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1302171811011222051829610520816297116195
Percentage of OperatingExpenses95.798.297.797.197.098.598.296.597.899.599.1100.299.9100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax97.869.80.0115.497.873.10.0109.689.368.80.0110.296.274.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value129474-11.5888.9427660-9.634167662-6.1118.2696759-4.54
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.530.40.0-13.17.227.20.0-11.013.725.10.0-6.96.825.70.00.0

us-gaap:OperatingIncomeLoss dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value149575-13.4698.8997762-8.819177663-6.2818.40567
Percentage of OperatingIncomeLoss112.0100.4100.9116.299.5100.8102.291.5107.1100.8101.6102.8101.6100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.630.60.0-15.37.127.40.0-10.014.725.30.0-7.17.025.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingIncomeLoss us-gaap:ConsolidatedEntities

srt:ParentCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value129474-11.5888.9427660-9.634167662-6.1118.26967
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.530.40.0-13.17.227.20.0-11.013.725.10.0-6.96.825.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:ParentCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1.515-0.412-0.6381.8810.043-0.575-1.316-0.815-1.142-0.599-0.9840.17-0.1360.013
Percentage of OperatingIncomeLoss-12.0-0.4-0.9-16.20.5-0.8-2.28.5-7.1-0.8-1.6-2.8-1.60.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.1-0.10.02.10.0-0.20.0-0.9-1.0-0.20.00.2-0.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.8088.6312.9612.7272.4651.7632.3382.7612.5833.7464.6633.4993.862.982
Percentage of OperatingIncomeLoss22.29.14.0-23.527.62.33.8-28.716.04.97.5-57.346.74.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.12.80.03.12.00.60.03.12.21.20.04.03.21.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value118672-16.1966.4347559-11.58147258-9.784.54564
Percentage of OperatingIncomeLoss89.891.396.9139.872.098.498.3120.291.095.994.1160.055.095.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.527.80.0-18.35.126.80.0-13.212.524.10.0-11.03.824.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value149575-13.4698.8997762-8.819177663-6.2818.40567
Percentage of OperatingIncomeLoss112.0100.4100.9116.299.5100.8102.291.5107.1100.8101.6102.8101.6100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.630.60.0-15.37.127.40.0-10.014.725.30.0-7.17.025.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-2597000.0-3542000.0-4042000.0-3287000.0-3040000.0-3575000.0-4054000.0-2267000.0-2768000.0-13747000.0-2462000.0-312000.07000.0-834000.0329000.0139000.0
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.9-1.10.0-3.7-2.4-1.30.0-2.6-2.4-4.50.0-0.40.0-0.30.00.0

us-gaap:OtherNonoperatingIncomeExpense dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value-2566000.0-3665000.0-4372000.0-4002000.0-3179000.0-3563000.0-4063000.0-2323000.0-2814000.0-13768000.0-2431000.0-320000.0-33000.0-815000.0
Percentage of OtherNonoperatingIncomeExpense98.8103.5108.2121.8104.699.7100.2102.5101.7100.298.7102.6-471.497.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.9-1.20.0-4.5-2.5-1.30.0-2.6-2.4-4.60.0-0.4-0.0-0.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Regulated Operating Revenue

us-gaap:RegulatedOperatingRevenue us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:RegulatedOperatingRevenue

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Regulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value134296246791222732357711527821984118
Percentage of RegulatedOperatingRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax101.195.30.089.997.797.40.088.698.592.20.096.098.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

nwn:NorthwestNaturalGasCompany, us-gaap:CorporateNonSegment, nwn:ApplianceCenterRevenue, nwn:OtherNorthwestNatural, us-gaap:TransferredAtPointInTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.3431.5891.8381.1850.8061.5561.9090.9881.0581.5161.8581.0211.1711.546
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.50.01.30.60.60.01.10.90.50.01.21.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:CorporateNonSegment nwn:ApplianceCenterRevenue nwn:OtherNorthwestNatural us-gaap:TransferredAtPointInTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany, us-gaap:CorporateNonSegment, nwn:AssetManagementRevenueNetofRegulatorySharing, nwn:OtherNorthwestNatural, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.8176.9280.5330.9390.910.150.5311.2080.461.5061.5742.7142.141.579
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax60.8436.029.079.2112.99.627.8122.343.599.384.7265.8182.7102.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.62.20.01.10.70.10.01.40.40.50.03.11.80.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:CorporateNonSegment nwn:AssetManagementRevenueNetofRegulatorySharing nwn:OtherNorthwestNatural us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany, us-gaap:CorporateNonSegment, nwn:GasStorageRevenueNetofRegulatorySharing, nwn:OtherNorthwestNatural, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.8052.4952.4922.4822.4492.3362.3842.3332.742.7833.5912.4152.7372.577
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax208.9157.0135.6209.5303.8150.1124.9236.1259.0183.6193.3236.5233.7166.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.80.02.82.00.80.02.72.30.90.02.72.31.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:CorporateNonSegment nwn:GasStorageRevenueNetofRegulatorySharing nwn:OtherNorthwestNatural us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.965114.8634.6064.1654.0424.8244.5294.2585.8057.0236.156.0485.702
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax369.7693.0264.6388.7516.7259.8252.7458.4402.5382.9378.0602.4516.5368.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.73.50.05.23.31.40.05.13.61.90.06.95.02.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:CorporateNonSegment nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService

us-gaap:CorporateNonSegment, nwn:Otherrevenue, nwn:OtherNorthwestHoldings, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.3383.5963.5784.9173.8142.6222.02.7251.2010.5020.5560.0120.0040.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax323.0226.3194.7414.9473.2168.5104.8275.8113.533.129.91.20.30.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.31.20.05.63.10.90.03.11.00.20.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:Otherrevenue nwn:OtherNorthwestHoldings us-gaap:TransferredOverTime0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.3383.5963.5784.9173.8142.6222.02.7251.2010.5020.5560.0120.0040.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax323.0226.3194.7414.9473.2168.5104.8275.8113.533.129.91.20.30.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.31.20.05.63.10.90.03.11.00.20.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value133311250881242812478711730222288120263
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService

nwn:NorthwestNaturalGasCompany, us-gaap:OperatingSegments, nwn:NaturalGasSales, nwn:NaturalGasDistribution, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value123296241781162742408011229621582114258
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.795.296.588.893.497.597.091.595.397.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.795.296.588.893.497.597.091.595.397.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:OperatingSegments nwn:NaturalGasSales nwn:NaturalGasDistribution us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, us-gaap:OperatingSegments, nwn:Otherrevenue, nwn:NaturalGasDistribution, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.3990.4150.3350.3330.3320.3370.4960.2470.1040.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.30.10.10.40.30.10.20.30.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.30.10.10.40.30.10.20.30.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:OperatingSegments nwn:Otherrevenue nwn:NaturalGasDistribution us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value124296241781172742418011229621582114258
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax93.095.396.689.293.697.697.291.895.497.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax93.095.396.689.293.697.697.291.895.497.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:OperatingSegments nwn:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax dei:LegalEntity, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments, us-gaap:TimingOfTransferOfGoodOrService

nwn:NorthwestNaturalGasCompany, nwn:ApplianceCenterRevenue, nwn:NorthwestNaturalGasCompany, us-gaap:TransferredAtPointInTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.3431.5891.8381.1850.8061.5561.9090.9881.0581.5161.8581.0211.1711.546
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.50.71.30.60.60.81.10.90.50.81.21.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.50.71.30.60.60.81.10.90.50.81.21.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:ApplianceCenterRevenue nwn:NorthwestNaturalGasCompany us-gaap:TransferredAtPointInTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:AssetManagementRevenueNetofRegulatorySharing, nwn:NorthwestNaturalGasCompany, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.8176.9280.5330.9390.910.150.5311.2080.461.5061.5742.7142.141.579
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.62.20.21.10.70.10.21.40.40.50.73.11.80.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.62.20.21.10.70.10.21.40.40.50.73.11.80.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:AssetManagementRevenueNetofRegulatorySharing nwn:NorthwestNaturalGasCompany us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:GasStorageRevenueNetofRegulatorySharing, nwn:NorthwestNaturalGasCompany, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.8052.4952.4922.4822.4492.3362.3842.3332.742.7833.5912.4152.7372.577
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.81.02.82.00.81.02.72.30.91.62.72.31.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.81.02.82.00.81.02.72.30.91.62.72.31.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:GasStorageRevenueNetofRegulatorySharing nwn:NorthwestNaturalGasCompany us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:NaturalGasSales, nwn:NorthwestNaturalGasCompany, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value123296241781162742408011229621582114258
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.795.296.588.893.497.597.091.595.397.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.795.296.588.893.497.597.091.595.397.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:NaturalGasSales nwn:NorthwestNaturalGasCompany us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:Otherrevenue, nwn:NorthwestNaturalGasCompany, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.3990.4150.3350.3330.3320.3370.4960.2470.1040.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.30.10.10.40.30.10.20.30.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.30.10.10.40.30.10.20.30.10.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:Otherrevenue nwn:NorthwestNaturalGasCompany us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, nwn:NorthwestNaturalGasCompany


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value129307246831212782458511630122288120263
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax96.798.898.694.496.999.199.296.999.099.899.8100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax96.798.898.694.496.999.199.296.999.099.899.8100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:NorthwestNaturalGasCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService, us-gaap:TimingOfTransferOfGoodOrService

nwn:ApplianceCenterRevenue, us-gaap:TransferredAtPointInTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.3431.5891.8381.1850.8061.5561.9090.9881.0581.5161.8581.0211.1711.546
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.50.71.30.60.60.81.10.90.50.81.21.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.00.50.71.30.60.60.81.10.90.50.81.21.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:ApplianceCenterRevenue us-gaap:TransferredAtPointInTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:AssetManagementRevenueNetofRegulatorySharing, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.8176.9280.5330.9390.910.150.5311.2080.461.5061.5742.7142.141.579
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.62.20.21.10.70.10.21.40.40.50.73.11.80.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.62.20.21.10.70.10.21.40.40.50.73.11.80.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:AssetManagementRevenueNetofRegulatorySharing us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:GasStorageRevenueNetofRegulatorySharing, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.8052.4952.4922.4822.4492.3362.3842.3332.742.7833.5912.4152.7372.577
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.81.02.82.00.81.02.72.30.91.62.72.31.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.81.02.82.00.81.02.72.30.91.62.72.31.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:GasStorageRevenueNetofRegulatorySharing us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NaturalGasSales, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value123296241781162742408011229621582114258
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.795.296.588.893.497.597.091.595.397.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.795.296.588.893.497.597.091.595.397.996.693.095.097.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NaturalGasSales us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:Otherrevenue, us-gaap:TransferredOverTime


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.7374.0113.9135.254.1462.9592.4962.9721.3050.5020.5560.0120.0040.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.51.31.65.93.31.11.03.41.10.20.20.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.51.31.65.93.31.11.03.41.10.20.20.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:Otherrevenue us-gaap:TransferredOverTime100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value14831526093134285247901232852269112426323886134295
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax111.6101.6104.1105.7108.0101.599.7102.7105.094.3101.7103.1103.199.90.00.00.00.0

us-gaap:Revenues dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value14431225688131282245871222842269112426323886134295
Percentage of Revenues97.198.998.694.797.299.199.297.099.099.899.8100.0100.0100.0100.199.9100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax108.3100.4102.6100.1104.9100.598.999.6104.094.2101.4103.1103.199.90.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:OperatingSegments, nwn:Alternativerevenue, nwn:NaturalGasDistribution


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value110.4535.5820.3955.365-0.472-4.858-2.6073.733-17.2533.7041.9943.663-0.372
Percentage of Revenues7.40.12.10.44.0-0.2-2.0-2.93.0-6.01.62.22.9-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.30.12.20.44.3-0.2-2.0-3.03.2-5.71.72.33.0-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:OperatingSegments nwn:Alternativerevenue nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.965114.8634.6064.1654.0424.8244.5294.2585.8057.0236.156.0485.702
Percentage of Revenues3.33.51.94.93.11.42.05.03.42.03.16.74.92.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.73.51.95.23.31.41.95.13.61.93.26.95.02.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:CorporateNonSegment nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany, us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value139301251831262782408311727921985118257
Percentage of Revenues93.895.496.889.894.197.797.292.095.697.896.793.295.197.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax104.696.9100.794.9101.699.197.094.4100.392.298.396.198.197.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:OperatingSegments nwn:NaturalGasDistribution112.5101.6104.2106.3108.5101.599.7102.9105.294.2101.8103.3103.399.9

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

nwn:NorthwestNaturalGasCompany, nwn:Alternativerevenue, nwn:NorthwestNaturalGasCompany


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value110.4535.5820.3955.365-0.472-4.858-2.6073.733-17.2533.7041.9943.663-0.372
Percentage of Revenues7.40.12.10.44.0-0.2-2.0-2.93.0-6.01.62.22.9-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.30.12.20.44.3-0.2-2.0-3.03.2-5.71.72.33.0-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:Alternativerevenue nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, nwn:NorthwestNaturalGasCompany


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value144312256881312822458712228422691124263
Percentage of Revenues97.198.998.694.797.299.199.297.099.099.899.8100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax108.3100.4102.6100.1104.9100.598.999.6104.094.2101.4103.1103.199.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany nwn:NorthwestNaturalGasCompany112.0101.6104.1106.0108.2101.599.7102.7105.094.3101.7103.1103.199.9

us-gaap:Revenues us-gaap:ConsolidatedEntities

srt:ParentCompany


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value148315260931342852479012328522691124263
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax111.6101.6104.1105.7108.0101.599.7102.7105.094.3101.7103.1103.199.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:ParentCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.3383.5963.5784.9173.8142.6222.02.7251.2010.5020.5560.0120.0040.0
Percentage of Revenues2.91.11.45.32.80.90.83.01.00.20.20.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.31.21.45.63.10.90.83.11.00.20.20.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.965114.8634.6064.1654.0424.8244.5294.2585.8057.0236.156.0485.702
Percentage of Revenues3.33.51.94.93.11.42.05.03.42.03.16.74.92.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.73.51.95.23.31.41.95.13.61.93.26.95.02.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value139301251831262782408311727921985118257
Percentage of Revenues93.895.496.889.894.197.797.292.095.697.896.793.295.197.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax104.696.9100.794.9101.699.197.094.4100.392.298.396.198.197.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, nwn:NorthwestNaturalGasCompany


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value144312256881312822458712228422691124263
Percentage of Revenues97.198.998.694.797.299.199.297.099.099.899.8100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax108.3100.4102.6100.1104.9100.598.999.6104.094.2101.4103.1103.199.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Revenues us-gaap:ProductOrService

nwn:Alternativerevenue


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value110.4535.5820.3955.365-0.472-4.858-2.6073.733-17.2533.7041.9943.663-0.372
Percentage of Revenues7.40.12.10.44.0-0.2-2.0-2.93.0-6.01.62.22.9-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.30.12.20.44.3-0.2-2.0-3.03.2-5.71.72.33.0-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:Alternativerevenue0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3783375837563618364140013428325132383191324230812986302930393105
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value363936193599346334803825332131493138314031923085299030333043
Percentage of Assets96.296.395.895.795.695.696.996.996.998.498.5100.1100.1100.1100.1
Percentage of Assets96.296.395.895.795.695.696.996.996.998.498.5100.1100.1100.1100.1
Percentage of Assets nwn:NorthwestNaturalGasCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-31
Value978895771
Percentage of Assets26.026.123.8
Percentage of Assets26.026.123.8
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet100.0100.0100.0

srt:ParentCompany


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3783375837563601362439863413323732243176322930682974301630252869
Percentage of Assets100.0100.0100.099.599.599.699.699.699.699.599.699.699.699.699.50.0
Percentage of Assets100.0100.0100.099.599.599.699.699.699.699.599.699.699.699.699.50.0
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value14413915713714416091878535364414131414
Percentage of Assets3.83.74.23.84.04.02.72.72.61.11.11.40.50.50.50.0
Percentage of Assets3.83.74.23.84.04.02.72.72.61.11.11.40.50.50.50.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value51494911104847484849505151505048
Percentage of Assets1.41.31.30.30.31.21.41.51.51.61.61.71.71.71.70.0
Percentage of Assets1.41.31.30.30.31.21.41.51.51.61.61.71.71.71.70.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestNatural100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3587357035493451347037763273310130893091314129722907295229612806
Percentage of Assets94.895.094.595.495.394.495.595.495.496.996.996.597.497.597.40.0
Percentage of Assets94.895.094.595.495.394.495.595.495.496.996.996.597.497.597.40.0
Percentage of Assets us-gaap:OperatingSegments nwn:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, nwn:NorthwestNaturalGasCompany


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3639361935993463348038253321314931383140319230242959300330112855
Percentage of Assets96.296.395.895.795.695.696.996.996.998.498.598.199.199.199.10.0
Percentage of Assets96.296.395.895.795.695.696.996.996.998.498.598.199.199.199.10.0
Percentage of Assets us-gaap:OperatingSegments nwn:NorthwestNaturalGasCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3783375837563618364140013428325132383191324230812986302930393105
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value363936193599346334803825332131493138314031923085299030333043
Percentage of LiabilitiesAndStockholdersEquity96.296.395.895.795.695.696.996.996.998.498.5100.1100.1100.1100.1
Percentage of Assets96.296.395.895.795.695.696.996.996.998.498.5100.1100.1100.1100.1
Percentage of Assets nwn:NorthwestNaturalGasCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Liabilities
Period End2020-12-312019-12-312018-12-31
Value978895771
Percentage of LiabilitiesAndStockholdersEquity26.026.123.8
Percentage of Assets26.026.123.8
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value922936888852884901865844876794762737759772742846
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.424.923.723.624.322.525.326.027.124.923.523.925.425.524.427.3

us-gaap:StockholdersEquity dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value868881835805839857822798830746715737759772742
Percentage of StockholdersEquity94.194.294.094.595.095.194.994.694.794.093.8100.0100.0100.0100.0
Percentage of Assets23.023.522.222.323.121.424.024.625.623.422.123.925.425.524.4
Percentage of Assets nwn:NorthwestNaturalGasCompany23.924.423.223.324.122.424.825.426.423.822.423.925.425.524.4

us-gaap:StockholdersEquity us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Stockholders
Period End2020-12-312019-12-312018-12-31
Value892867761
Percentage of StockholdersEquity100.4100.299.9
Percentage of Assets23.825.323.5
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet91.296.898.8

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value273302323242316720293202239272295218180241269199
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets7.28.18.66.78.718.08.66.27.48.59.17.16.18.08.96.4

us-gaap:AssetsCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value249281282203282667270183221248272210173245273
Percentage of AssetsCurrent91.393.087.583.889.192.792.090.392.791.492.296.796.1101.8101.5
Percentage of Assets6.67.57.55.67.716.77.95.66.87.88.46.85.88.19.0
Percentage of Assets nwn:NorthwestNaturalGasCompany6.97.87.95.98.117.58.15.87.17.98.56.85.88.19.0

us-gaap:AssetsCurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Assets
Period End2020-12-312019-12-312018-12-31
Value386.92515
Percentage of AssetsCurrent11.82.45.4
Percentage of Assets1.00.20.5
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet3.90.82.1

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312015-12-31
Value201730351374719.64810601212298.755113.472153.5214.211
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.50.81.03.811.80.30.31.90.40.41.00.30.40.10.50.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value111010271204325.9196.274576.8337.9478.8868.322103.113.383.978
Percentage of CashAndCashEquivalentsAtCarryingValue57.258.234.675.587.891.861.359.695.053.362.929.795.197.289.696.094.5
Percentage of Assets0.30.30.30.73.310.80.20.21.80.20.20.30.30.40.10.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany0.30.30.30.83.511.30.20.21.80.20.20.30.30.40.10.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Cash
Period End2020-12-312019-12-312018-12-31
Value110.1194.011
Percentage of CashAndCashEquivalentsAtCarryingValue37.31.231.8
Percentage of Assets0.30.00.1
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet1.20.00.5

nwn:ParentCompanyCondensedStatementofCashFlows


Cash
Period End2020-12-312019-12-312018-12-312017-12-31
Value110.1194.0110.0
Percentage of CashAndCashEquivalentsAtCarryingValue37.31.231.80.0
Percentage of Assets0.30.00.10.0
Percentage of Assets nwn:ParentCompanyCondensedStatementofCashFlows0.00.00.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-31
Value28253514247512
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.70.93.911.90.4

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Cash
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-31
Value1918151254378.907
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents69.670.644.488.291.870.5
Percentage of Assets0.50.50.43.510.90.3
Percentage of Assets nwn:NorthwestNaturalGasCompany0.50.50.43.611.40.3

Other Assets Current

us-gaap:OtherAssetsCurrent

us-gaap:OtherAssetsCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value22304425202638181820282011162417
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.81.20.70.60.71.10.60.60.60.90.70.40.60.80.6

us-gaap:OtherAssetsCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value223037202026331718192520111624
Percentage of OtherAssetsCurrent98.998.184.779.399.899.487.594.199.896.089.099.799.499.799.7
Percentage of Assets0.60.81.00.60.60.71.00.50.60.60.80.70.40.60.8
Percentage of Assets nwn:NorthwestNaturalGasCompany0.60.81.10.60.60.71.00.60.60.60.80.70.40.60.8

us-gaap:OtherAssetsCurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Other
Period End2020-12-312019-12-312018-12-31
Value6.2234.63.078
Percentage of OtherAssetsCurrent13.912.110.8
Percentage of Assets0.20.10.1
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet0.60.50.4

Assets Noncurrent

us-gaap:AssetsNoncurrent

us-gaap:AssetsNoncurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3509345534333375332432813134304829992919294628632805278727692906
Percentage of AssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets92.891.991.493.391.382.091.493.892.691.590.992.993.992.091.193.6

us-gaap:AssetsNoncurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value338933383316325931983157305129662917289129192874281727872769
Percentage of AssetsNoncurrent96.696.696.696.696.296.297.397.397.399.199.1100.4100.4100.0100.0
Percentage of Assets89.688.888.390.187.878.989.091.290.190.690.093.394.392.091.1
Percentage of Assets nwn:NorthwestNaturalGasCompany93.192.292.194.191.982.591.994.292.992.191.593.294.291.991.0

us-gaap:AssetsNoncurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Assets
Period End2020-12-312019-12-312018-12-31
Value940888755
Percentage of AssetsNoncurrent27.428.425.6
Percentage of Assets25.025.923.3
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet96.199.297.9

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3849378837343680360835513476341633553439341433703298325132043148
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets101.8100.899.4101.799.188.7101.4105.1103.6107.8105.3109.4110.4107.3105.4101.4

us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value379437363683363335643509345633973337343534103366329832503204
Percentage of PropertyPlantAndEquipmentGross98.698.698.798.798.898.899.499.499.499.999.999.9100.0100.0100.0
Percentage of Assets100.399.498.1100.497.987.7100.8104.5103.1107.7105.2109.3110.4107.3105.4
Percentage of Assets nwn:NorthwestNaturalGasCompany104.3103.2102.3104.9102.491.7104.1107.9106.3109.4106.8109.1110.3107.2105.3

us-gaap:PropertyPlantAndEquipmentGross us-gaap:StatementBusinessSegments

nwn:NaturalGasDistribution


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value362335943548344134043344330232363193315931343068303530032975
Percentage of PropertyPlantAndEquipmentGross94.194.995.093.594.394.295.094.795.291.991.891.092.092.492.8
Percentage of Assets95.895.694.595.193.583.696.399.598.699.096.799.6101.699.297.9
Percentage of Assets nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:OtherNorthwestHoldings


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value5451504744422019184.1564.0513.4910.3760.3750.375
Percentage of PropertyPlantAndEquipmentGross1.41.41.31.31.21.20.60.60.60.10.10.10.00.00.0
Percentage of Assets1.51.41.31.31.21.00.60.60.60.10.10.10.00.00.0
Percentage of Assets nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:OtherNorthwestNatural


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value666666656464636363656665656564
Percentage of PropertyPlantAndEquipmentGross1.71.81.81.81.81.81.81.91.91.91.92.02.02.02.0
Percentage of Assets1.81.81.81.81.81.61.91.92.02.02.02.12.22.22.1
Percentage of Assets nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1093109110791073106210501037102710161005993996984972960954
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.929.128.729.729.226.330.331.631.431.530.632.433.032.131.630.7

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value1088108710751070105910491036102610151004992996984972960
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment99.599.699.699.799.899.899.999.9100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.828.928.629.629.126.230.231.631.431.530.632.333.032.131.6
Percentage of Assets nwn:NorthwestNaturalGasCompany29.930.029.930.930.427.431.232.632.432.031.132.332.932.131.6

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:StatementBusinessSegments

nwn:NaturalGasDistribution


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value10681067105510511040103010171007997985974978966954942
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment97.797.897.897.998.098.098.198.198.198.198.198.198.198.298.2
Percentage of Assets28.228.428.129.028.625.729.731.030.830.930.031.832.431.531.0
Percentage of Assets nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:OtherNorthwestHoldings


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value5.124.5123.8233.2182.5391.7151.2540.6990.4240.3050.2630.2130.2080.20.192
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment0.50.40.40.30.20.20.10.10.00.00.00.00.00.00.0
Percentage of Assets0.10.10.10.10.10.00.00.00.00.00.00.00.00.00.0
Percentage of Assets nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:OtherNorthwestNatural


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value201919191918181818181818181717
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment1.81.81.81.81.81.81.81.81.81.91.91.81.81.81.8
Percentage of Assets0.50.50.50.50.50.50.50.60.60.60.60.60.60.60.6
Percentage of Assets nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2755269626542607254625002438238923392434242123732313227822442193
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets72.871.770.772.169.962.571.173.572.376.374.777.077.575.273.870.6

us-gaap:PropertyPlantAndEquipmentNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value270626492608256325042459241923702321243024172370231322782243
Percentage of PropertyPlantAndEquipmentNet98.298.298.398.398.498.499.299.299.299.899.899.9100.0100.0100.0
Percentage of Assets71.570.569.470.868.861.570.672.971.776.274.676.977.575.273.8
Percentage of Assets nwn:NorthwestNaturalGasCompany74.473.272.574.072.064.372.875.374.077.475.776.877.475.173.7

us-gaap:PropertyPlantAndEquipmentNet us-gaap:StatementBusinessSegments

nwn:NaturalGasDistribution


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value265425972556251124542409236923192271237823642316226022262192
Percentage of PropertyPlantAndEquipmentNet96.396.396.396.396.496.497.197.197.197.797.797.697.797.797.7
Percentage of Assets70.269.168.169.467.460.269.171.370.174.572.975.275.773.572.1
Percentage of Assets nwn:NaturalGasDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value270626492608256325042459241923702321243024172370231322782243
Percentage of PropertyPlantAndEquipmentNet98.298.298.398.398.498.499.299.299.299.899.899.9100.0100.0100.0
Percentage of Assets71.570.569.470.868.861.570.672.971.776.274.676.977.575.273.8
Percentage of Assets nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:OtherNorthwestHoldings


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value4947464441401918183.8513.7883.2780.1680.1750.183
Percentage of PropertyPlantAndEquipmentNet1.81.81.71.71.61.60.80.80.80.20.20.10.00.00.0
Percentage of Assets1.31.31.21.21.11.00.60.60.60.10.10.10.00.00.0
Percentage of Assets nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:OtherNorthwestNatural


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value515151525050505050515253525151
Percentage of PropertyPlantAndEquipmentNet1.91.91.92.02.02.02.12.12.12.12.22.22.32.32.3
Percentage of Assets1.41.41.41.41.41.31.51.61.51.61.61.71.81.71.7
Percentage of Assets nwn:OtherNorthwestNatural0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value6969697070694949498.9548.9546.5630.00.00.00.0
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0
Percentage of Assets1.81.81.81.91.91.71.51.51.50.30.30.20.00.00.00.0

us-gaap:Goodwill us-gaap:BusinessAcquisition

nwn:SuncadiaTW


Goodwillus-gaap:
Period End2020-12-31
Value18
Percentage of Goodwill26.3
Percentage of Assets0.5
Percentage of Assets nwn:SuncadiaTW0.0

nwn:SuncadiaTWWater


Goodwillus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value1818191919
Percentage of Goodwill26.326.327.527.427.6
Percentage of Assets0.50.50.50.50.5
Percentage of Assets nwn:SuncadiaTWWater0.00.00.00.00.0

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value7676777878792.953.9175.0136.1630.00.00.00.0
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0
Percentage of Assets2.02.02.12.22.22.00.10.10.20.20.00.00.00.0

us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value7676777778792.763.7454.7975.9030.00.00.00.0
Percentage of OperatingLeaseRightOfUseAsset99.999.999.899.999.999.893.695.695.795.80.00.00.00.0
Percentage of Assets2.02.02.12.22.22.00.10.10.10.20.00.00.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany2.12.12.12.32.32.10.10.10.20.20.00.00.00.0

us-gaap:OperatingLeaseRightOfUseAsset us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0830.10.1180.0870.1020.1390.190.1720.2160.26
Percentage of OperatingLeaseRightOfUseAsset0.10.10.20.10.10.26.44.44.34.2
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.10.10.10.10.10.10.20.20.30.7

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value504949505147382718161412117.036.5054.192
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.31.31.31.41.41.21.10.90.60.50.40.40.40.20.20.1

us-gaap:OtherAssetsNoncurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value494848505047382717151312117.0176.505
Percentage of OtherAssetsNoncurrent98.398.198.198.598.498.999.098.597.697.397.199.299.999.8100.0
Percentage of Assets1.31.31.31.41.41.21.10.80.50.50.40.40.40.20.2
Percentage of Assets nwn:NorthwestNaturalGasCompany1.41.31.31.41.51.21.10.90.60.50.40.40.40.20.2

us-gaap:OtherAssetsNoncurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Other
Period End2020-12-312019-12-312018-12-31
Value0.2130.2450.31
Percentage of OtherAssetsNoncurrent0.40.62.2
Percentage of Assets0.00.00.0
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet0.00.00.0

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value978897837986113767610311580707711187
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.62.42.62.32.22.23.32.32.43.23.62.62.42.63.72.8

us-gaap:AccountsPayableCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value9587958277851117574102114797077110
Percentage of AccountsPayableCurrent97.299.197.198.597.698.798.598.698.099.199.299.399.499.799.4
Percentage of Assets2.52.32.52.32.12.13.32.32.33.23.52.62.32.63.6
Percentage of Assets nwn:NorthwestNaturalGasCompany2.62.42.62.42.22.23.42.42.43.33.62.62.32.63.6

us-gaap:AccountsPayableCurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Accounts
Period End2020-12-312019-12-312018-12-31
Value0.1190.6120.168
Percentage of AccountsPayableCurrent0.10.50.1
Percentage of Assets0.00.00.0
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet0.00.10.0

Accrued Income Taxes Current

us-gaap:AccruedIncomeTaxesCurrent

us-gaap:AccruedIncomeTaxesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value15231313182311137.0031111136.916121811
Percentage of AccruedIncomeTaxesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.60.40.40.50.60.30.40.20.30.30.40.20.40.60.4

us-gaap:AccruedIncomeTaxesCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value101313137.3761111126.9031010136.8871118
Percentage of AccruedIncomeTaxesCurrent66.558.999.498.839.848.897.996.798.698.899.799.799.699.799.8
Percentage of Assets0.30.40.40.40.20.30.30.40.20.30.30.40.20.40.6
Percentage of Assets nwn:NorthwestNaturalGasCompany0.30.40.40.40.20.30.40.40.20.30.30.40.20.40.6

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value572585627551486798482358307526509382297316381202
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets15.115.616.715.213.420.014.111.09.516.515.712.410.010.512.66.5

us-gaap:LiabilitiesCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value544508529437361692442325277511494375290321385
Percentage of LiabilitiesCurrent95.186.884.479.374.386.791.890.990.397.297.098.097.4101.3101.0
Percentage of Assets14.413.514.112.19.917.312.910.08.616.015.212.29.710.612.7
Percentage of Assets nwn:NorthwestNaturalGasCompany15.014.014.712.610.418.113.310.38.816.315.512.29.710.612.7

us-gaap:LiabilitiesCurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Liabilities
Period End2020-12-312019-12-312018-12-31
Value86289.366
Percentage of LiabilitiesCurrent13.75.91.8
Percentage of Assets2.30.80.3
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet8.83.21.2

Long Term Debt Current

us-gaap:LongTermDebtCurrent

us-gaap:LongTermDebtCurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value60959595350.2027594104104298474749621
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.62.52.52.61.00.02.22.93.23.30.92.82.52.53.20.7

us-gaap:LongTermDebtCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value595959590.00.074941041042984747496
Percentage of LongTermDebtCurrent99.563.062.963.00.00.099.7100.0100.099.9100.0100.0100.0100.0100.0
Percentage of Assets1.61.61.61.70.00.02.22.93.23.30.92.82.52.53.2
Percentage of Assets nwn:NorthwestNaturalGasCompany1.61.71.71.70.00.02.33.03.33.30.92.82.52.53.2

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1228000.01213000.01105000.01081000.0931000.01071000.02101000.03171000.04271000.04656000.00000
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.10.10.10.10.00.00.00.0

us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1193000.01167000.01054000.01020000.0868000.0984000.01979000.03075000.04141000.04477000.00000
Percentage of OperatingLeaseLiabilityCurrent97.196.295.494.493.291.994.297.097.096.20.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.10.10.10.10.00.00.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.10.10.10.10.00.00.00.0

us-gaap:OperatingLeaseLiabilityCurrent us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value35000.046000.051000.061000.063000.087000.0122000.096000.0130000.0179000.0
Percentage of OperatingLeaseLiabilityCurrent2.93.84.65.66.88.15.83.03.03.8
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.10.10.10.20.5

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value43485249546262393654543532393927
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.21.31.41.41.51.61.81.21.11.71.71.21.11.31.30.9

us-gaap:OtherLiabilitiesCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value434851485261613835535334313939
Percentage of OtherLiabilitiesCurrent98.799.099.297.497.597.898.096.195.997.597.396.997.0100.0100.0
Percentage of Assets1.11.31.41.31.51.51.81.21.11.71.61.11.11.31.3
Percentage of Assets nwn:NorthwestNaturalGasCompany1.21.31.41.41.51.61.81.21.11.71.71.11.11.31.3

us-gaap:OtherLiabilitiesCurrent us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Other
Period End2020-12-312019-12-312018-12-31
Value0.0490.0370.0
Percentage of OtherLiabilitiesCurrent0.10.10.0
Percentage of Assets0.00.00.0
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet0.00.00.0

Long Term Debt

us-gaap:LongTermDebt

us-gaap:LongTermDebt


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-30
Value975955955955954954881900910736736809758779779
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets25.825.425.426.426.223.825.727.728.123.122.726.325.425.725.1

us-gaap:LongTermDebt dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value917917917917917917843863873734734808758758
Percentage of LongTermDebt94.096.096.096.096.196.195.895.995.999.799.799.9100.00.0
Percentage of Assets24.224.424.425.325.222.924.626.627.023.022.626.225.425.0
Percentage of Assets nwn:NorthwestNaturalGasCompany25.225.325.526.526.324.025.427.427.823.423.026.225.425.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value915860860860918953805806806632706724683683683757
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.222.922.923.825.223.823.524.824.919.821.823.522.922.622.524.4

us-gaap:LongTermDebtNoncurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value857857857857917917769768768630704723683683683
Percentage of LongTermDebtNoncurrent93.799.699.799.699.896.195.495.495.499.799.799.9100.0100.0100.0
Percentage of Assets22.722.822.823.725.222.922.423.623.719.821.723.522.922.622.5
Percentage of Assets nwn:NorthwestNaturalGasCompany23.623.723.824.726.324.023.224.424.520.122.123.522.922.522.4

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value325328319296297300295284292293
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets8.68.78.58.28.27.58.68.89.09.2

us-gaap:DeferredIncomeTaxLiabilitiesNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value323326318307309312309298307307
Percentage of DeferredIncomeTaxLiabilitiesNet99.499.499.6103.6104.0104.1104.6104.7104.9104.8
Percentage of Assets8.68.78.58.58.57.89.09.29.59.6
Percentage of Assets nwn:NorthwestNaturalGasCompany8.99.08.88.98.98.29.39.59.89.8

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value203210217202218224228215217220221212218221223212
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.45.65.85.66.05.66.76.66.76.96.86.97.37.37.36.8

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value203210217202218224228215217220221212218221223
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.45.65.85.66.05.66.76.66.76.96.86.97.37.37.3
Percentage of Assets nwn:NorthwestNaturalGasCompany5.65.86.05.96.35.96.96.86.97.06.96.97.37.37.3

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value117118120123120119123123129120147140140137135134
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.13.23.23.43.33.03.63.84.03.84.64.64.74.54.54.3

us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value116118120122120118123123129120147140140137135
Percentage of OtherLiabilitiesNoncurrent99.499.499.699.799.899.999.999.999.999.999.999.999.999.999.9
Percentage of Assets3.13.13.23.43.33.03.63.84.03.84.64.64.74.54.4
Percentage of Assets nwn:NorthwestNaturalGasCompany3.23.33.33.53.53.13.73.94.13.84.64.54.74.54.4

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8080808080790.8410.7320.7211.4950.00.00.00.0
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0
Percentage of Assets2.12.12.12.22.22.00.00.00.00.00.00.00.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8080808080790.7720.6540.6341.4130.00.00.00.0
Percentage of OperatingLeaseLiabilityNoncurrent99.999.999.9100.0100.099.991.889.387.994.50.00.00.00.0
Percentage of Assets2.12.12.12.22.22.00.00.00.00.00.00.00.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany2.22.22.22.32.32.10.00.00.00.00.00.00.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0450.0560.0620.0240.0390.0530.0690.0780.0870.082
Percentage of OperatingLeaseLiabilityNoncurrent0.10.10.10.00.00.18.210.712.15.5
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.10.10.10.2

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6992000.06992000.06916000.06813000.06813000.06778000.0195000.02115000.02082000.02082000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.20.20.00.10.10.1

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value6986000.06986000.06849000.06761000.06761000.06726000.0143000.02013000.01980000.01980000.04812000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo99.999.999.099.299.299.273.395.295.195.10.0
Percentage of Assets0.20.20.20.20.20.20.00.10.10.10.1
Percentage of Assets nwn:NorthwestNaturalGasCompany0.20.20.20.20.20.20.00.10.10.10.2

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6000.06000.067000.052000.052000.052000.052000.0102000.0102000.0102000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo0.10.11.00.80.80.826.74.84.94.9
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.10.10.10.3

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value7156000.07156000.06986000.06867000.06866000.06866000.0129000.0154000.0129000.0129000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.20.20.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value7150000.07150000.06986000.06849000.06848000.06848000.0111000.0126000.0101000.0101000.07077000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree99.999.9100.099.799.799.786.081.878.378.30.0
Percentage of Assets0.20.20.20.20.20.20.00.00.00.00.2
Percentage of Assets nwn:NorthwestNaturalGasCompany0.20.20.20.20.20.20.00.00.00.00.2

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Lessee
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6000.06000.018000.018000.018000.018000.028000.028000.028000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree0.10.10.30.30.314.018.221.721.7
Percentage of Assets0.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.1

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value7191000.07191000.07150000.06986000.06983000.06983000.088000.093000.093000.093000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.20.20.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value7185000.07185000.07150000.06986000.06983000.06983000.088000.093000.093000.093000.07223000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour99.999.9100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.20.20.20.20.20.20.00.00.00.00.2
Percentage of Assets nwn:NorthwestNaturalGasCompany0.20.20.20.20.20.20.00.00.00.00.2

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Lessee
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6000.06000.0000000
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour0.10.10.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value7185000.07150000.07146000.07146000.089000.071000.071000.071000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value7185000.07150000.07146000.07146000.089000.071000.071000.071000.07304000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.20.20.20.20.00.00.00.00.2
Percentage of Assets nwn:NorthwestNaturalGasCompany0.20.20.20.20.00.00.00.00.2

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1231231231301301300.5260.4970.4970.497
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.33.33.33.63.63.30.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1231231231301301300.5260.4970.4970.497149
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets3.33.33.33.63.63.30.00.00.00.04.6
Percentage of Assets nwn:NorthwestNaturalGasCompany3.43.43.43.83.83.40.00.00.00.04.7

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Lessee
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0240.0240.00.00.00.00.00.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive0.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.0

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value8181818181802.9423.9034.9926.151
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.12.22.22.32.22.00.10.10.20.2

us-gaap:OperatingLeaseLiability dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value8181818180802.7513.7294.7755.89
Percentage of OperatingLeaseLiability99.999.999.999.999.999.893.595.595.795.8
Percentage of Assets2.12.22.22.32.22.00.10.10.10.2
Percentage of Assets nwn:NorthwestNaturalGasCompany2.22.32.32.42.32.10.10.10.20.2

us-gaap:OperatingLeaseLiability us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.080.1020.1130.0850.1020.140.1910.1740.2170.261
Percentage of OperatingLeaseLiability0.10.10.10.10.10.26.54.54.34.2
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.10.10.10.10.10.10.20.20.30.7

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1551571581601611613.1824.1355.2636.473
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.14.24.24.44.44.00.10.10.20.2

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1551571581601601612.9863.9575.046.204181
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue99.999.999.999.999.999.993.895.795.895.80.0
Percentage of Assets4.14.24.24.44.44.00.10.10.20.25.6
Percentage of Assets nwn:NorthwestNaturalGasCompany4.34.34.44.64.64.20.10.10.20.25.7

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0910.1070.1190.0870.1050.1440.1960.1780.2230.269
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue0.10.10.10.10.10.16.24.34.24.2
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.10.10.10.10.10.10.20.20.30.8

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue us-gaap:TypeOfArrangement

nwn:NewHeadquartersLease


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value159159159159159159160160160160
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue102.5101.3100.499.398.998.45028.33869.43040.12471.8
Percentage of Assets4.24.24.24.44.44.04.74.94.95.0
Percentage of Assets nwn:NewHeadquartersLease0.00.00.00.00.00.00.00.00.00.0

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value7475777880810.240.2320.2710.322
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.02.02.12.22.22.00.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value7475777880810.2350.2280.2650.314
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0100.0100.0100.0100.0100.097.998.397.897.5
Percentage of Assets2.02.02.12.22.22.00.00.00.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany2.02.12.12.32.32.10.00.00.00.0

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0110.0050.0060.0020.0030.0040.0050.0040.0060.008
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount0.00.00.00.00.00.02.11.72.22.5
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateNonSegment nwn:OtherNorthwestHoldings0.00.00.00.00.00.00.00.00.00.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value922936888852884901865844876794762737759772742846
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.424.923.723.624.322.525.326.027.124.923.523.925.425.524.427.3

us-gaap:StockholdersEquity dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value868881835805839857822798830746715737759772742
Percentage of StockholdersEquity94.194.294.094.595.095.194.994.694.794.093.8100.0100.0100.0100.0
Percentage of Assets23.023.522.222.323.121.424.024.625.623.422.123.925.425.524.4
Percentage of Assets nwn:NorthwestNaturalGasCompany23.924.423.223.324.122.424.825.426.423.822.423.925.425.524.4

us-gaap:StockholdersEquity us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Stockholders
Period End2020-12-312019-12-312018-12-31
Value892867761
Percentage of StockholdersEquity100.4100.299.9
Percentage of Assets23.825.323.5
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet91.296.898.8

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest


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
Value922936888852884901865844876794762737759772742850780
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.424.923.723.624.322.525.326.027.124.923.523.925.425.524.40.00.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value868881835805839857822798830746715737759772742850780
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest94.194.294.094.595.095.194.994.694.794.093.8100.0100.0100.0100.0100.0100.0
Percentage of Assets23.023.522.222.323.121.424.024.625.623.422.123.925.425.524.40.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany23.924.423.223.324.122.424.825.426.423.822.423.925.425.524.40.00.0

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

nwn:NorthwestNaturalGasCompany, nwn:NorthwestNaturalGasCompanyConsolidated


Stockholders
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value835822715742850
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest94.094.993.8100.0100.0
Percentage of Assets22.224.022.124.40.0
Percentage of Assets nwn:NorthwestNaturalGasCompany nwn:NorthwestNaturalGasCompanyConsolidated0.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, 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
Value-12.46-12.681-12.902-10.227-10.413-10.573-10.733-8.21-8.324-8.439-7.188-7.977-8.131-8.284-8.438-6.951-7.162
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-1.4-1.4-1.5-1.2-1.2-1.2-1.2-1.0-0.9-1.1-0.9-1.1-1.1-1.1-1.1-0.8-0.9
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.3-0.3-0.30.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany, us-gaap:CommonStockIncludingAdditionalPaidInCapital


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
Value319319319319319319319319319226226455452450448445383
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest34.634.136.037.536.135.436.937.836.528.529.761.859.558.360.452.349.1
Percentage of Assets8.48.58.58.88.88.09.39.89.97.17.014.815.114.914.80.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany us-gaap:CommonStockIncludingAdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany, 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
Value561574528496530548513487518528496290315330302412404
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest60.861.459.558.260.060.959.357.759.266.665.139.341.542.740.748.551.9
Percentage of Assets14.815.314.113.714.613.715.015.016.016.615.39.410.610.99.90.00.0
Percentage of Assets nwn:NorthwestNaturalGasCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value-12.46-12.681-12.902-10.227-10.413-10.573-10.733-8.21-8.324-8.439-7.188-7.977-8.131-8.284-8.438-6.951-7.162
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-1.4-1.4-1.5-1.2-1.2-1.2-1.2-1.0-0.9-1.1-0.9-1.1-1.1-1.1-1.1-0.8-0.9
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.3-0.3-0.30.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStockIncludingAdditionalPaidInCapital


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
Value569568565563562561558556555459457455452450448445383
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest61.760.763.666.163.762.264.565.963.357.960.061.859.558.360.452.349.1
Percentage of Assets15.115.115.015.615.514.016.317.117.114.414.114.815.114.914.80.00.0
Percentage of Assets us-gaap:CommonStockIncludingAdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value365380336299331351318296330342312290315330302412404
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest39.640.737.935.137.538.936.835.137.643.240.939.341.542.740.748.551.9
Percentage of Assets9.710.19.08.39.18.89.39.110.210.79.69.410.610.99.90.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value569568565563562561558556555459457455452450448447
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets15.115.115.015.615.514.016.317.117.114.414.114.815.114.914.814.4

us-gaap:CommonStockValue dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value319319319319319319319319319226226455452450448
Percentage of CommonStockValue56.156.256.556.756.856.957.257.457.649.249.5100.0100.0100.0100.0
Percentage of Assets8.48.58.58.88.88.09.39.89.97.17.014.815.114.914.8
Percentage of Assets nwn:NorthwestNaturalGasCompany8.88.88.99.29.28.49.610.110.27.27.114.815.114.814.7

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Common
Period End2020-12-312019-12-312018-12-31
Value847840739
Percentage of CommonStockValue149.9150.5161.6
Percentage of Assets22.624.522.8
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet86.693.895.9

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value365380336299331351318296330342312290315330302406
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets9.710.19.08.39.18.89.39.110.210.79.69.410.610.99.913.1

us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value561574528496530548513487518528496290315330302
Percentage of RetainedEarningsAccumulatedDeficit153.6150.9157.1165.9159.9156.3161.2164.6157.2154.3159.0100.0100.0100.0100.0
Percentage of Assets14.815.314.113.714.613.715.015.016.016.615.39.410.610.99.9
Percentage of Assets nwn:NorthwestNaturalGasCompany15.415.914.714.315.214.315.515.516.516.815.59.410.510.99.9

us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:ConsolidatedEntities

nwn:ParentCompanyCondensedBalanceSheet


Retained
Period End2020-12-312019-12-312018-12-31
Value452722
Percentage of RetainedEarningsAccumulatedDeficit13.48.57.1
Percentage of Assets1.20.80.7
Percentage of Assets nwn:ParentCompanyCondensedBalanceSheet4.63.02.9

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value-12.46-12.681-12.902-10.227-10.413-10.573-10.733-8.21-8.324-8.439-7.188-7.977-8.131-8.284-8.438-6.528-6.678-6.951
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.3-0.3-0.3-0.20.00.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-12.46-12.681-12.902-10.227-10.413-10.573-10.733-8.21-8.324-8.439-7.188-7.977-8.131-8.284-8.438
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.3-0.3-0.3
Percentage of Assets nwn:NorthwestNaturalGasCompany-0.3-0.4-0.4-0.3-0.3-0.3-0.3-0.3-0.3-0.3-0.2-0.3-0.3-0.3-0.3

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

nwn:NorthwestHoldingsandNorthwestNatural, nwn:NonQualifiedPensionPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value12-10.733-7.188-8.438-6.951
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-100.0100.0100.0100.0100.0
Percentage of Assets0.3-0.3-0.2-0.30.0
Percentage of Assets nwn:NorthwestHoldingsandNorthwestNatural nwn:NonQualifiedPensionPlansDefinedBenefit0.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value57137-5.52-11.00656102300.1825010410-4.1235810413
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax42.944.1-2.2-12.545.336.612.10.242.834.64.6-4.748.139.60.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value53136-8.494-5.0785510431-1.6725110415-4.64758104
Percentage of NetCashProvidedByUsedInOperatingActivities93.899.4153.946.198.3101.2105.7-918.7102.299.9152.1112.799.8100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax40.243.8-3.4-5.844.637.012.8-1.943.734.67.0-5.248.039.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-64008000.0-63875000.0-67512000.0-66346000.0-58990000.0-101430000.0-78491000.0-71893000.0-102340000.0-51056000.0-56378000.0-58617000.0-44970000.0-57488000.0-67600000.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-48.0-20.5-27.0-75.2-47.2-36.1-31.7-81.7-87.0-16.9-25.3-66.2-37.2-21.80.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value-60658000.0-62229000.0-75512000.0-71039000.0-55932000.0-61640000.0-75702000.0-71311000.0-45415000.0-50649000.0-57264000.0-78739000.0-44972000.0-57487000.0
Percentage of NetCashProvidedByUsedInInvestingActivities94.897.4111.8107.194.860.896.499.244.499.2101.6134.3100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-45.5-20.0-30.2-80.5-44.7-21.9-30.5-81.1-38.6-16.7-25.7-89.0-37.2-21.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value9.59-83.13267-23.779-331.7154594721100-53.5542883-15.621-39.29
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.2-26.726.9-26.9-265.4163.719.224.385.1-17.712.994.8-12.9-14.9

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.677-71.7667-17.034-311.768383432145-55.1684083-15.621-39.29
Percentage of NetCashProvidedByUsedInFinancingActivities90.586.3100.171.694.083.591.7100.245.0103.0141.5100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.5-23.126.9-19.3-249.4136.617.624.338.3-18.218.394.8-12.9-14.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value2828252524232221
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationDepletionAndAmortization dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Depreciation
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value2727252424232221
Percentage of DepreciationDepletionAndAmortization97.896.799.096.798.098.799.499.7

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-14.91-2.3294.401-1.3924.511-23.4315-3.924-12.96-14.883393.684-7.571-19.04230
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayable dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-19.225-0.7113.794-0.5170.531-22.71711-6.537-8.407-15.337363.457-7.55-18.645
Percentage of IncreaseDecreaseInAccountsPayable128.930.586.237.111.897.076.8166.664.9103.192.393.899.797.9

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value12-16.454-2.3881.0749.623-9.5712.676186.179-21.108-8.3419.9378.341-13.144-10.972
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInventories dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value12-16.588-2.3811.0919.344-9.5932.669186.174-21.097-8.7169.9388.71-13.144
Percentage of IncreaseDecreaseInInventories100.2100.899.7101.697.1100.299.7100.199.999.9104.5100.0104.4100.0

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value11-2.166-1.6054.0963.356.626-2.4281.91613-8.894-4.142.5984.953-3.9634.121
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value11-3.299-2.0954.1343.3034.593-2.5691.87513-10.639-6.9074.3785.953-3.963
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet104.1152.3130.5100.998.669.3105.897.999.6119.6166.8168.5120.2100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value57137-5.52-11.00656102300.1825010410-4.1235810413
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax42.944.1-2.2-12.545.336.612.10.242.834.64.6-4.748.139.60.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value53136-8.494-5.0785510431-1.6725110415-4.64758104
Percentage of NetCashProvidedByUsedInOperatingActivities93.899.4153.946.198.3101.2105.7-918.7102.299.9152.1112.799.8100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax40.243.8-3.4-5.844.637.012.8-1.943.734.67.0-5.248.039.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.7245952-17.912-4.8524736-19.3011.0954335-11.794-0.99841-90.167-8.4952.72940
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.519.120.8-20.3-3.916.914.8-21.90.914.316.1-13.3-0.815.70.00.00.00.0

us-gaap:NetIncomeLoss dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value0.5896046-20.22-4.7124939-17.5883.0544337-11.794-0.99841-90.167-8.4952.72940
Percentage of NetIncomeLoss-81.4101.089.0112.997.1103.5107.891.1278.9101.6104.9100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.419.318.5-22.9-3.817.516.0-20.02.614.516.9-13.3-0.815.70.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

nwn:NorthwestNaturalGasCompany, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.58960-20.22-4.71249-17.5883.05443-11.794-0.99841
Percentage of NetIncomeLoss-81.4101.0112.997.1103.591.1278.9101.6100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.419.3-22.9-3.817.5-20.02.614.5-13.3-0.815.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-0.72459-17.912-4.85247-19.3011.09543-11.794-0.99841
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.519.1-20.3-3.916.9-21.90.914.3-13.3-0.815.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-64008000.0-63875000.0-67512000.0-66346000.0-58990000.0-101430000.0-78491000.0-71893000.0-102340000.0-51056000.0-56378000.0-58617000.0-44970000.0-57488000.0-67600000.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-48.0-20.5-27.0-75.2-47.2-36.1-31.7-81.7-87.0-16.9-25.3-66.2-37.2-21.80.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value-60658000.0-62229000.0-75512000.0-71039000.0-55932000.0-61640000.0-75702000.0-71311000.0-45415000.0-50649000.0-57264000.0-78739000.0-44972000.0-57487000.0
Percentage of NetCashProvidedByUsedInInvestingActivities94.897.4111.8107.194.860.896.499.244.499.2101.6134.3100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-45.5-20.0-30.2-80.5-44.7-21.9-30.5-81.1-38.6-16.7-25.7-89.0-37.2-21.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidatedEntities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

srt:ParentCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6465797164577061424855564557
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3.3371.6042.1850.7282.8431.2121.0130.6060.3660.1060.3080.00.00.0
Percentage of PaymentsToAcquirePropertyPlantAndEquipment5.22.42.71.04.42.11.41.00.90.20.60.00.00.0

us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.6930.1060.561.1130.5210.0770.6990.6440.1050.052-0.1810.5111.240.435
Percentage of PaymentsToAcquirePropertyPlantAndEquipment1.10.20.71.60.80.11.01.00.20.1-0.30.92.80.8

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6063766961566860414855554356
Percentage of PaymentsToAcquirePropertyPlantAndEquipment93.797.496.697.494.897.897.698.098.999.799.899.197.299.2

us-gaap:OperatingSegments, nwn:NorthwestNaturalGasCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6164777061566961424855564557
Percentage of PaymentsToAcquirePropertyPlantAndEquipment94.897.697.399.095.697.998.699.099.199.899.4100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value9.59-83.13267-23.779-331.7154594721100-53.5542883-15.621-39.29
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.2-26.726.9-26.9-265.4163.719.224.385.1-17.712.994.8-12.9-14.9

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.677-71.7667-17.034-311.768383432145-55.1684083-15.621-39.29
Percentage of NetCashProvidedByUsedInFinancingActivities90.586.3100.171.694.083.591.7100.245.0103.0141.5100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.5-23.126.9-19.3-249.4136.617.624.338.3-18.218.394.8-12.9-14.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax nwn:NorthwestNaturalGasCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:ProceedsFromIssuanceOfLongTermDebt


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value0.00.00.01500.00.01750.00.0500.0
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.00.0100.00.00.0100.00.00.0100.00.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.00.00.01500.00.01400.00.050
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.00.0100.00.00.080.00.00.0100.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value0.00.00.0752010.00.00.0750.00.0220.0
Percentage of RepaymentsOfLongTermDebt0.00.00.0100.0100.0100.00.00.0100.00.00.0100.00.0

us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Repayments
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
Value0.00.00.0752010.00.00.0750.00.022
Percentage of RepaymentsOfLongTermDebt0.00.00.0100.0100.0100.00.00.0100.00.00.0100.0

Payments Of Dividends Common Stock

us-gaap:PaymentsOfDividendsCommonStock

us-gaap:PaymentsOfDividendsCommonStock


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value131313131313131312121212121213
Percentage of PaymentsOfDividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfDividendsCommonStock dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value131313131313131312120.0121212
Percentage of PaymentsOfDividendsCommonStock100.0100.7100.0100.099.899.7100.3100.0100.0100.00.0100.0100.0100.0

Debt Instrument Interest Rate Stated Percentage

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

us-gaap:DebtInstrumentInterestRateStatedPercentage

nwn:NorthwestNaturalGasCompany, nwn:Note2822SeriesDue2027


Debt
Period End2020-12-312019-12-312018-12-31
Value2.8220.02820.0282
Percentage of DebtInstrumentInterestRateStatedPercentage100.0100.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note2822SeriesDue20270.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note3141SeriesDue2029


Debt
Period End2020-12-312019-12-312019-09-302019-06-30
Value3.1410.03140.031410.03141
Percentage of DebtInstrumentInterestRateStatedPercentage111.3111.30.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3141SeriesDue20290.00.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note3176SeriesDue2021


Debt
Period End2020-12-312019-12-312018-12-31
Value3.1760.03180.0318
Percentage of DebtInstrumentInterestRateStatedPercentage112.5112.8112.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3176SeriesDue20210.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note3211SeriesDue2026


Debt
Period End2020-12-312019-12-312018-12-31
Value3.2110.03210.0321
Percentage of DebtInstrumentInterestRateStatedPercentage113.8113.8113.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3211SeriesDue20260.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note3542SeriesDue2023


Debt
Period End2020-12-312019-12-312018-12-31
Value3.5420.03540.0354
Percentage of DebtInstrumentInterestRateStatedPercentage125.5125.5125.5
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3542SeriesDue20230.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note3600SeriesDue2050


Debt
Period End2020-12-31
Value3.6
Percentage of DebtInstrumentInterestRateStatedPercentage127.6
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3600SeriesDue20500.0

nwn:NorthwestNaturalGasCompany, nwn:Note3685SeriesDue2047


Debt
Period End2020-12-312019-12-312018-12-31
Value3.6850.03690.0369
Percentage of DebtInstrumentInterestRateStatedPercentage130.6130.9130.9
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3685SeriesDue20470.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note3869SeriesDue2049


Debt
Period End2020-12-312019-12-312019-09-302019-06-30
Value3.8690.03870.038690.03869
Percentage of DebtInstrumentInterestRateStatedPercentage137.1137.20.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note3869SeriesDue20490.00.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note4000SeriesDue2042


Debt
Period End2020-12-312019-12-312018-12-31
Value4.00.040.04
Percentage of DebtInstrumentInterestRateStatedPercentage141.7141.8141.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note4000SeriesDue20420.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note4110SeriesDue2048


Debt
Period End2020-12-312019-12-312018-12-31
Value4.110.04110.0411
Percentage of DebtInstrumentInterestRateStatedPercentage145.6145.7145.7
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note4110SeriesDue20480.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note4136SeriesDue2046


Debt
Period End2020-12-312019-12-312018-12-31
Value4.1360.04140.0414
Percentage of DebtInstrumentInterestRateStatedPercentage146.6146.8146.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note4136SeriesDue20460.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note5250SeriesDue2035


Debt
Period End2020-12-312019-12-312018-12-31
Value5.250.05250.0525
Percentage of DebtInstrumentInterestRateStatedPercentage186.0186.2186.2
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note5250SeriesDue20350.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note5370SeriesDue2020


Debt
Period End2020-12-312019-12-312018-12-31
Value5.370.05370.0537
Percentage of DebtInstrumentInterestRateStatedPercentage190.3190.4190.4
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note5370SeriesDue20200.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note537SeriesDue2020


Debt
Period End2020-09-302020-06-302020-03-31
Value5.370.05370.0537
Percentage of DebtInstrumentInterestRateStatedPercentage0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note537SeriesDue20200.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note5620SeriesDue2023


Debt
Period End2020-12-312019-12-312018-12-31
Value5.620.05620.0562
Percentage of DebtInstrumentInterestRateStatedPercentage199.1199.3199.3
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note5620SeriesDue20230.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note5660SeriesDue2033


Debt
Period End2020-12-312019-12-312018-12-31
Value5.660.05660.0566
Percentage of DebtInstrumentInterestRateStatedPercentage200.6200.7200.7
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note5660SeriesDue20330.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note5820SeriesDue2032


Debt
Period End2020-12-312019-12-312018-12-31
Value5.820.05820.0582
Percentage of DebtInstrumentInterestRateStatedPercentage206.2206.4206.4
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note5820SeriesDue20320.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note6520SeriesDue2025


Debt
Period End2020-12-312019-12-312018-12-31
Value6.520.06520.0652
Percentage of DebtInstrumentInterestRateStatedPercentage231.0231.2231.2
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note6520SeriesDue20250.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note6650SeriesDue2027


Debt
Period End2020-12-312019-12-312018-12-31
Value6.650.06650.0665
Percentage of DebtInstrumentInterestRateStatedPercentage235.6235.8235.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note6650SeriesDue20270.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note6650SeriesDue2028


Debt
Period End2020-12-312019-12-312018-12-31
Value6.650.06650.0665
Percentage of DebtInstrumentInterestRateStatedPercentage235.6235.8235.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note6650SeriesDue20280.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note7000SeriesDue2027


Debt
Period End2020-12-312019-12-312018-12-31
Value7.00.070.07
Percentage of DebtInstrumentInterestRateStatedPercentage248.1248.2248.2
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note7000SeriesDue20270.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note7050SeriesDue2026


Debt
Period End2020-12-312019-12-312018-12-31
Value7.050.07050.0705
Percentage of DebtInstrumentInterestRateStatedPercentage249.8250.0250.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note7050SeriesDue20260.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note7720SeriesDue2025


Debt
Period End2020-12-312019-12-312018-12-31
Value7.720.07720.0772
Percentage of DebtInstrumentInterestRateStatedPercentage273.6273.8273.8
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note7720SeriesDue20250.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note7740SeriesDue2030


Debt
Period End2020-12-312019-12-312018-12-31
Value7.740.07740.0774
Percentage of DebtInstrumentInterestRateStatedPercentage274.3274.5274.5
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note7740SeriesDue20300.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note7850SeriesDue2030


Debt
Period End2020-12-312019-12-312018-12-31
Value7.850.07850.0785
Percentage of DebtInstrumentInterestRateStatedPercentage278.2278.4278.4
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note7850SeriesDue20300.00.00.0

nwn:NorthwestNaturalGasCompany, nwn:Note9050SeriesDue2021


Debt
Period End2020-12-312019-12-312018-12-31
Value9.050.09050.0905
Percentage of DebtInstrumentInterestRateStatedPercentage320.7320.9320.9
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:NorthwestNaturalGasCompany nwn:Note9050SeriesDue20210.00.00.0

us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:ConsolidationItems, us-gaap:DebtInstrument, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:NWNWaterTermLoanDue2021, nwn:OtherNorthwestHoldings


Debt
Period End2020-12-312019-12-31
Value0.70.0235
Percentage of DebtInstrumentInterestRateStatedPercentage24.883.3
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations us-gaap:CorporateNonSegment nwn:NWNWaterTermLoanDue2021 nwn:OtherNorthwestHoldings0.00.0

us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:DebtInstrument

nwn:FiveYearTermLoanDue2026


Debt
Period End2021-06-30
Value0.9
Percentage of DebtInstrumentInterestRateStatedPercentage0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:FiveYearTermLoanDue20260.0

nwn:TwoyearTermLoanDue2021


Debt
Period End2021-03-312020-09-302020-06-302020-03-312019-09-302019-06-30
Value0.660.740.00730.01820.02650.0286
Percentage of DebtInstrumentInterestRateStatedPercentage0.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations nwn:TwoyearTermLoanDue20210.00.00.00.00.00.0

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:EffectiveIncomeTaxRateContinuingOperations


Effective
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value27.725.622.30.2460.2280.0070.190.2340.167-0.0040.2780.3150.271-0.0310.42
Percentage of EffectiveIncomeTaxRateContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateContinuingOperations dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Effective
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value32.825.523.10.2310.2280.0040.1860.2440.168-0.0040.2780.3210.271
Percentage of EffectiveIncomeTaxRateContinuingOperations118.499.6103.693.9100.057.197.9104.3100.6100.0100.0101.9100.0

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber

nwn:RestatedStockOption


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value9438.010938.055938.091688.0180160.0352690.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber100.0100.0100.0100.0100.0100.0

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

nwn:RestatedStockOption


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value45.7445.6744.9644.4344.3844.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice100.0100.0100.0100.0100.0100.0

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:AwardType, us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

us-gaap:RestrictedStockUnitsRSU, nwn:LongTermIncentivePlan


Share
Period End2021-06-302021-03-312020-12-31
Value-404.038160.0168.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod100.0100.0100.0

Deferred Tax Liabilities

us-gaap:DeferredTaxLiabilities

us-gaap:DeferredTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-31
Value319295280270
Percentage of DeferredTaxLiabilities100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-31
Value318309294287
Percentage of DeferredTaxLiabilities99.6104.6105.1106.2

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-31
Value80575756
Percentage of DeferredTaxAssetsNet100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-31
Value75545756
Percentage of DeferredTaxAssetsNet92.995.0100.0100.0

Proceeds From Repayments Of Short Term Debt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt


Proceeds
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-1.231-317.02508345-156.311-41.22911653-2.9-4.254
Percentage of ProceedsFromRepaymentsOfShortTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromRepaymentsOfShortTermDebt dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Proceeds
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
Value1743-297.01747945-176.3-41.211753-2.9-4.2
Percentage of ProceedsFromRepaymentsOfShortTermDebt-1483.3137.993.769.795.3100.0112.899.9100.0100.0100.0100.0

nwn:AdditionalRatePerTherm us-gaap:MajorCustomers

nwn:AdditionalRatePerTherm

nwn:JonahEnergyLLC


Additional
Period End2021-06-302021-03-31
Value00.4725
Percentage of AdditionalRatePerTherm0.0100.0

nwn:AmortizationofRegulatoryBalancingAccount us-gaap:RetirementPlanType

nwn:AmortizationofRegulatoryBalancingAccount

us-gaap:PensionPlansDefinedBenefit


Amortizationof
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1.2812.8010.6751.2812.8010.6751.281120.00.00.0
Percentage of AmortizationofRegulatoryBalancingAccount100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

nwn:AnnualInsuranceProceedstoApplyAgainstRemediationCosts

nwn:AnnualInsuranceProceedstoApplyAgainstRemediationCosts


Annual
Period End2021-06-302021-03-31
Value05000000.0
Percentage of AnnualInsuranceProceedstoApplyAgainstRemediationCosts0.0100.0

nwn:AnnualTariffRiderCollection

nwn:AnnualTariffRiderCollection


Annual
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value05000000.0005000000.0005000000.0
Percentage of AnnualTariffRiderCollection0.0100.00.00.0100.00.00.0100.0

nwn:ChangeInDecouplingRegulatoryDeferral

nwn:ChangeInDecouplingRegulatoryDeferral


Change
Period End2021-06-302021-03-312020-06-302020-03-31
Value7516000.0-656000.01856000.0-6137000.0
Percentage of ChangeInDecouplingRegulatoryDeferral100.0100.0100.0100.0

nwn:ChangeInDecouplingRegulatoryDeferral dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Change
Period End2021-06-302021-03-312020-06-302020-03-31
Value6204000.0656000.0-10418000.06137000.0
Percentage of ChangeInDecouplingRegulatoryDeferral82.5-100.0-561.3-100.0

nwn:CostIncurredStudiesandDesignCosts us-gaap:EnvironmentalRemediationSite

nwn:CostIncurredStudiesandDesignCosts

nwn:FrontStreet


Cost
Period End2021-06-302021-03-31
Value-200000.02400000.0
Percentage of CostIncurredStudiesandDesignCosts100.0100.0

nwn:DebtInstrumentCovenantConsolidatedIndebtednesstoCapitalizationRatio us-gaap:DebtInstrument

nwn:DebtInstrumentCovenantConsolidatedIndebtednesstoCapitalizationRatio

nwn:TwoyearTermLoanDue2021


Debt
Period End2021-06-302021-03-31
Value070.0
Percentage of DebtInstrumentCovenantConsolidatedIndebtednesstoCapitalizationRatio0.0100.0

nwn:DefinedBenefitPlanAmountAllocatedToConstruction us-gaap:RetirementPlanType

nwn:DefinedBenefitPlanAmountAllocatedToConstruction

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value22000.021000.025000.023000.023000.025000.023000.024000.027000.028000.027000.0136000.0
Percentage of DefinedBenefitPlanAmountAllocatedToConstruction100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value743000.0726000.0695000.0680000.0668000.0608000.0596000.0586000.0659000.0685000.0682000.01581000.0
Percentage of DefinedBenefitPlanAmountAllocatedToConstruction3377.33457.12780.02956.52904.32432.02591.32441.72440.72446.42525.91162.5

nwn:DefinedBenefitPlanNetAmountChargedToExpense us-gaap:RetirementPlanType

nwn:DefinedBenefitPlanNetAmountChargedToExpense

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value0.2130.2130.3250.2890.290.3030.3060.3050.2870.2870.2870.257
Percentage of DefinedBenefitPlanNetAmountChargedToExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value4.9956.5345.4485.5527.0834.6435.26272.0741.9421.9351.876
Percentage of DefinedBenefitPlanNetAmountChargedToExpense2345.13067.61676.31921.12442.41532.31719.08853.1722.6676.7674.2730.0

nwn:DefinedBenefitPlanNetPeriodicBenefitCostChargedToExpense us-gaap:RetirementPlanType

nwn:DefinedBenefitPlanNetPeriodicBenefitCostChargedToExpense

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.2130.2130.3250.2890.290.3030.3060.3050.2870.2870.287
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostChargedToExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value3.7143.7334.7734.2714.2823.9683.9793.9912.0741.9421.935
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostChargedToExpense1743.71752.61468.61477.91476.61309.61300.31308.5722.6676.7674.2

nwn:ExciseTaxes

nwn:ExciseTaxes


Excise
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value5.671123.5554.454113.5344.49611
Percentage of ExciseTaxes100.0100.0100.0100.0100.0100.0100.0100.0

nwn:ExciseTaxes dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Excise
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value5.65123.5554.454113.5344.49611
Percentage of ExciseTaxes99.699.9100.0100.0100.0100.0100.0100.0

nwn:OtherTaxExpenseBenefitdifferencestobeflowedthroughbyregulatorycommissions

nwn:OtherTaxExpenseBenefitdifferencestobeflowedthroughbyregulatorycommissions


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value21000.0-3605000.01051000.0173000.0-2525000.02090000.0-37000.0-5260000.0-266000.0-14000.0
Percentage of OtherTaxExpenseBenefitdifferencestobeflowedthroughbyregulatorycommissions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:OtherTaxExpenseBenefitdifferencestobeflowedthroughbyregulatorycommissions dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value21000.0-3605000.01051000.0173000.0-2525000.02090000.0-37000.0-5260000.0-266000.0-14000.0
Percentage of OtherTaxExpenseBenefitdifferencestobeflowedthroughbyregulatorycommissions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:RepaymentsOfCommercialPaperMaturitiesGreaterThan90Days

nwn:RepaymentsOfCommercialPaperMaturitiesGreaterThan90Days


Repayments
Period End2021-06-302021-03-31
Value-95025000.0-100000000.0
Percentage of RepaymentsOfCommercialPaperMaturitiesGreaterThan90Days100.0100.0

nwn:RepaymentsOfCommercialPaperMaturitiesGreaterThan90Days dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Repayments
Period End2021-06-302021-03-31
Value-95025000.0-100000000.0
Percentage of RepaymentsOfCommercialPaperMaturitiesGreaterThan90Days100.0100.0

nwn:StockIssuedDuringPeriodValueEquityBasedPlanNetofSharesWithheldforTaxes us-gaap:StatementEquityComponents

nwn:StockIssuedDuringPeriodValueEquityBasedPlanNetofSharesWithheldforTaxes

us-gaap:CommonStockIncludingAdditionalPaidInCapital


Stock
Period End2021-06-302020-06-30
Value1303000.01248000.0
Percentage of StockIssuedDuringPeriodValueEquityBasedPlanNetofSharesWithheldforTaxes100.0100.0

nwn:TotalAnnualRemediationExpenseandInterest

nwn:TotalAnnualRemediationExpenseandInterest


Total
Period End2021-06-302021-03-31
Value010000000.0
Percentage of TotalAnnualRemediationExpenseandInterest0.0100.0

nwn:TotalExpensesDiscontinuedOperations us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

nwn:TotalExpensesDiscontinuedOperations

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Total
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
Value1.872.5432.9911.9642.6082.4913.0462.0152.0361.6311.9011.721
Percentage of TotalExpensesDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts

us-gaap:CommonStockIncludingAdditionalPaidInCapital


Adjustments
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value006000.0-4000.0-92952000.00
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts0.00.0100.0100.0100.00.0

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value422000.0593000.02489000.0-498000.0538000.0694000.0
Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease us-gaap:EquitySecuritiesByIndustry

nwn:Accruedunbilledandother


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value022000.0109000.025000.030000.02000.0
Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease0.03.74.4-5.05.60.3

nwn:Commercial


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-62000.0-171000.0676000.0-204000.0129000.0220000.0
Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease-14.7-28.827.241.024.031.7

nwn:Industrial


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-9000.0-59000.051000.0-8000.07000.027000.0
Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease-2.1-9.92.01.61.33.9

nwn:Residential


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value493000.0801000.01653000.0-311000.0372000.0445000.0
Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease116.8135.166.462.469.164.1

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries


Allowance
Period End2021-06-302021-03-312020-03-31
Value642000.0309000.038000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries us-gaap:EquitySecuritiesByIndustry

nwn:Accruedunbilledandother


Allowance
Period End2021-06-302021-03-312020-03-31
Value42000.012000.03000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries6.53.97.9

nwn:Commercial


Allowance
Period End2021-06-302021-03-312020-03-31
Value121000.0144000.034000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries18.846.689.5

nwn:Residential


Allowance
Period End2021-06-302021-03-312020-03-31
Value481000.0156000.00
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries74.950.50.0

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs


Allowance
Period End2020-12-312020-09-302020-06-302020-03-31
Value298000.066000.0307000.06000.0
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs us-gaap:EquitySecuritiesByIndustry

nwn:Commercial


Allowance
Period End2020-12-312020-09-302020-06-302020-03-31
Value-86000.0191000.069000.00
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs-28.9289.422.50.0

nwn:Industrial


Allowance
Period End2021-06-302021-03-312020-06-302020-03-31
Value2000.03000.06000.00
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs0.00.02.00.0

nwn:Residential


Allowance
Period End2020-12-312020-09-302020-06-302020-03-31
Value259000.0-57000.0230000.06000.0
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs86.9-86.474.9100.0

us-gaap:AmortizationOfRegulatoryAsset

us-gaap:AmortizationOfRegulatoryAsset


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value3.9633.6344.0685.1444.484.0874.6985.0074.6874.784.6284.243.7434.0734.317
Percentage of AmortizationOfRegulatoryAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmortizationOfRegulatoryAsset dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value3.9633.6344.0685.1444.484.0874.6985.0074.6874.784.6284.243.7434.073
Percentage of AmortizationOfRegulatoryAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:BusinessCombinationConsiderationTransferred1 us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationConsiderationTransferred1

nwn:Otherinsignificantacquisitions


Business
Period End2021-03-312020-12-312020-09-302020-06-302019-12-312019-09-30
Value1.50.00.00.20.60.7
Percentage of BusinessCombinationConsiderationTransferred1100.00.00.0100.0100.0100.0

nwn:SuncadiaTWWater


Business
Period End2020-12-312020-09-302020-06-302020-03-31
Value0.00.00.038
Percentage of BusinessCombinationConsiderationTransferred10.00.00.00.0

us-gaap:BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual

nwn:Sunriver


Business
Period End2020-09-30
Value600000.0
Percentage of BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual100.0

us-gaap:BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual

nwn:Sunriver


Business
Period End2020-09-302020-06-302019-12-312019-09-30
Value1900000.01500000.04300000.01700000.0
Percentage of BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value2.798-9.942-5.758-101.131-334.022461-0.874-50.363480.184
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1.6912.284-16.68-93.151-311.971426-0.355-51.5951-1.114
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect60.4-23.0289.792.193.492.440.6102.4106.2-605.4

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations


Cash
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-2136000.0-1441000.0-152000.0-694000.0-1179000.0402000.0-749000.0-301000.01192000.0-336000.0-182000.0-101000.0-103000.0
Percentage of CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations


Cash
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value1.1881.253-0.171-0.3760.967-0.8931.377-0.739-1.8610.516-0.4561.156192
Percentage of CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockDividendsPerShareCashPaid

us-gaap:CommonStockDividendsPerShareCashPaid


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.480.480.47750.47750.47750.47750.4750.4750.4750.4750.47250.47250.47250.4725
Percentage of CommonStockDividendsPerShareCashPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxesAndTaxCredits

us-gaap:DeferredIncomeTaxesAndTaxCredits


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-2.0973.145191.6141.418-3.4223.846-3.446-0.3896.30610-7.273-2.113-69.701
Percentage of DeferredIncomeTaxesAndTaxCredits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxesAndTaxCredits dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-2.3912.5927.0520.3591.131-3.8974.051-5.047-1.036.0729.981-7.038-3.47512
Percentage of DeferredIncomeTaxesAndTaxCredits114.082.437.022.279.8113.9105.3146.5264.896.396.096.8165.596.5

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value-0.131-0.131-0.173-0.142-0.143-0.097-0.096-0.097-0.11-0.112-0.11-0.138
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value-5.5-5.501-5.082-4.778-4.778-3.604-3.603-3.603-5.65-4.524-4.523-3.656
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses4198.54199.22937.63364.83341.33715.53753.13714.45136.44039.34111.82649.3

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value-117000.0-117000.0-119000.0-117000.0-117000.0-117000.0-117000.0-117000.0-117000.0-117000.0-117000.0-117000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value6.0996.0995.3585.4965.4965.2075.2075.2075.1435.155.1515.112
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanInterestCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value0.1650.1650.2290.2230.2230.2810.2830.2810.2410.2410.2410.274
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value3.3423.3434.0714.0114.0114.6624.6614.6624.3364.1834.1834.484
Percentage of DefinedBenefitPlanInterestCost2025.52026.11777.71798.71798.71659.11647.01659.11799.21735.71735.71636.5

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value0.2350.2340.350.3120.3130.3280.3290.3290.3140.3150.3140.393
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value4.4574.4595.4684.9514.954.5764.5754.5776.6115.3745.3734.941
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost1896.61905.61562.31586.91581.51395.11390.61391.22105.41706.01711.11257.3

us-gaap:DefinedBenefitPlanServiceCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value56000.055000.067000.064000.064000.067000.067000.068000.080000.079000.080000.098000.0
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value1714000.01714000.01673000.01658000.01657000.01516000.01516000.01517000.01757000.01807000.01807000.01881000.0
Percentage of DefinedBenefitPlanServiceCost3060.73116.42497.02590.62589.12262.72262.72230.92196.22287.32258.81919.4

us-gaap:DefinedContributionPlanCostRecognized

us-gaap:DefinedContributionPlanCostRecognized


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2100000.02600000.01800000.01900000.02500000.01500000.01700000.02100000.01500000.01500000.02000000.0
Percentage of DefinedContributionPlanCostRecognized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortization

us-gaap:DepreciationAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value28282725252424232221212121202020
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortization dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2727262524242323222121212120
Percentage of DepreciationAndAmortization97.896.798.199.096.798.097.698.799.499.799.799.999.7100.0

us-gaap:DepreciationAndAmortization us-gaap:ConsolidatedEntities

srt:ParentCompany


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2828272525242423222121212120
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortization us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.6140.9280.5090.2530.850.4850.5780.3010.1440.0680.0750.0310.0570.007
Percentage of DepreciationAndAmortization2.23.31.91.03.32.02.41.30.60.30.30.10.30.0

us-gaap:CorporateNonSegment, nwn:OtherNorthwestNatural


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.2570.2560.2550.2480.2480.2440.240.2440.2510.2550.2780.3270.3240.325
Percentage of DepreciationAndAmortization0.90.90.91.01.01.01.01.01.11.21.31.51.51.6

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2726262524232322212121212020
Percentage of DepreciationAndAmortization96.995.897.298.195.897.096.697.798.298.598.498.398.298.4

us-gaap:OperatingSegments, nwn:NorthwestNaturalGasCompany


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2727262524242323222121212120
Percentage of DepreciationAndAmortization97.896.798.199.096.798.097.698.799.499.799.799.999.7100.0

us-gaap:DerivativeGainOnDerivative

us-gaap:DerivativeGainOnDerivative


Derivative
Period End2021-06-302021-03-31
Value4.25.1
Percentage of DerivativeGainOnDerivative100.0100.0

us-gaap:DerivativeLossOnDerivative us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeLossOnDerivative

nwn:Financial


Derivative
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302018-09-302018-06-30
Value0.01.12.11.10.91.94.7
Percentage of DerivativeLossOnDerivative0.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Discontinued
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
Value457000.01041000.0383000.0-1056000.0-2186000.0-1081000.0-1298000.0-294000.0-1288000.0-883000.0-895000.0-644000.0-194440000.0-1005000.0
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare


Discontinued
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.20.020.01-0.02-0.05-0.02-0.03-0.01-0.03-0.02-0.02-0.02-4.34-0.02-0.04-0.04
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Discontinued
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
Value0.20.020.01-0.02-0.05-0.02-0.03-0.01-0.04-0.02-0.02-0.02
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0133.3100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare


Discontinued
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.20.020.01-0.02-0.05-0.02-0.03-0.01-0.03-0.02-0.02-0.02-4.33-0.02-0.04-0.04
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Discontinued
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
Value0.20.020.01-0.02-0.05-0.02-0.03-0.01-0.03-0.02-0.02-0.02
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Discontinued
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
Value2.2430.2760.103-0.278-0.578-0.286-0.342-0.077-0.329-0.233-0.236-0.17-69.782-0.397
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Disposal
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
Value74000.0105000.0106000.0106000.0106000.0105000.0106000.0106000.0106000.0106000.0108000.0110000.01131000.01131000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Disposal
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
Value37000.061000.053000.047000.060000.040000.060000.059000.060000.0-261000.0346000.0334000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationOperatingExpense

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Disposal
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
Value1599000.02148000.02604000.01580000.02210000.02113000.02651000.01613000.01632000.01549000.01554000.01036000.02076000.01248000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOperatingExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherExpense us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherExpense

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Disposal
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
Value160000.0229000.0228000.0231000.0232000.0233000.0229000.0237000.0-181000.0237000.0-107000.0241000.0-824000.0603000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Disposal
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
Value2.3273.5843.3740.9080.4221.411.7481.7210.7480.7481.0061.0771.7971.977
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:DividendsCommonStockCash

nwn:NorthwestNaturalGasCompany, us-gaap:RetainedEarnings


Dividends
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value131313131313131312120.0131313
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

us-gaap:DividendsCommonStockCash us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Dividends
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1415141414141414131413131313
Percentage of DividendsCommonStockCash105.2108.2105.5105.5105.3108.0105.6105.7106.4108.30.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate


Effective
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value20.7900.21000.210.140.21
Percentage of EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate100.00.0100.00.00.0100.0100.0100.0

us-gaap:EnvironmentalExitCostsAnticipatedCost us-gaap:Range, us-gaap:EnvironmentalRemediationSite

us-gaap:EnvironmentalExitCostsAnticipatedCost

srt:Maximum, nwn:GascoSiltronicSediments


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302012-05-31
Value0.03500.00.0350
Percentage of EnvironmentalExitCostsAnticipatedCost0.0100.00.00.0100.0

srt:Minimum, nwn:GascoSiltronicSediments


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302012-05-31
Value-1.149-0.5-0.649
Percentage of EnvironmentalExitCostsAnticipatedCost0.014.10.00.014.0

us-gaap:EnvironmentalRemediationExpense

us-gaap:EnvironmentalRemediationExpense


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1.5093.7773.1970.8671.6224.0055.0790.967-2.6568.9473.5991.0221.8824.6244.3711.355
Percentage of EnvironmentalRemediationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnvironmentalRemediationExpense dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.5093.7773.1970.8671.6224.0055.0790.967-2.6568.9473.5991.0221.8824.624
Percentage of EnvironmentalRemediationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EnvironmentalRemediationExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.5093.7773.1970.8671.6224.0055.0790.967-2.6568.9473.5991.0221.8824.624
Percentage of EnvironmentalRemediationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeasePrincipalPayments

us-gaap:FinanceLeasePrincipalPayments


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value134000.0544000.0163000.0215000.0302000.0155000.000
Percentage of FinanceLeasePrincipalPayments100.0100.0100.0100.0100.0100.00.00.0

us-gaap:FinanceLeasePrincipalPayments dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value134000.0544000.0163000.0215000.0302000.0155000.000
Percentage of FinanceLeasePrincipalPayments100.0100.0100.0100.0100.0100.00.00.0

us-gaap:GainLossOnDerivativeInstrumentsNetPretax dei:LegalEntity, us-gaap:DerivativeInstrumentRisk

us-gaap:GainLossOnDerivativeInstrumentsNetPretax

nwn:NorthwestHoldingsandNorthwestNatural, us-gaap:CommodityContract


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.0-0.004-0.0280.0960.127-0.371-0.0880.291-0.6290.3450.253-0.0980.134-0.079
Percentage of GainLossOnDerivativeInstrumentsNetPretax0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GainLossOnDerivativeInstrumentsNetPretax dei:LegalEntity, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

nwn:NorthwestHoldingsandNorthwestNatural, us-gaap:CommodityContract, us-gaap:CostOfSales


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1620-20.929285.492-5.3435.6082.391-5.1437.0070.145-4.473-2.6585.747
Percentage of GainLossOnDerivativeInstrumentsNetPretax0.0-512050.074746.429293.84324.41440.2-6372.7821.6817.62031.057.34564.3-1983.6-7274.7

nwn:NorthwestHoldingsandNorthwestNatural, us-gaap:CommodityContract, us-gaap:Sales


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.0-0.027-0.1910.6580.754-2.433-0.6042.002-4.3332.3671.782-0.2860.391-0.227
Percentage of GainLossOnDerivativeInstrumentsNetPretax0.0675.0682.1685.4593.7655.8686.4688.0688.9686.1704.3291.8291.8287.3

nwn:NorthwestHoldingsandNorthwestNatural, us-gaap:ForeignExchangeContract, us-gaap:CostOfSales


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.0450.0770.1830.1360.459-0.4660.078-0.1330.246-0.089-0.2840.21-0.056-0.154
Percentage of GainLossOnDerivativeInstrumentsNetPretax0.0-1925.0-653.6141.7361.4125.6-88.6-45.7-39.1-25.8-112.3-214.3-41.8194.9

us-gaap:GainLossOnDerivativeInstrumentsNetPretax dei:LegalEntity, us-gaap:DerivativeInstrumentRisk, us-gaap:RegulatoryAsset

nwn:NorthwestHoldingsandNorthwestNatural, us-gaap:CommodityContract, us-gaap:DeferredDerivativeGainLoss


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-16.323-20.45921-28.684-6.1197.405-5.092-4.1028.847-9.0291.094-4.285-2.9155.895
Percentage of GainLossOnDerivativeInstrumentsNetPretax0.0511475.0-75328.6-29879.2-4818.1-1996.05786.4-1409.6-1406.5-2617.1432.44372.4-2175.4-7462.0

nwn:NorthwestHoldingsandNorthwestNatural, us-gaap:ForeignExchangeContract, us-gaap:DeferredDerivativeGainLoss


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.045-0.077-0.183-0.136-0.4590.466-0.0780.133-0.2460.0890.284-0.210.0560.154
Percentage of GainLossOnDerivativeInstrumentsNetPretax0.01925.0653.6-141.7-361.4-125.688.645.739.125.8112.3214.341.8-194.9

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity


Income
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value6241000.0765000.0280000.0-778000.0-1608000.0-795000.0-956000.0-217000.0-959000.0-650000.0-659000.0-474000.0-124660000.0-608000.0-1346000.0-1087000.0
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationsHeldforsale, nwn:GillRanch


Income
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6241000.0765000.0280000.0-778000.0-1608000.0-795000.0-956000.0-217000.0-959000.0-650000.0-659000.0-474000.0
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate


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
Value-0.211612-5.048-1.429137.87-6.5070.694148.125-4.136-0.1351515-5.44
Percentage of IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.1841612-5.518-1.287138.075-6.1771.055148.353-4.183-0.10715
Percentage of IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate-87.6100.8101.1109.390.1101.9102.694.9152.0101.2102.8101.179.3100.0

us-gaap:IncomeTaxReconciliationOtherAdjustments

us-gaap:IncomeTaxReconciliationOtherAdjustments


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
Value-40000.010000.0-405000.086000.0-83000.0-130000.0-913000.074000.0-32000.0-378000.0-709000.0117000.0-7000.0-585000.0-1319000.020000.0
Percentage of IncomeTaxReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationOtherAdjustments dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value42000.0-107000.0-410000.05000.0-24000.0-149000.0-852000.074000.0-33000.0-377000.0-708000.0116000.0-7000.0-586000.0
Percentage of IncomeTaxReconciliationOtherAdjustments-105.0-1070.0101.25.828.9114.693.3100.0103.199.799.999.1100.0100.2

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-48000.07308000.04497000.0-1452000.0-333000.03677000.02625000.0-1708000.0214000.03291000.0
Percentage of IncomeTaxReconciliationStateAndLocalIncomeTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value41000.07325000.04524000.0-1595000.0-281000.03737000.02741000.0-1641000.0290000.03326000.0
Percentage of IncomeTaxReconciliationStateAndLocalIncomeTaxes-85.4100.2100.6109.884.4101.6104.496.1135.5101.1

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-72.089-1.04494-3.282-69.109-4.84574-11.169-73.9274.89183-3.862-68.78-10.55287
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-73.933-0.42194-3.592-71.827-2.79874-10.395-78.1814.99587-3.783-68.781-10.552
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables102.640.3100.8109.4103.957.899.993.1105.8102.1104.898.0100.0100.0

us-gaap:IncreaseDecreaseInAccruedTaxesPayable

us-gaap:IncreaseDecreaseInAccruedTaxesPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-1.50822-22.748-8.928-0.94521-16.9825.218.8947.406-11.0956.158-5.102-6.8656.95
Percentage of IncreaseDecreaseInAccruedTaxesPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccruedTaxesPayable dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-2.04821-11.2720.0660.2921-13.0096.3062.1625.037-2.0446.147-5.097-6.86
Percentage of IncreaseDecreaseInAccruedTaxesPayable135.893.549.6-0.7-30.799.376.6121.024.368.018.499.899.999.9

us-gaap:IncreaseDecreaseInDeferredGasCost

us-gaap:IncreaseDecreaseInDeferredGasCost


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-1.9528-20.0622.5878.124-8.239-23.6142.2352519162.415-1.268-3.519-3.703
Percentage of IncreaseDecreaseInDeferredGasCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredGasCost dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1.9528-20.0622.5878.124-8.239-23.6142.2352519162.415-1.268-3.519
Percentage of IncreaseDecreaseInDeferredGasCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInterestPayableNet

us-gaap:IncreaseDecreaseInInterestPayableNet


Increase
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value2411000.0-2162000.01945000.0-2955000.02580000.0-1407000.01927000.0-2154000.02801000.0-2610000.02489000.0-3081000.0
Percentage of IncreaseDecreaseInInterestPayableNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInterestPayableNet dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2396000.0-2212000.01927000.0-2964000.02730000.0-1550000.01952000.0-2180000.02801000.0-2610000.02489000.0
Percentage of IncreaseDecreaseInInterestPayableNet99.4102.399.1100.3105.8110.2101.3101.2100.0100.0100.0

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-2.239-34.6331.2910.1061.856-6.137-7.566-2.46-0.732-7.903-1.5821.6980.818-5.431
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-71.505341.2910.1061.856-6.137-7.566-2.46-0.732-7.903-1.5821.6980.818-5.431
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities3193.6-100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements


Incremental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value13000.019000.011000.02000.0044000.08000.0057000.064000.011000.00050000.03000.00
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.00.00.0100.0100.00.0

us-gaap:LeaseIncome

us-gaap:LeaseIncome


Lease
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value4.3934.3874.6064.6064.6134.6184.1874.9432.1320.108
Percentage of LeaseIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseExpense

us-gaap:OperatingLeaseExpense


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1728000.01696000.01535000.0763000.0954000.01254000.01217000.01205000.01201000.01188000.0
Percentage of OperatingLeaseExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseExpense dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1710000.01678000.01519000.0746000.0914000.01202000.01165000.01158000.01155000.01142000.0
Percentage of OperatingLeaseExpense99.098.999.097.895.895.995.796.196.296.1

us-gaap:OperatingLeaseExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value18000.018000.016000.017000.040000.052000.052000.047000.046000.046000.0
Percentage of OperatingLeaseExpense1.01.11.02.24.24.14.33.93.83.9

us-gaap:OperatingLeaseLeaseIncome

us-gaap:OperatingLeaseLeaseIncome


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0250.0180.0170.0180.0250.0280.0280.0480.0470.048
Percentage of OperatingLeaseLeaseIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseLeaseIncome dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

nwn:NorthwestNaturalGasCompany, us-gaap:OperatingSegments, nwn:Leasingrevenue, nwn:NaturalGasDistribution


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.3934.3874.6064.6064.6134.6184.1874.9432.1320.1080.0690.7250.1260.076
Percentage of OperatingLeaseLeaseIncome17572.024372.227094.125588.918452.016492.914953.610297.94536.2225.00.00.00.00.0

us-gaap:OperatingLeaseLeaseIncome dei:LegalEntity, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

nwn:NorthwestNaturalGasCompany, nwn:Leasingrevenue, nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.3934.3874.6064.6064.6134.6184.1874.9432.1320.1080.0690.7250.1260.076
Percentage of OperatingLeaseLeaseIncome17572.024372.227094.125588.918452.016492.914953.610297.94536.2225.00.00.00.00.0

us-gaap:OperatingLeaseLeaseIncome us-gaap:ProductOrService

nwn:Leasingrevenue


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.3934.3874.6064.6064.6134.6184.1874.9432.1320.1080.0690.7250.1260.076
Percentage of OperatingLeaseLeaseIncome17572.024372.227094.125588.918452.016492.914953.610297.94536.2225.00.00.00.00.0

us-gaap:OperatingLeasePayments

us-gaap:OperatingLeasePayments


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1734000.01685000.01688000.0691000.0970000.01248000.01178000.01158000.01159000.01134000.0
Percentage of OperatingLeasePayments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeasePayments dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1717000.01669000.01666000.0673000.0931000.01196000.01128000.01113000.01115000.01091000.0
Percentage of OperatingLeasePayments99.099.198.797.496.095.895.896.196.296.2

us-gaap:OperatingLeasePayments us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, nwn:OtherNorthwestHoldings


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value17000.016000.022000.018000.039000.052000.050000.045000.044000.043000.0
Percentage of OperatingLeasePayments1.00.91.32.64.04.24.23.93.83.8

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value80000.080000.066000.058000.058000.043000.041000.041000.055000.056000.055000.098000.0
Percentage of OtherComprehensiveIncomeDefinedBenefitPlansTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax


Other
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value80000.066000.058000.058000.043000.041000.041000.0-444000.055000.056000.055000.0
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value80000.080000.066000.058000.058000.043000.041000.041000.0-444000.055000.056000.055000.0
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value301000.0301000.0252000.0218000.0218000.0157000.0156000.0-1210000.0209000.0209000.0209000.0248000.0
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value221000.0221000.0186000.0160000.0160000.0114000.0115000.0-1251000.0154000.0153000.0154000.0150000.0
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value301000.0301000.0252000.0218000.0218000.0157000.0156000.0156000.0209000.0209000.0209000.0248000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value221000.0221000.0173000.0186000.0160000.0160000.0132000.0114000.0115000.0115000.0313000.0154000.0153000.0154000.0149000.0150000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value221000.0221000.0173000.0186000.0160000.0160000.0132000.0114000.0115000.0115000.0313000.0154000.0153000.0154000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherCostAndExpenseOperating


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value815000.0932000.01455000.0767000.0551000.0928000.01119000.0593000.0646000.0892000.01070000.0625000.0679000.0853000.000
Percentage of OtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

us-gaap:OtherCostAndExpenseOperating dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value780000.0919000.01065000.0725000.0522000.0920000.01116000.0586000.0638000.0890000.01067000.0624000.0679000.0853000.0
Percentage of OtherCostAndExpenseOperating95.798.673.294.594.799.199.798.898.899.899.799.8100.0100.0

us-gaap:OtherIncreaseDecreaseInEnvironmentalLiabilities

us-gaap:OtherIncreaseDecreaseInEnvironmentalLiabilities


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-5355000.0-4270000.0-11402000.0-6572000.0-5916000.0-3981000.0-5234000.0-3844000.0-3463000.0-3685000.0-3981000.0-3217000.0-6050000.0-1280000.0-3248000.0
Percentage of OtherIncreaseDecreaseInEnvironmentalLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherIncreaseDecreaseInEnvironmentalLiabilities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value-5355000.0-4270000.0-11402000.0-6572000.0-5916000.0-3981000.0-5234000.0-3844000.0-3463000.0-3685000.0-3981000.0-3217000.0-6050000.0-1280000.0
Percentage of OtherIncreaseDecreaseInEnvironmentalLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNoncashIncomeExpense

us-gaap:OtherNoncashIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-4529000.02919000.02459000.0-1448000.012430000.0-6499000.0-4849000.0-2776000.0-3111000.0-3171000.0-55000.0-731000.069000.0-879000.0420000.0
Percentage of OtherNoncashIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherNoncashIncomeExpense dei:LegalEntity

nwn:NorthwestNaturalGasCompany


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
Value-4080000.03599000.02615000.0-2336000.012807000.0-6061000.0-4414000.0-2340000.0-2446000.0-3117000.01026000.0-729000.0-326000.0-854000.0
Percentage of OtherNoncashIncomeExpense90.1123.3106.3161.3103.093.391.084.378.698.3-1865.599.7-472.597.2

us-gaap:PaymentsForCapitalImprovements

us-gaap:PaymentsForCapitalImprovements


Payments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.1090.0540.3081.1946.3259.232.8570.94
Percentage of PaymentsForCapitalImprovements100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForCapitalImprovements dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Payments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.1090.0540.3081.1946.3259.232.8570.94
Percentage of PaymentsForCapitalImprovements100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsForProceedsFromOtherInvestingActivities


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-0.2460.037-1.8940.5030.656-0.919-12.575103.3981.9911.7291.856-0.2530.058-0.554
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.2460.037-1.8880.5030.65-0.919-12.575103.3981.9910.722.992-0.2520.057
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.099.7100.099.1100.0100.0100.0100.0100.041.6161.299.698.3

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.0130.0420.1850.1380.057370.5970.378550.01.009-0.136
Percentage of PaymentsToAcquireBusinessesNetOfCashAcquired100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0

us-gaap:PaymentsToAcquireOilAndGasPropertyAndEquipment

us-gaap:PaymentsToAcquireOilAndGasPropertyAndEquipment


Payments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value6465716457614248
Percentage of PaymentsToAcquireOilAndGasPropertyAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireOilAndGasPropertyAndEquipment dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Payments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value6164706156614248
Percentage of PaymentsToAcquireOilAndGasPropertyAndEquipment94.897.699.095.697.999.099.199.8

us-gaap:PensionAndOtherPostretirementBenefitContributions

us-gaap:PensionAndOtherPostretirementBenefitContributions


Pension
Period End2021-06-302021-03-31
Value5.14.5
Percentage of PensionAndOtherPostretirementBenefitContributions100.0100.0

us-gaap:PensionContributions

us-gaap:PensionContributions


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value5.054.545.31155.313.163.163.163.161.493.856.123.851.724.03
Percentage of PensionContributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionContributions dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value5.054.545.31155.313.163.163.163.161.493.856.123.851.72
Percentage of PensionContributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionExpense

us-gaap:PensionExpense


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value3.9373.9374.574.9084.4464.4466.0333.4763.4893.4993.6581.5741.4411.4351.441
Percentage of PensionExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionExpense dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3.9373.9374.574.9084.4464.4466.0333.4763.4893.4993.6581.5741.4411.435
Percentage of PensionExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:ProceedsFromIssuanceOfDebt

nwn:NorthwestNaturalGasCompany, nwn:A364DayTermLoanDue2021


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.00.0150
Percentage of ProceedsFromIssuanceOfDebt0.00.0100.0

nwn:NorthwestNaturalGasCompany, nwn:Note3.60SeriesDue2050


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.00.0150
Percentage of ProceedsFromIssuanceOfDebt0.00.0100.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-201000.0-974000.0-339000.050000.0-870000.0-2137000.0-2242000.0-463000.01027000.0-936000.0-424000.0-12000.030000.0-309000.0-297000.0
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-114000.0-1509000.0-288000.0-204000.0-950000.0-2190000.0-2167000.0-420000.01110000.0-1033000.0-1248000.0-57000.075000.0-309000.0
Percentage of ProceedsFromPaymentsForOtherFinancingActivities56.7154.985.0-408.0109.2102.596.790.7108.1110.4294.3475.0250.0100.0

us-gaap:ProceedsFromRepaymentsOfLinesOfCredit

us-gaap:ProceedsFromRepaymentsOfLinesOfCredit


Proceeds
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-10.0-317.025045-156.311-41.229
Percentage of ProceedsFromRepaymentsOfLinesOfCredit100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromRepaymentsOfLinesOfCredit dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Proceeds
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-3.0-297.017445-176.3-41.2
Percentage of ProceedsFromRepaymentsOfLinesOfCredit30.093.769.7100.0112.899.9

us-gaap:ProceedsFromSaleOfEquityMethodInvestments

us-gaap:ProceedsFromSaleOfEquityMethodInvestments


Proceeds
Period End2020-12-31
Value0.0
Percentage of ProceedsFromSaleOfEquityMethodInvestments0.0

us-gaap:ProceedsFromSaleOfEquityMethodInvestments us-gaap:BalanceSheetLocation, us-gaap:SubsequentEventType

us-gaap:CashAndCashEquivalents, us-gaap:SubsequentEvent


Proceeds
Period End2020-09-30
Value7.0
Percentage of ProceedsFromSaleOfEquityMethodInvestments0.0

us-gaap:NotesReceivable, us-gaap:SubsequentEvent


Proceeds
Period End2020-09-30
Value7.0
Percentage of ProceedsFromSaleOfEquityMethodInvestments0.0

us-gaap:ProceedsFromSaleOfEquityMethodInvestments us-gaap:StatementScenario, us-gaap:BalanceSheetLocation

srt:ScenarioForecast, us-gaap:CashAndCashEquivalents


Proceeds
Period End2020-09-30
Value7.0
Percentage of ProceedsFromSaleOfEquityMethodInvestments0.0

srt:ScenarioForecast, us-gaap:NotesReceivable


Proceeds
Period End2020-09-30
Value7.0
Percentage of ProceedsFromSaleOfEquityMethodInvestments0.0

us-gaap:ProceedsFromSaleOfLandHeldForUse

us-gaap:ProceedsFromSaleOfLandHeldForUse


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value274000.01960000.0146000.098000.07621000.0284000.0378000.031000.0
Percentage of ProceedsFromSaleOfLandHeldForUse100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfLandHeldForUse dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value274000.01960000.0146000.098000.07621000.0284000.0378000.031000.0
Percentage of ProceedsFromSaleOfLandHeldForUse100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromShortTermDebt

us-gaap:ProceedsFromShortTermDebt


Proceeds
Period End2020-09-302020-06-302020-03-312019-06-302019-03-31
Value0.00.01500.00.0
Percentage of ProceedsFromShortTermDebt0.00.0100.00.00.0

us-gaap:ProceedsFromShortTermDebt dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Proceeds
Period End2020-09-302020-06-302020-03-312019-06-302019-03-31
Value0.00.01500.00.0
Percentage of ProceedsFromShortTermDebt0.00.0100.00.00.0

us-gaap:ProceedsFromStockOptionsExercised

us-gaap:ProceedsFromStockOptionsExercised


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value068000.0-68000.068000.0292000.00177000.01546000.0178000.01323000.045000.001108000.0
Percentage of ProceedsFromStockOptionsExercised0.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0

us-gaap:RegulatedOperatingRevenueOther us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:RegulatedOperatingRevenueOther

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Regulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value4.7654.7854.8714.4044.9214.9264.6595.1472.1920.0580.0430.1120.08
Percentage of RegulatedOperatingRevenueOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfDebt dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:SubsequentEventType

us-gaap:RepaymentsOfDebt

nwn:NorthwestNaturalGasCompany, nwn:A364DayTermLoanDue2021, us-gaap:SubsequentEvent


Repayments
Period End2020-12-31
Value150
Percentage of RepaymentsOfDebt100.0

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value20000.074000.00676000.0477000.0233000.000
Percentage of RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability100.0100.00.0100.0100.0100.00.00.0

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value20000.074000.00676000.0477000.0233000.000
Percentage of RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability100.0100.00.0100.0100.0100.00.00.0

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.00.1540.0510.1060.445770.2190.0670.07.291
Percentage of RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability0.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.00.1540.00.1060.445770.1510.0670.06.987
Percentage of RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability0.0100.00.0100.0100.0100.068.9100.00.095.8

us-gaap:SalesTypeLeaseLeaseIncome

us-gaap:SalesTypeLeaseLeaseIncome


Sales
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value4.3684.3694.5894.5884.5884.594.1594.8952.0850.06
Percentage of SalesTypeLeaseLeaseIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShortTermLeaseCost

us-gaap:ShortTermLeaseCost


Short
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value349000.0220000.0227000.0300000.0285000.0198000.0332000.0323000.0331000.0160000.0
Percentage of ShortTermLeaseCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShortTermLeaseCost dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Short
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value349000.0220000.0227000.0300000.0285000.0198000.0332000.0323000.0331000.0160000.0
Percentage of ShortTermLeaseCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueEmployeeStockPurchasePlan us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueEmployeeStockPurchasePlan

us-gaap:CommonStockIncludingAdditionalPaidInCapital


Stock
Period End2021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value924000.0627000.01248000.0-390000.01082000.01589000.01047000.01282000.02487000.01035000.0371000.0
Percentage of StockIssuedDuringPeriodValueEmployeeStockPurchasePlan100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation

us-gaap:CommonStockIncludingAdditionalPaidInCapital


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value416000.02030000.0-1622000.0459000.0254000.03378000.02776000.0485000.0579000.01245000.0859000.0237000.0752000.01172000.0
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TaxesExcludingIncomeAndExciseTaxes

us-gaap:TaxesExcludingIncomeAndExciseTaxes


Taxes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value8.914118.1548.6568.3739.8957.4897.9937.8799.0277.387.5897.7299.4747.2167.54
Percentage of TaxesExcludingIncomeAndExciseTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TaxesExcludingIncomeAndExciseTaxes dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Taxes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.783117.8958.5548.2119.7997.387.8817.8268.9887.3227.5847.7219.459
Percentage of TaxesExcludingIncomeAndExciseTaxes98.599.096.898.898.199.098.598.699.399.699.299.999.999.8

us-gaap:UnrealizedGainLossOnDerivatives

us-gaap:UnrealizedGainLossOnDerivatives


Unrealized
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value3321-21.0285.5-0.22.3-4.1-0.5
Percentage of UnrealizedGainLossOnDerivatives100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value4111289234110891223510579254210810027
Percentage of UtilitiesOperatingExpenseGasAndPetroleumPurchased100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value41112892341108912235105792542108
Percentage of UtilitiesOperatingExpenseGasAndPetroleumPurchased100.1100.0100.1100.2100.1100.1100.1100.2100.2100.1100.1100.2100.1100.1

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value41112892341108912235105792542108
Percentage of UtilitiesOperatingExpenseGasAndPetroleumPurchased100.1100.0100.1100.2100.1100.1100.1100.2100.2100.1100.1100.2100.1100.1

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses

nwn:NorthwestNaturalGasCompany


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4449423841464337375040373739
Percentage of UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UtilitiesOperatingExpenseTaxes us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:UtilitiesOperatingExpenseTaxes

us-gaap:OperatingSegments, nwn:NaturalGasDistribution


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value5.6512103.5554.45411103.5344.496119.3513.5224.7812
Percentage of UtilitiesOperatingExpenseTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:EntityCommonStockSharesOutstanding

dei:EntityCommonStockSharesOutstanding


Entity
Period End2021-07-232021-04-262021-02-162020-10-292019-02-222018-10-26
Value303030302828
Percentage of EntityCommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0

nwn:CumulativeGrossInvestment dei:LegalEntity

nwn:CumulativeGrossInvestment

nwn:NorthwestNaturalGasCompany


Cumulative
Period End2020-12-31
Value10000000.0
Percentage of CumulativeGrossInvestment100.0

nwn:DeferredTaxAssetsLeaseLiabilities

nwn:DeferredTaxAssetsLeaseLiabilities


Deferred
Period End2020-12-312019-12-31
Value210.775
Percentage of DeferredTaxAssetsLeaseLiabilities100.0100.0

nwn:DeferredTaxAssetsLeaseLiabilities dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2020-12-312019-12-31
Value210.728
Percentage of DeferredTaxAssetsLeaseLiabilities99.993.9

nwn:DeferredTaxLiabilitiesLeaseRightOfUseAssets

nwn:DeferredTaxLiabilitiesLeaseRightOfUseAssets


Deferred
Period End2020-12-312019-12-31
Value210.778
Percentage of DeferredTaxLiabilitiesLeaseRightOfUseAssets100.0100.0

nwn:DeferredTaxLiabilitiesLeaseRightOfUseAssets dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2020-12-312019-12-31
Value210.731
Percentage of DeferredTaxLiabilitiesLeaseRightOfUseAssets99.994.0

nwn:DeferredTaxesRelatedToGasReserves

nwn:DeferredTaxesRelatedToGasReserves


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
Value8.769.8311011131415132619201920222229
Percentage of DeferredTaxesRelatedToGasReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:DeferredTaxesRelatedToGasReserves dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Deferred
Period End2020-12-312019-12-312018-12-312017-12-31
Value10152022
Percentage of DeferredTaxesRelatedToGasReserves100.0100.0100.0100.0

nwn:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets us-gaap:RetirementPlanType

nwn:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value7.250.07250.0750.0750.075
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationExpectedLongTermReturnOnAssets100.0100.0100.0100.0100.0

nwn:DefinedBenefitPlanHealthCareCostTrendRateAssumedThereafter

nwn:DefinedBenefitPlanHealthCareCostTrendRateAssumedThereafter


Defined
Period End2020-12-31
Value3.5
Percentage of DefinedBenefitPlanHealthCareCostTrendRateAssumedThereafter100.0

nwn:DiscontinuedOperationOperatingLeaseLiabilities us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

nwn:DiscontinuedOperationOperatingLeaseLiabilities

us-gaap:DiscontinuedOperationsHeldForSaleOrDisposedOfBySale, nwn:GillRanch


Discontinued
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value113000.0112000.0110000.0116000.0114000.0113000.0111000.00000
Percentage of DiscontinuedOperationOperatingLeaseLiabilities100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

nwn:DiscontinuedOperationOperatingleaseRightofUseAsset us-gaap:DisposalGroupClassification, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

nwn:DiscontinuedOperationOperatingleaseRightofUseAsset

us-gaap:DiscontinuedOperationsHeldForSaleOrDisposedOfBySale, nwn:GillRanch


Discontinued
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value118000.0118000.0118000.0118000.0118000.0118000.0118000.00000
Percentage of DiscontinuedOperationOperatingleaseRightofUseAsset100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

nwn:EPARecordOfDecisionCleanUpCostsPortlandHarbor dei:LegalEntity, us-gaap:Range

nwn:EPARecordOfDecisionCleanUpCostsPortlandHarbor

nwn:NorthwestNaturalGasCompany, srt:Maximum


E
Period End2020-12-312019-12-312018-12-31
Value5e-055e-075e-07
Percentage of EPARecordOfDecisionCleanUpCostsPortlandHarbor100.0100.0100.0

nwn:NorthwestNaturalGasCompany, srt:Minimum


E
Period End2020-12-312019-12-312018-12-31
Value-3e-05-3e-07-3e-07
Percentage of EPARecordOfDecisionCleanUpCostsPortlandHarbor-60.0-60.0-60.0

nwn:EnvironmentalProjectLiability dei:LegalEntity, us-gaap:EnvironmentalRemediationSite

nwn:EnvironmentalProjectLiability

nwn:NorthwestNaturalGasCompany, nwn:GascoSiltronicSediments


Environmental
Period End2020-12-31
Value51
Percentage of EnvironmentalProjectLiability100.0

nwn:EnvironmentalRegulatoryAccruedSiteLiabilities dei:LegalEntity, nwn:EnvironmentalActivity, us-gaap:RegulatoryAsset

nwn:EnvironmentalRegulatoryAccruedSiteLiabilities

nwn:NorthwestNaturalGasCompany, nwn:FrontStreet, us-gaap:EnvironmentalRestorationCosts


Environmental
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.20.40.40.4
Percentage of EnvironmentalRegulatoryAccruedSiteLiabilities100.0100.0100.0100.0

nwn:EnvironmentalRegulatoryAccruedSiteLiabilities dei:LegalEntity, us-gaap:RegulatoryAsset

nwn:NorthwestNaturalGasCompany, us-gaap:EnvironmentalRestorationCosts


Environmental
Period End2020-12-312019-12-312019-03-312018-12-312018-03-312017-12-31
Value120135124128122126
Percentage of EnvironmentalRegulatoryAccruedSiteLiabilities60176.033915.50.032092.20.031737.5

nwn:EnvironmentalRegulatoryDeferredCostandInterest dei:LegalEntity, us-gaap:RegulatoryAsset

nwn:EnvironmentalRegulatoryDeferredCostandInterest

nwn:NorthwestNaturalGasCompany, us-gaap:EnvironmentalRestorationCosts


Environmental
Period End2020-12-312019-12-312019-03-312018-12-312018-03-312017-12-31
Value443636414445
Percentage of EnvironmentalRegulatoryDeferredCostandInterest100.0100.0100.0100.0100.0100.0

nwn:EnvironmentalRegulatoryInsuranceProceedsandInterest dei:LegalEntity, us-gaap:RegulatoryAsset

nwn:EnvironmentalRegulatoryInsuranceProceedsandInterest

nwn:NorthwestNaturalGasCompany, us-gaap:EnvironmentalRestorationCosts


Environmental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-69730000.0-69492000.0-69253000.0-69138000.0-81146000.0-80613000.0-79949000.0-80741000.0-90119000.0-89305000.0-88502000.0-87631000.0-95824000.0-95100000.0-94170000.0
Percentage of EnvironmentalRegulatoryInsuranceProceedsandInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:EnvironmentalSettlementInsuranceProceedsReceivedToDate dei:LegalEntity

nwn:EnvironmentalSettlementInsuranceProceedsReceivedToDate

nwn:NorthwestNaturalGasCompany


Environmental
Period End2020-12-31
Value150
Percentage of EnvironmentalSettlementInsuranceProceedsReceivedToDate100.0

nwn:GasReservesAmortization

nwn:GasReservesAmortization


Gas
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1491451411371321271231181131091049995918783
Percentage of GasReservesAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:GasReservesAmortization dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Gas
Period End2020-12-312019-12-312018-12-312017-12-31
Value14112310487
Percentage of GasReservesAmortization100.0100.0100.0100.0

nwn:GasReservesInvestment dei:LegalEntity

nwn:GasReservesInvestment

nwn:NorthwestNaturalGasCompany


Gas
Period End2020-12-31
Value178
Percentage of GasReservesInvestment100.0

nwn:GasReservesNoncurrentGross

nwn:GasReservesNoncurrentGross


Gas
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value178176175175173172172170170171170170170172171171
Percentage of GasReservesNoncurrentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:GasReservesNoncurrentGross dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Gas
Period End2020-12-312019-12-312018-12-312017-12-31
Value175172170171
Percentage of GasReservesNoncurrentGross100.0100.0100.0100.0

nwn:InsuranceProceedsAppliedToPrudentlyIncurredRemediationCosts dei:LegalEntity

nwn:InsuranceProceedsAppliedToPrudentlyIncurredRemediationCosts

nwn:NorthwestNaturalGasCompany


Insurance
Period End2020-12-31
Value83
Percentage of InsuranceProceedsAppliedToPrudentlyIncurredRemediationCosts100.0

nwn:InvestmentinAdditionalWellsGasReserves dei:LegalEntity

nwn:InvestmentinAdditionalWellsGasReserves

nwn:NorthwestNaturalGasCompany


Investmentin
Period End2020-12-312019-12-312018-12-312017-12-31
Value3000000.03800000.04800000.05800000.0
Percentage of InvestmentinAdditionalWellsGasReserves100.0100.0100.0100.0

nwn:InvestmentsinSubsidiaries us-gaap:ConsolidatedEntities

nwn:InvestmentsinSubsidiaries

nwn:ParentCompanyCondensedBalanceSheet


Investmentsin
Period End2020-12-312019-12-312018-12-31
Value939888754
Percentage of InvestmentsinSubsidiaries100.0100.0100.0

nwn:LeasePaymentstobeReceived

nwn:LeasePaymentstobeReceived


Lease
Period End2021-06-302021-03-312020-12-312020-09-30
Value326330334338
Percentage of LeasePaymentstobeReceived100.0100.0100.0100.0

nwn:LeasePaymentstobeReceived dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value325
Percentage of LeasePaymentstobeReceived99.6

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value1.201
Percentage of LeasePaymentstobeReceived0.4

nwn:LeasePaymentstobeReceivedFiveYears

nwn:LeasePaymentstobeReceivedFiveYears


Lease
Period End2021-06-302021-03-312020-12-312020-09-30
Value15151515
Percentage of LeasePaymentstobeReceivedFiveYears100.0100.0100.0100.0

nwn:LeasePaymentstobeReceivedFiveYears dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value15
Percentage of LeasePaymentstobeReceivedFiveYears99.7

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value0.053
Percentage of LeasePaymentstobeReceivedFiveYears0.3

nwn:LeasePaymentstobeReceivedFourYears

nwn:LeasePaymentstobeReceivedFourYears


Lease
Period End2021-06-302021-03-312020-12-312020-09-30
Value15151516
Percentage of LeasePaymentstobeReceivedFourYears100.0100.0100.0100.0

nwn:LeasePaymentstobeReceivedFourYears dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value15
Percentage of LeasePaymentstobeReceivedFourYears99.7

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value0.052
Percentage of LeasePaymentstobeReceivedFourYears0.3

nwn:LeasePaymentstobeReceivedNexttwelvemonths

nwn:LeasePaymentstobeReceivedNexttwelvemonths


Lease
Period End2020-12-31
Value17
Percentage of LeasePaymentstobeReceivedNexttwelvemonths100.0

nwn:LeasePaymentstobeReceivedRemainderofFiscalYear

nwn:LeasePaymentstobeReceivedRemainderofFiscalYear


Lease
Period End2021-06-302021-03-312020-09-30
Value8.762134.527
Percentage of LeasePaymentstobeReceivedRemainderofFiscalYear100.0100.0100.0

nwn:LeasePaymentstobeReceivedRemainderofFiscalYear dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value8.737
Percentage of LeasePaymentstobeReceivedRemainderofFiscalYear99.7

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value0.025
Percentage of LeasePaymentstobeReceivedRemainderofFiscalYear0.3

nwn:LeasePaymentstobeReceivedThereafter

nwn:LeasePaymentstobeReceivedThereafter


Lease
Period End2021-06-302021-03-312020-12-312020-09-30
Value252251251267
Percentage of LeasePaymentstobeReceivedThereafter100.0100.0100.0100.0

nwn:LeasePaymentstobeReceivedThereafter dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value251
Percentage of LeasePaymentstobeReceivedThereafter99.6

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value0.97
Percentage of LeasePaymentstobeReceivedThereafter0.4

nwn:LeasePaymentstobeReceivedThreeYears

nwn:LeasePaymentstobeReceivedThreeYears


Lease
Period End2021-06-302021-03-312020-12-312020-09-30
Value16161617
Percentage of LeasePaymentstobeReceivedThreeYears100.0100.0100.0100.0

nwn:LeasePaymentstobeReceivedThreeYears dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value16
Percentage of LeasePaymentstobeReceivedThreeYears99.7

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value0.051
Percentage of LeasePaymentstobeReceivedThreeYears0.3

nwn:LeasePaymentstobeReceivedTwoYears

nwn:LeasePaymentstobeReceivedTwoYears


Lease
Period End2021-06-302021-03-312020-12-312020-09-30
Value17171717
Percentage of LeasePaymentstobeReceivedTwoYears100.0100.0100.0100.0

nwn:LeasePaymentstobeReceivedTwoYears dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Lease
Period End2021-06-30
Value17
Percentage of LeasePaymentstobeReceivedTwoYears99.7

nwn:OtherNorthwestHoldings


Lease
Period End2021-06-30
Value0.05
Percentage of LeasePaymentstobeReceivedTwoYears0.3

nwn:LiabilityForStudiesAndDesignCosts dei:LegalEntity, us-gaap:EnvironmentalRemediationSite

nwn:LiabilityForStudiesAndDesignCosts

nwn:NorthwestNaturalGasCompany, nwn:FrontStreet


Liability
Period End2020-12-31
Value4900000.0
Percentage of LiabilityForStudiesAndDesignCosts100.0

nwn:LongTermDebtCurrentMaturitiesGross dei:LegalEntity

nwn:LongTermDebtCurrentMaturitiesGross

nwn:NorthwestNaturalGasCompany


Long
Period End2020-12-312019-12-312018-12-31
Value607530
Percentage of LongTermDebtCurrentMaturitiesGross100.0100.0100.0

nwn:LongtermDebtExcludingCurrentMaturitiesGross dei:LegalEntity

nwn:LongtermDebtExcludingCurrentMaturitiesGross

nwn:NorthwestNaturalGasCompany


Longterm
Period End2020-12-312019-12-312018-12-31
Value864774709
Percentage of LongtermDebtExcludingCurrentMaturitiesGross100.0100.0100.0

nwn:NetGasReservesInvestment

nwn:NetGasReservesInvestment


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
Value29323537414548554658626871737774
Percentage of NetGasReservesInvestment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NetGasReservesInvestment dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Net
Period End2020-12-312019-12-312018-12-312017-12-31
Value35486277
Percentage of NetGasReservesInvestment100.0100.0100.0100.0

nwn:PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccount dei:LegalEntity, us-gaap:StatementBusinessSegments

nwn:PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccount

nwn:NorthwestHoldingsandNorthwestNatural, nwn:NaturalGasDistribution


Percent
Period End2020-12-31
Value20.0
Percentage of PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccount100.0

nwn:PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccountWhenInRates dei:LegalEntity, us-gaap:StatementBusinessSegments

nwn:PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccountWhenInRates

nwn:NorthwestHoldingsandNorthwestNatural, nwn:NaturalGasDistribution


Percent
Period End2020-12-31
Value90.0
Percentage of PercentOfPreTaxIncomeFromGasStorageCreditedToDeferredRegulatoryAccountWhenInRates100.0

nwn:PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreInUtilityRates dei:LegalEntity, us-gaap:StatementBusinessSegments

nwn:PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreInUtilityRates

nwn:NorthwestHoldingsandNorthwestNatural, nwn:NaturalGasDistribution


Percent
Period End2020-12-31
Value10.0
Percentage of PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreInUtilityRates100.0

nwn:PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreNotInUtilityRates dei:LegalEntity, us-gaap:StatementBusinessSegments

nwn:PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreNotInUtilityRates

nwn:NorthwestHoldingsandNorthwestNatural, nwn:NaturalGasDistribution


Percent
Period End2020-12-31
Value80.0
Percentage of PercentOfPreTaxIncomeFromGasStorageRetainedWhenCostsOfCapacityAreNotInUtilityRates100.0

nwn:PercentOwnershipInJointProject us-gaap:Ownership

nwn:PercentOwnershipInJointProject

nwn:GillRanch


Percent
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value75.075.075.075.00.750.750.750.750.750.750.750.75
Percentage of PercentOwnershipInJointProject100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:PacificGasandElectricCompany


Percent
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value25.00.250.250.250.250.250.250.250.25
Percentage of PercentOwnershipInJointProject33.333.333.333.333.333.333.333.333.3

nwn:PlanAssetReceivableOrPayableAccruedInterestAndDividendIncome dei:LegalEntity, us-gaap:RetirementPlanType

nwn:PlanAssetReceivableOrPayableAccruedInterestAndDividendIncome

nwn:NorthwestNaturalGasCompany, us-gaap:PensionPlansDefinedBenefit


Plan
Period End2020-12-312019-12-312018-12-312017-12-31
Value6429000.03243000.01000.030000.0
Percentage of PlanAssetReceivableOrPayableAccruedInterestAndDividendIncome100.0100.0100.0100.0

nwn:PlanAssetReceivableOrPayableDueFromBrokerSecuritiesPurchased dei:LegalEntity, us-gaap:RetirementPlanType

nwn:PlanAssetReceivableOrPayableDueFromBrokerSecuritiesPurchased

nwn:NorthwestNaturalGasCompany, us-gaap:PensionPlansDefinedBenefit


Plan
Period End2020-12-312019-12-312018-12-312017-12-31
Value6429000.03242000.000
Percentage of PlanAssetReceivableOrPayableDueFromBrokerSecuritiesPurchased100.0100.00.00.0

nwn:PropertyPlantEquipmentnoncash us-gaap:StatementBusinessSegments

nwn:PropertyPlantEquipmentnoncash

nwn:NorthwestHoldings


Property
Period End2021-06-302021-03-312020-12-312020-06-302020-03-31
Value0.0383950.0211180.0251290.0318470.033999
Percentage of PropertyPlantEquipmentnoncash100.0100.0100.0100.0100.0

nwn:NorthwestHoldingsandNorthwestNatural


Property
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value25373133323532252327222134
Percentage of PropertyPlantEquipmentnoncash100000.00.0100000.0100000.00.00.00.00.00.00.00.00.00.0

nwn:NorthwestNaturalGasCompany


Property
Period End2021-06-302021-03-312020-12-312020-06-302020-03-31
Value3720253133
Percentage of PropertyPlantEquipmentnoncash98887.999294.4100000.0100000.0100000.0

nwn:RegulatoryAssetsActuarialGainLoss us-gaap:RegulatoryAsset

nwn:RegulatoryAssetsActuarialGainLoss

us-gaap:PensionCosts


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-31
Value164166170175
Percentage of RegulatoryAssetsActuarialGainLoss100.0100.0100.0100.0

us-gaap:PostretirementBenefitCosts


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-31
Value7.1677.6296.1896.964
Percentage of RegulatoryAssetsActuarialGainLoss4.44.63.64.0

nwn:RegulatoryAssetsEnvironmentalRegulatoryAccruedSiteLiabilities dei:LegalEntity, us-gaap:RegulatoryAsset

nwn:RegulatoryAssetsEnvironmentalRegulatoryAccruedSiteLiabilities

nwn:NorthwestNaturalGasCompany, us-gaap:EnvironmentalRestorationCosts


Regulatory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value110113120122124129135118120124128116119
Percentage of RegulatoryAssetsEnvironmentalRegulatoryAccruedSiteLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:RegulatoryAssetsEnvironmentalRegulatoryAccruedSiteLiabilities nwn:EnvironmentalActivity, us-gaap:RegulatoryAsset

nwn:FrontStreet, us-gaap:EnvironmentalRestorationCosts


Regulatory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0.10.12.0000000000000002e-070.40.40.40.40.40.40.40.40.40.4
Percentage of RegulatoryAssetsEnvironmentalRegulatoryAccruedSiteLiabilities0.10.10.00.30.30.30.30.30.30.30.30.30.3

nwn:RegulatoryAssetsEnvironmentalRegulatoryDeferredCostandInterest dei:LegalEntity, us-gaap:RegulatoryAsset

nwn:RegulatoryAssetsEnvironmentalRegulatoryDeferredCostandInterest

nwn:NorthwestNaturalGasCompany, us-gaap:EnvironmentalRestorationCosts


Regulatory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value50464435423736364336414046
Percentage of RegulatoryAssetsEnvironmentalRegulatoryDeferredCostandInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:RegulatoryAssetsPriorServiceCost us-gaap:RegulatoryAsset

nwn:RegulatoryAssetsPriorServiceCost

us-gaap:PostretirementBenefitCosts


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-31
Value-801000.0-1270000.0-1738000.0-2206000.0
Percentage of RegulatoryAssetsPriorServiceCost100.0100.0100.0100.0

nwn:RemediationNonrecoveryPercentage

nwn:RemediationNonrecoveryPercentage


Remediation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3.33.33.33.30.03320.03320.03320.03320.03320.03320.03320.03320.03320.03320.03320.0332
Percentage of RemediationNonrecoveryPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:RemediationRecoveryPercentage us-gaap:StatementGeographical

nwn:RemediationRecoveryPercentage

stpr:OR


Remediation
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value96.796.796.70.96680.96680.96680.96680.96680.96680.96680.96680.96680.96680.96680.9668
Percentage of RemediationRecoveryPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stpr:WA


Remediation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value3.33.33.33.30.03320.03320.03320.0332
Percentage of RemediationRecoveryPercentage3.43.40.03.43.43.43.43.4

nwn:ReservedSharesDividendReinvestment dei:LegalEntity

nwn:ReservedSharesDividendReinvestment

nwn:NorthwestHoldings


Reserved
Period End2020-12-31
Value271950.0
Percentage of ReservedSharesDividendReinvestment100.0

nwn:ShareBasedCompensationAwardTargetShare us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName

nwn:ShareBasedCompensationAwardTargetShare

nwn:A2018Award, us-gaap:PerformanceShares, nwn:LongTermIncentivePlan


Share
Period End2020-12-312019-12-312018-12-31
Value31825.000
Percentage of ShareBasedCompensationAwardTargetShare100.00.00.0

nwn:ShareBasedCompensationAwardTargetShare us-gaap:AwardType, us-gaap:PlanName

us-gaap:PerformanceShares, nwn:LongTermIncentivePlan


Share
Period End2020-12-312019-12-312018-12-31
Value31825.030234.055793.0
Percentage of ShareBasedCompensationAwardTargetShare100.00.00.0

nwn:ShareBasedCompensationAwardTargetShare us-gaap:Range, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName

srt:Maximum, nwn:A2018Award, us-gaap:PerformanceShares, nwn:LongTermIncentivePlan


Share
Period End2020-12-312019-12-312018-12-31
Value63650.000
Percentage of ShareBasedCompensationAwardTargetShare200.00.00.0

nwn:ShareBasedCompensationAwardTargetShare us-gaap:Range, us-gaap:AwardType, us-gaap:PlanName

srt:Maximum, us-gaap:PerformanceShares, nwn:LongTermIncentivePlan


Share
Period End2020-12-312019-12-312018-12-31
Value63650.060468.0111590.0
Percentage of ShareBasedCompensationAwardTargetShare200.00.00.0

nwn:ShareBasedCompensationAwardTargetShare us-gaap:StatementScenario, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName

nwn:TargetAchieved, nwn:A2020Award, us-gaap:PerformanceShares, nwn:LongTermIncentivePlan


Share
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value31830.056335.031830.031830.031830.0
Percentage of ShareBasedCompensationAwardTargetShare0.00.00.00.00.0

nwn:TargetAchieved, nwn:A2021Award, us-gaap:PerformanceShares, nwn:LongTermIncentivePlan


Share
Period End2021-06-302021-03-31
Value56335.031830.0
Percentage of ShareBasedCompensationAwardTargetShare0.00.0

nwn:SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofSharesAvailableforGrantAnyAwardType us-gaap:PlanName

nwn:SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofSharesAvailableforGrantAnyAwardType

nwn:LongTermIncentivePlan


Sharebased
Period End2020-12-31
Value435760.0
Percentage of SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofSharesAvailableforGrantAnyAwardType100.0

nwn:TargetHedgeAchieved dei:LegalEntity, nwn:GasYear, us-gaap:DerivativeInstrumentRisk

nwn:TargetHedgeAchieved

nwn:NorthwestNaturalGasCompany, nwn:GasYear20182019, nwn:Financial


Target
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value48.00.480.480.480.480.480.480.48
Percentage of TargetHedgeAchieved100.0100.0100.0100.0100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:GasYear20182019, nwn:Physical


Target
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value24.00.240.240.240.240.240.240.24
Percentage of TargetHedgeAchieved50.050.050.050.050.050.050.050.0

nwn:NorthwestNaturalGasCompany, nwn:GasYear20192020, nwn:Financial


Target
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value52.052.052.052.00.520.520.52
Percentage of TargetHedgeAchieved0.00.00.0108.3108.3108.3108.3

nwn:NorthwestNaturalGasCompany, nwn:GasYear20192020, nwn:Physical


Target
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value19.019.019.019.00.190.190.19
Percentage of TargetHedgeAchieved0.00.00.039.639.639.639.6

nwn:TotalCumulativeGasReservesInvestment dei:LegalEntity

nwn:TotalCumulativeGasReservesInvestment

nwn:NorthwestNaturalGasCompany


Total
Period End2020-12-31
Value188
Percentage of TotalCumulativeGasReservesInvestment100.0

nwn:TotalGasReserves

nwn:TotalGasReserves


Total
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value384245495559636873788287919599104
Percentage of TotalGasReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:TotalGasReserves dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Total
Period End2020-12-312019-12-312018-12-312017-12-31
Value45638299
Percentage of TotalGasReserves100.0100.0100.0100.0

nwn:TotalGasReservesInvestment us-gaap:MajorCustomers

nwn:TotalGasReservesInvestment

nwn:JonahEnergyLLC


Total
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value2700000.02800000.03000000.03200000.03400000.03600000.03800000.04000000.04300000.04500000.04800000.05000000.05500000.05600000.05800000.06000000.0
Percentage of TotalGasReservesInvestment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

nwn:TotalPensionAssetInvestmentsNetOfReceivablesAndPayables dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType

nwn:TotalPensionAssetInvestmentsNetOfReceivablesAndPayables

nwn:NorthwestNaturalGasCompany, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Total
Period End2020-12-312019-12-312018-12-312017-12-31
Value39332421
Percentage of TotalPensionAssetInvestmentsNetOfReceivablesAndPayables100.0100.0100.0100.0

nwn:NorthwestNaturalGasCompany, us-gaap:FairValueMeasuredAtNetAssetValuePerShare, us-gaap:PensionPlansDefinedBenefit


Total
Period End2020-12-312019-12-312018-12-312017-12-31
Value334279232266
Percentage of TotalPensionAssetInvestmentsNetOfReceivablesAndPayables856.0843.8931.41252.1

nwn:TotalPensionAssetInvestmentsNetOfReceivablesAndPayables dei:LegalEntity, us-gaap:RetirementPlanType

nwn:NorthwestNaturalGasCompany, us-gaap:PensionPlansDefinedBenefit


Total
Period End2020-12-312019-12-312018-12-312017-12-31
Value373313257287
Percentage of TotalPensionAssetInvestmentsNetOfReceivablesAndPayables956.0943.81031.41352.1

nwn:TotalPensionPlanAssetReceivables dei:LegalEntity, us-gaap:RetirementPlanType

nwn:TotalPensionPlanAssetReceivables

nwn:NorthwestNaturalGasCompany, us-gaap:PensionPlansDefinedBenefit


Total
Period End2020-12-312019-12-312018-12-312017-12-31
Value6429000.03243000.01000.030000.0
Percentage of TotalPensionPlanAssetReceivables100.0100.0100.0100.0

nwn:UnrecordedUnconditionalPurchaseObligationAmountRepresentingInterest dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

nwn:UnrecordedUnconditionalPurchaseObligationAmountRepresentingInterest

nwn:NorthwestNaturalGasCompany, nwn:GasPurchaseAgreements


Unrecorded
Period End2020-12-312019-12-312018-12-31
Value0.0250.4811.314
Percentage of UnrecordedUnconditionalPurchaseObligationAmountRepresentingInterest100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:PipelineCapacityPurchaseAgreements


Unrecorded
Period End2020-12-312019-12-312018-12-31
Value89147201
Percentage of UnrecordedUnconditionalPurchaseObligationAmountRepresentingInterest357212.030688.815313.9

nwn:NorthwestNaturalGasCompany, nwn:PipelineCapacityReleaseAgreements


Unrecorded
Period End2020-12-312019-12-312018-12-31
Value0.1620.840.183
Percentage of UnrecordedUnconditionalPurchaseObligationAmountRepresentingInterest648.0174.613.9

nwn:UnrecordedUnconditionalPurchaseObligationTotalAtPresentValue dei:LegalEntity, us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

nwn:UnrecordedUnconditionalPurchaseObligationTotalAtPresentValue

nwn:NorthwestNaturalGasCompany, nwn:GasPurchaseAgreements


Unrecorded
Period End2020-12-312019-12-312018-12-31
Value8388148
Percentage of UnrecordedUnconditionalPurchaseObligationTotalAtPresentValue100.0100.0100.0

nwn:NorthwestNaturalGasCompany, nwn:PipelineCapacityPurchaseAgreements


Unrecorded
Period End2020-12-312019-12-312018-12-31
Value808731722
Percentage of UnrecordedUnconditionalPurchaseObligationTotalAtPresentValue969.0825.8487.1

nwn:NorthwestNaturalGasCompany, nwn:PipelineCapacityReleaseAgreements


Unrecorded
Period End2020-12-312019-12-312018-12-31
Value25227.649
Percentage of UnrecordedUnconditionalPurchaseObligationTotalAtPresentValue30.225.15.2

nwn:WithAdequateAssuranceCalls dei:LegalEntity, us-gaap:CreditRatingMoodys

nwn:WithAdequateAssuranceCalls

nwn:NorthwestNaturalGasCompany, nwn:Speculative


With
Period End2020-12-312019-12-31
Value51000.0-66000.0
Percentage of WithAdequateAssuranceCalls100.0100.0

nwn:WithoutAdequateAssuranceCalls dei:LegalEntity, us-gaap:CreditRatingMoodys

nwn:WithoutAdequateAssuranceCalls

nwn:NorthwestNaturalGasCompany, nwn:Speculative


Without
Period End2020-12-312019-12-31
Value51000.0-66000.0
Percentage of WithoutAdequateAssuranceCalls100.0100.0

us-gaap:AccountsReceivableGrossCurrent

us-gaap:AccountsReceivableGrossCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value601058840357867294293662531776621
Percentage of AccountsReceivableGrossCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccountsReceivableGrossCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value519680313377662942936625317766
Percentage of AccountsReceivableGrossCurrent85.492.190.978.696.699.099.598.198.999.999.899.5100.0100.0100.0

us-gaap:AccruedEnvironmentalLossContingenciesCurrent

us-gaap:AccruedEnvironmentalLossContingenciesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value22232830343739221730331814161910
Percentage of AccruedEnvironmentalLossContingenciesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedEnvironmentalLossContingenciesCurrent dei:LegalEntity

nwn:NorthwestNaturalGasCompany


Accrued
Period End2020-12-312019-12-312018-12-312017-12-31
Value28393319
Percentage of AccruedEnvironmentalLossContingenciesCurrent100.0100.0100.0100.0

us-gaap:AccruedEnvironmentalLossContingenciesCurrent dei:LegalEntity, nwn:EnvironmentalActivity

nwn:NorthwestNaturalGasCompany, nwn:FrontStreet


Accrued
Period End2020-12-312019-12-312018-12-312017-12-31
Value3.81610111.009
Percentage of AccruedEnvironmentalLossContingenciesCurrent13.527.734.45.3

nwn:NorthwestNaturalGasCompany, nwn:GascoSiltronicSediments


Accrued
Period End2020-12-312019-12-312018-12-312017-12-31
Value7.596115.1172.683
Percentage of AccruedEnvironmentalLossContingenciesCurrent26.929.715.514.1

nwn:NorthwestNaturalGasCompany, nwn:GascoSiltronicUpland


Accrued
Period End2020-12-312019-12-312018-12-312017-12-31
Value14141313
Percentage of AccruedEnvironmentalLossContingenciesCurrent52.736.242.270.3

nwn:NorthwestNaturalGasCompany, nwn:PortlandHarborOther


Accrued
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.9422.5432.61.949
Percentage of AccruedEnvironmentalLossContingenciesCurrent6.96.57.910.2

us-gaap:AccruedEnvironmentalLossContingenciesCurrent us-gaap:EnvironmentalRemediationSite

nwn:FrontStreet


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1.2191.2583.816101010106.0091.05111116.0110.9060.7641.0090.846
Percentage of AccruedEnvironmen