AVA


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

Table of contents



us-gaap:CommonStockValue
us-gaap:SubsidiarySaleOfStock
us-gaap:CommonStockSharesAuthorized

us-gaap:PreferredStockSharesAuthorized

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:CostsAndExpenses

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments

us-gaap:IncomeTaxExpenseBenefit
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

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

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:ProfitLoss

us-gaap:RegulatedOperatingRevenue
us-gaap:MajorCustomers
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments

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

us-gaap:UnregulatedOperatingRevenue

us-gaap:Assets
us-gaap:ConsolidatedEntities, us-gaap:CounterpartyName, us-gaap:OtherCommitments
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:CounterpartyName

us-gaap:Liabilities

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:StockholdersEquity

us-gaap:AssetsCurrent

us-gaap:CashAndCashEquivalentsAtCarryingValue
us-gaap:FairValueByAssetClass

us-gaap:InventoryNet

us-gaap:InventoryRawMaterialsAndSupplies

us-gaap:OtherAssetsCurrent

us-gaap:PropertyPlantAndEquipmentGross
us-gaap:PublicUtility, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:Goodwill
us-gaap:StatementBusinessSegments

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OtherAssetsNoncurrent

us-gaap:EquitySecuritiesFvNi

us-gaap:AccountsPayableCurrent

us-gaap:AccruedLiabilitiesCurrent

us-gaap:LiabilitiesCurrent

us-gaap:LongTermDebtCurrent

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OtherLiabilitiesCurrent
us-gaap:LongtermDebtType
us-gaap:LongTermDebt

us-gaap:LongTermDebtNoncurrent

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
us-gaap:RetirementPlanType

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:OperatingLeaseLiability

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:StockholdersEquity

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueNewIssues
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:AmortizationOfFinancingCosts

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DepreciationDepletionAndAmortization

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInInventories

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:ProfitLoss

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:PaymentsOfDividends

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:DeferredTaxLiabilities

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:ProceedsFromRepaymentsOfShortTermDebt

ava:AdjustmentInDecouplingRegulatoryDeferral
us-gaap:UnusualOrInfrequentItem
ava:DeferredIncrementalBadDebtExpense

ava:DepreciationAndAmortizationExpense
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

ava:EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalAmount

ava:EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalPercent
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
ava:EnergyCommodityDerivativeExpectedToBeSettleYearFive
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
ava:EnergyCommodityDerivativeExpectedToBeSettleYearFour
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
ava:EnergyCommodityDerivativeExpectedToBeSettleYearOne
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
ava:EnergyCommodityDerivativeExpectedToBeSettleYearThree
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation
ava:EnergyCommodityDerivativeExpectedToBeSettleYearTwo
us-gaap:FairValueByFairValueHierarchyLevel
ava:FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssets
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass

ava:IncomeTaxReconciliationSettlementOfShareBasedCompensationAmount

ava:IncomeTaxReconciliationSettlementOfShareBasedCompensationPercent

ava:InterestExpenseExcludingInterestExpenseToRelatedParty

ava:InterestExpenseIncludingAffiliatedTrusts
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
ava:LitigationSettlementIncreasedPotentialClaim
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
ava:OtherComprehensiveIncomeLossAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostAdjustmentDueEffectsOfRegulation

ava:OtherOperatingExpenses
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

ava:OtherRegulatoryAssetsAndLiabilitiesDeferredDebitsAndCredits
us-gaap:DerivativeInstrumentRisk
ava:PaymentsForProceedsFromDerivativeInstrumentOperatingActivities

ava:PaymentsToAcquireEquityAndPropertyInvestments

ava:PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

ava:PercentageOfNonserviceRelatedNetPeriodicBenefitCostsCapitalizedToRegulatoryAssets

ava:PercentageOfNonserviceRelatedNetPeriodicBenefitCostsRecordedToOtherExpense

ava:PercentageOfServiceRelatedNetPeriodicBenefitCostsCapitalizedToUtilityProperty

ava:PercentageOfServiceRelatedNetPeriodicBenefitCostsRecordedToOperatingExpenses

ava:PowerAndNaturalGasCostAmortizationDeferralsNet

ava:PublicUtilityOperatingExpensesExciseTaxesCollected

ava:RegulatedRevenuesExcludingAlternativeRevenuePrograms

ava:RevenueFromAlternativeRevenuePrograms

ava:TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferences

ava:TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferencesPercent

ava:UtilitiesOperatingExpenseDeferralsForProductsAndServices
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:CommonStockDividendsPerShareCashPaid
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:DepreciationAndAmortization
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:Position, us-gaap:ValuationTechnique
us-gaap:DerivativeNonmonetaryNotionalAmountEnergyMeasure
us-gaap:StatementEquityComponents
us-gaap:DividendsCommonStockCash

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments

us-gaap:EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes

us-gaap:EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass

us-gaap:GainLossOnSaleOfInvestments

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationOtherAdjustments

us-gaap:IncomeTaxReconciliationPriorYearIncomeTaxes

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes

us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable

us-gaap:IncreaseDecreaseInAccruedIncomeTaxesPayable
us-gaap:SubsequentEventType
us-gaap:IncreaseDecreaseInDeferredIncomeTaxes

us-gaap:IncreaseDecreaseInDepositOtherAssets

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInOtherOperatingAssets

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:InterestExpenseRelatedParty
us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType
us-gaap:LitigationSettlementAmountAwardedToOtherParty
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsToAcquireNotesReceivable

us-gaap:PensionAndOtherPostretirementBenefitExpense

us-gaap:PensionContributions

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromSaleOfEquityMethodInvestments

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:StatementBusinessSegments
us-gaap:RepaymentsOfDebt

us-gaap:UtilitiesOperatingExpenseDepreciationAndAmortization

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses

us-gaap:UtilitiesOperatingExpenseProductsAndServices

us-gaap:UtilitiesOperatingExpenseTaxes
us-gaap:RetirementPlanType
ava:AccumulatedComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansRegulatoryAssetInNetPeriodicBenefitCostNetOfTax
us-gaap:RetirementPlanType
ava:AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeRegulatoryAssetNetOfTax

ava:AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossTax

ava:AmountAvailableForDividendDistributionWithoutAffectingCovenants
us-gaap:LongtermDebtType, us-gaap:StatementBusinessSegments
ava:AmountOfFirstMortgageBondsThatCouldBeIssued

ava:AssetsHeldForSale
us-gaap:Range, us-gaap:AwardType
ava:CommonStockIssuedRangePercentOfPerformanceSharesGranted
us-gaap:SubsidiarySaleOfStock
ava:CommonStockSharesAuthorizedUnderSalesAgencyAgreementsRemainingSharesAuthorizedToSell
us-gaap:DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensation
ava:DeferredCompensationAssetsAndLiabilities
us-gaap:UnusualOrInfrequentItem
ava:DeferredNetBenefitToCustomers

ava:DeferredTaxAssetsRegulatoryLiabilities
us-gaap:StatementBusinessSegments
ava:LineofCreditFacilityCovenantTermsMaximumDebttoEquityRatio

ava:LongTermDebtBeforeCurrentPortionAndBondsHeldByCompany

ava:NonRegulatedProperty
us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency
ava:NumberOfResidentialCommercialAndOtherStructuresImpacted
us-gaap:SubsidiarySaleOfStock
ava:NumberOfShareRequestedToRegulatoryAuthority
us-gaap:StatementEquityComponents
ava:NumberOfSharesAuthorizedToIssueByRegulatoryAuthority

ava:PendingRegulatoryTreatmentLiability
us-gaap:RegulatoryLiability

ava:PropertyPlantAndEquipmentTotal

ava:RegulatoryAssetEarningReturn
us-gaap:RegulatoryAsset

ava:RegulatoryLiabilityEarningReturn
us-gaap:RegulatoryLiability
us-gaap:StatementBusinessSegments
ava:RegulatoryRestrictionsMaximumDebttoEquity

ava:RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided
us-gaap:RegulatoryLiability
us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency
ava:RoadFireCoveredArea

ava:SecuredandUnsecuredDebt
us-gaap:TaxCreditCarryforward
ava:TaxCreditCarryforwardsNetofValuationAllowance
us-gaap:CounterpartyName
ava:VariableInterestEntityRemainingInvestmentCommitmentAmount
us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency
ava:WildfireCoveredArea

us-gaap:AccountsNotesAndLoansReceivableNetCurrent

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

us-gaap:AccruedVacationCurrent

us-gaap:AccumulatedDeferredInvestmentTaxCredit

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax
us-gaap:RetirementPlanType
us-gaap:DerivativeInstrumentRisk
us-gaap:AdditionalCollateralAggregateFairValue

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AmountOfRegulatoryCostsNotYetApproved
us-gaap:RegulatoryAsset

us-gaap:AssetRetirementObligation
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:AssetsFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
us-gaap:DerivativeInstrumentRisk
us-gaap:CollateralAlreadyPostedAggregateFairValue
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument
us-gaap:DebtInstrumentFaceAmount
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTerms

us-gaap:DebtInstrumentUnamortizedDiscount

us-gaap:DeferredCompensationPlanAssets
us-gaap:AwardType
us-gaap:DeferredCompensationShareBasedArrangementsLiabilityCurrent

us-gaap:DeferredGasCost

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsTaxCreditCarryforwards

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment

us-gaap:DeferredTaxLiabilitiesRegulatoryAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
ava:DefinedBenefitPlanBenefitObligationbyParticipantType, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan
ava:SurgicalMedicals, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:StatementScenario, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
ava:SurgicalMedicals, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeAssets
us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:DerivativeAssetsLiabilitiesAtFairValueNet
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeCollateralRightToReclaimCash

us-gaap:DerivativeFairValueAmountOffsetAgainstCollateralNet
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeFairValueOfDerivativeAsset
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:Position, us-gaap:ValuationTechnique
us-gaap:DerivativeForwardPrice
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilities
us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:DerivativeLiabilitiesNoncurrent
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeNetLiabilityPositionAggregateFairValue
us-gaap:Currency, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeNotionalAmount
us-gaap:DebtInstrument, us-gaap:DerivativeInstrumentRisk
us-gaap:AwardType
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:EnergyMarketingContractLiabilitiesCurrent

us-gaap:EnergyRelatedInventoryGasStoredUnderground

us-gaap:EquityMethodInvestments
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass

us-gaap:FinanceLeaseLiability
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis, us-gaap:LongtermDebtType, us-gaap:StatementBusinessSegments

us-gaap:FinanceLeaseLiabilityCurrent

us-gaap:FinanceLeaseLiabilityNoncurrent

us-gaap:FinanceLeaseLiabilityPaymentsDue

us-gaap:FinanceLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount

us-gaap:FinanceLeaseRightOfUseAsset

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

us-gaap:IncomeTaxesReceivable

us-gaap:InterestPayableCurrent

us-gaap:InvestmentsAndOtherNoncurrentAssets
us-gaap:StatementBusinessSegments
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:InvestmentsFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:JointlyOwnedUtilityPlant
us-gaap:JointlyOwnedUtilityPlantGrossOwnershipAmountOfPlantInService
us-gaap:JointlyOwnedUtilityPlant
us-gaap:JointlyOwnedUtilityPlantOwnershipAmountOfPlantAccumulatedDepreciation

us-gaap:JointlyOwnedUtilityPlantProportionateOwnershipShare

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
us-gaap:DerivativeInstrumentRisk
us-gaap:LettersOfCreditOutstandingAmount
us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:LineOfCreditFacilityInterestRateAtPeriodEnd
us-gaap:DebtInstrument, us-gaap:ShortTermDebtType
us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:StatementBusinessSegments
us-gaap:LinesOfCreditCurrent
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtFairValue
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:LongtermDebtType
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
us-gaap:LongtermDebtType
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
us-gaap:LongtermDebtType
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
us-gaap:LongtermDebtType
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
us-gaap:Range, us-gaap:FairValueByMeasurementBasis, us-gaap:LongtermDebtType, us-gaap:MeasurementInputType
us-gaap:LongTermDebtMeasurementInput

us-gaap:NotesAndLoansReceivableNetNoncurrent

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent

us-gaap:OtherAccruedLiabilitiesNoncurrent

us-gaap:OtherAssetsMiscellaneousCurrent

us-gaap:OtherInventory

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent

us-gaap:PrepaidExpenseCurrent

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation
us-gaap:StatementBusinessSegments
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentCommon

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress
us-gaap:PublicUtility, us-gaap:StatementBusinessSegments
us-gaap:PublicUtility, us-gaap:StatementBusinessSegments
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDistribution
us-gaap:PublicUtility, us-gaap:StatementBusinessSegments
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentNet
us-gaap:PublicUtility, us-gaap:StatementBusinessSegments
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentPlantInService
us-gaap:PublicUtility, us-gaap:StatementBusinessSegments
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentTransmission
us-gaap:RegulatoryAsset, us-gaap:StatutoryAccountingPracticesByJurisdiction
us-gaap:RegulatoryAssets

us-gaap:RegulatoryAssetsCurrent
us-gaap:RegulatoryAsset

us-gaap:RegulatoryAssetsNoncurrent
us-gaap:RegulatoryAsset
us-gaap:RegulatoryLiability, us-gaap:StatutoryAccountingPracticesByJurisdiction
us-gaap:RegulatoryLiabilities

us-gaap:RegulatoryLiabilityCurrent
us-gaap:RegulatoryLiability

us-gaap:RegulatoryLiabilityNoncurrent
us-gaap:RegulatoryLiability

us-gaap:RemainingAmountsOfRegulatoryAssetsForWhichNoReturnOnInvestmentDuringRecoveryPeriodIsProvided
us-gaap:RegulatoryAsset

us-gaap:RetainedEarningsAppropriated

us-gaap:RevenueRemainingPerformanceObligation

us-gaap:SecuredDebt
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:ShortTermBorrowings
us-gaap:TaxCreditCarryforward
us-gaap:TaxCreditCarryforwardAmount
us-gaap:TaxCreditCarryforward
us-gaap:TaxCreditCarryforwardValuationAllowance

us-gaap:UnamortizedDebtIssuanceExpense

us-gaap:UnbilledReceivablesCurrent

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary
us-gaap:PublicUtility

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary
us-gaap:PublicUtility

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary
us-gaap:PublicUtility

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary
us-gaap:PublicUtility

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary
us-gaap:PublicUtility

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
us-gaap:PublicUtility

us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears
us-gaap:PublicUtility
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:UnsecuredDebt
us-gaap:ConsolidatedEntities, us-gaap:TypeOfArrangement
us-gaap:VariableInterestEntityEntityMaximumLossExposureAmount

Plots across concepts


IncomeStatement
Other Comprehensive Income Loss Net Of Tax
Expenses
Income Tax Expense Benefit
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
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
Share Based Compensation
NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInFinancingActivities
Proceeds From Payments For Other Financing Activities
Shares
Weighted Average Number Of Shares Outstanding Basic
OperatingLeaseLiability
Operating Lease Liability Current
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Payments Due Next Twelve Months

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:CommonStockValue ███▇▇▇▇▆▆▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▄▄▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁1303.4111285.9991286.0681265.1911234.9011209.3121210.7411186.9251157.0241140.2421136.4911135.5431134.3041131.5491133.4481077.2151075.6671073.0981075.2811073.4811052.191032.0231004.3361002.7161001.253998.975999.961007.764885.741899.037896.993898.199895.255891.759889.237887.53861.053857.747855.188848.709842.054833.617827.592NANANA
 us-gaap:CommonStockSharesAuthorized us-gaap:SubsidiarySaleOfStock ava:SalesAgencyAgreementNA3.23.23.23.2NA4.64.64.63.83.83.83.83.83.83.83.83.8NA3.83.83.8NANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PreferredStockSharesAuthorized NANA10.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁69.53469.506NA68.33767.58967.38167.05966.35165.96365.94165.84666.02665.98365.93165.30864.89264.55364.46964.6264.32563.78362.90762.75862.68862.662.88962.67164.24460.46360.16860.08760.03259.96259.89859.82659.12358.92458.9558.58358.23258.14357.41457.12655.80155.23155.115
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁69.40469.293NA68.19467.48167.23966.92966.26565.89465.73365.68865.68865.67765.63964.80964.41264.40164.36264.18563.85763.38662.60562.30862.29962.28162.31862.2963.93460.18460.12260.03759.99459.93759.86659.77459.04758.70258.58158.30458.05757.78757.34256.83555.61655.03154.869
us-gaap:EarningsPerShareBasic ▂▅▄▁▂▄▄▁▂█▄▁▂▄▂▁▂▅▃▁▂▄▃▂▂▄▃▁█▄▃▁▂▄▂▁▂▃▂▁▂▄▃▂▃▃0.20.980.85999999999999990.070.260.720.75999999999999980.080.381.760.70000000000000020.150.390.840.429999999999999940.070.340.970.63000000000000010.190.430.90.61999999999999990.210.410.750.520.161.680.810.530.190.430.710.260.10.310.660.419999999999999930.180.40.730.449999999999999960.220.460.53
us-gaap:EarningsPerShareDiluted ▂▅▄▁▂▄▄▁▂█▄▁▂▄▂▁▂▅▃▁▂▄▃▂▂▄▃▁█▄▃▁▂▄▂▁▂▃▂▁▂▄▃▂▃▃0.20.980.85999999999999990.070.260.720.760.080.381.760.70.150.390.830.420.070.340.960.620.190.430.890.610.210.40.740.510.161.670.810.530.190.430.710.260.10.310.650.420.180.390.730.450.220.460.52
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 Operating Margin us-gaap:ConsolidationItems,us-gaap:ProductOrService us-gaap:OperatingSegments,ava:UtilityRevenue▂█▆▁▁▇▆▂▂298.107412.681380.154272.379278.337389.407363.283282.721298.551NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Operating Margin us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ava:UtilityRevenue,ava:AlaskaElectricLightPower▅█▇▂▄▇▄▁▂10.54712.82111.7958.8159.99712.2029.8517.798.743NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 Operating Margin us-gaap:ConsolidationItems,us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,ava:UtilityRevenue,ava:AvistaUtilities▂█▆▁▁▇▆▂▂287.56399.86368.359263.564268.34377.205353.432274.931289.808NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:ComprehensiveIncomeNetOfTax NANA53.9715.09617.67348.62947.95.25225.48115.95447.19710.32325.78155.09426.5084.63321.95462.29940.12212.37427.39454.82339.02213.25725.49146.69528.2310.563101.78649.39333.69511.20124.60842.45414.0556.04718.44638.59923.30510.82523.06141.72223.64512.38225.57628.846
us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest ▂▅▄▁▂▄▄▁▂█▄▁▂▄▂▁▂▅▃▁▂▄▃▂▂▄▂▁▇▄▃▁▂▃▂▁▂▃▂▁▂▃▂▂▂▃14.38268.33253.9715.09617.67348.62947.95.25225.177116.04147.22310.33325.84855.1626.5454.6421.90562.3240.13412.40127.42754.83939.03913.28925.51946.70828.25310.583101.49749.87533.56111.71924.68143.21414.296.22318.838.42424.67311.7623.58842.20724.16613.3726.08329.353
us-gaap:CostsAndExpenses ▂▄▃▁▁▄▃▁▂▅▃▂▂▄▄▂▂▅▄▂▂▄▄▃▃▆▆▂▁█▇▄▃█▇▄▃▇▇▄▄█▄▅▄█266.503310.975293.34244.148243.666308.037291.252253.527261.044329.41295.037259.569266.019315.155315.878266.054258.404321.084319.59263.755257.247312.088316.938277.737279.972356.915345.093268.796249.849397.822381.356300.606294.306397.844369.481310.633295.286373.535378.532308.832305.033391.761311.549329.428298.984388.591
us-gaap:IncomeLossFromContinuingOperations ▂▅▄▁▂▄▄▁▂█▄▁▂▄▂▁▂▅▃▁▂▄▃▂▂▄▃▁▃▄▃▁▂▃14.07468.01758.7354.87617.45348.42450.7765.0925.319115.79445.84310.11925.57754.8927.5784.45121.77162.11640.09112.23427.25456.05233.85912.72225.0546.44930.58110.50631.25447.47630.3918.4524.21241.22NANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments ▂▅▄▁▁▄▃▁▂█▃▁▂▄▄▁▂▅▄▂▃▅▃▂▃▄▃▂▃▅▃▂▃▄▂▁▂▄▃▂▃▄▃▂▃▃16.47280.18164.3145.7359.53456.95654.0054.95923.275145.89854.46211.67730.85365.66658.8259.61134.77395.48163.52819.86743.99788.0153.94718.86940.09472.70951.5717.82747.96177.15748.65517.3941.14268.33724.2487.5728.89259.35141.66615.35437.11166.0438.67518.36441.88247.184
us-gaap:IncomeTaxExpenseBenefit ▃▄▃▂▁▄▃▂▂▇▄▃▃▄█▃▅█▆▄▅█▆▃▅▇▆▄▅▇▅▃▅▇▄▃▄▆▅▃▅▆▄▃▅▅2.39812.1645.5790.859-7.9198.5323.229-0.131-1.74130.0178.5931.5485.20910.7131.215.15313.05133.34423.4257.60616.7131.94220.0716.11515.01626.24720.9667.30116.69128.17617.1235.45915.41225.2368.1551.60810.3621.13815.6953.71713.58323.63712.4255.0315.83517.867
us-gaap:NetIncomeLoss ▂▅▄▁▂▄▄▁▂█▄▁▂▄▂▁▂▅▃▁▂▄▃▂▂▄▃▁▇▄▃▁▂▃▂▁▂▃▂▁▂▃▂▁▂▃14.07468.01758.7354.87617.45348.42450.7765.0925.319115.79445.84310.11925.57754.8927.5784.45121.77162.11640.09112.23427.25456.05238.52113.01125.24646.44932.2210.451100.87148.49931.66611.41325.65742.34115.8585.78618.17838.38824.60310.70223.00141.91825.72912.34625.5428.81
us-gaap:OperatingIncomeLoss ▁▇▆▁▂▅▅▁▂▄▅▂▃▆▅▁▃█▅▂▄▇▄▂▃▆▄▁▄▆▄▂▃▆▂▁▃▅▄▂▃▆▄▂▄▄31.752101.89587.08328.49834.92682.19373.30730.24339.76867.07177.18436.44453.27994.20681.98431.04256.097115.38682.53339.59461.591106.08570.36735.91257.3689.57566.75332.76262.73193.1466.3235.26957.74285.06241.04729.99948.29978.72260.39534.87855.52484.82562.87137.74461.74967.824
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▆▆▁▆▆▆▃▆▆▆▇▆▆▆▅▆▆▆▆▆▆▅▆▆▆▆▂▆▇▇█▆▅▆▄▆▆▆▅▆▆0.3080.315-4.7640.220.220.205-2.8760.1620.1610.161.3540.2040.2040.204-1.070.1820.1830.1830.0310.140.14-1.2290.5010.2460.2450.246-3.990.1120.9150.8942.029-0.212-1.0490.113-1.8030.2610.2680.211-1.2980.1230.06NANANANANA
us-gaap:OtherNonoperatingIncomeExpense █▅▆▂▃▃▆▃▇▄▄▂▄▁▃▄▄▅▅▄▅▄▅▄▄▄▅▄▅▄▄▄▄▄█▁▃▃▃▂▃▃▁▃▃▂10.0413.6846.836-2.1680.5310.3825.933-0.188.2680.9072.493-1.3791.907-4.4790.4651.8411.6563.1013.0531.5623.0412.4223.112.1231.8362.2313.0832.6083.0552.5511.1120.9842.4362.14510.131-3.809-0.678-0.619-1.124-1.626-0.803-0.632-4.482-0.807-0.969-1.699
us-gaap:ProfitLoss NANA58.7354.87617.45348.42450.7765.0925.016115.88145.86910.12925.64454.95627.6154.45821.72262.13740.10312.26127.28756.06838.53813.04325.27446.46232.24310.471100.58248.98131.53211.93125.7343.10116.0935.96218.53238.21325.97111.63723.52842.40326.2513.33426.04729.317
us-gaap:RegulatedOperatingRevenue ▂█▆▁▁▇▆▂▂▇▆▂▃▇298.107412.681380.154272.379278.337389.407363.283282.721298.551388.583365.325289.119312.704402.417NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:CommercialElectric87.035NANANA74.514NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:CommercialandGovernmentalElectricNA81.05683.37184.82474.51485.04885.49286.20981.21284.06683.27587.2983.00386.953NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:Electric▅█▇▄▁▇▇▃▁216.664238.484231.418214.339192.009234.509233.54207.807194.652NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:IndustrialElectric▄▃▁▅▁▁▂▅▃▂▂█▅▁27.42926.6125.10428.47224.81624.71125.85628.45326.24525.24825.93630.80627.98525.119NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:OtherElectric▅▅▄▃▁▄█▄▂▇██▂▅6.5326.145.9964.5513.4155.2898.5365.864.3798.1948.598.5643.9196.291NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:PublicStreetandHighwayLightingElectric▅▄▄▄▄▁▂▄▆▇█▅▇▅1.9281.9121.8961.911.9051.8441.8661.9151.9561.9661.9871.9261.9621.927NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:ResidentialElectric▃█▆▃▂▇▆▂▁█▅▂▁█88.939119.271110.93688.64482.95113.843107.0781.31276.61121.244101.53885.45778.973121.291NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:RetailElectric▄█▇▄▁▇▇▃▁205.331228.849221.307203.85184.185225.446220.284197.889186.023NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers ava:TransmissionElectric▅▁▃█▄▂▅▃▃▆▅▅4.8013.4954.1155.9384.4093.7744.724.0584.255.1525.0314.832NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:CommercialAndGovernmentalNaturalGas,ava:AvistaUtilitiesNA39.775NA9.34NA39.401NA10.093NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:CommercialElectric,ava:AlaskaElectricLightPower6.177NANANA5.729NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:CommercialElectric,ava:AvistaUtilities80.858NANANA68.785NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:CommercialNaturalGas,ava:AvistaUtilities15.598NANANA14.14239.40132.11210.09313.36936.59527.8649.43714.66837.373NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:CommercialandGovernmentalElectric,ava:AlaskaElectricLightPowerNA4.7726.2755.5825.7296.1994.8764.8574.8374.8214.8586.5466.5418.044NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:CommercialandGovernmentalElectric,ava:AvistaUtilitiesNA76.28477.09679.24268.78578.84980.61681.35276.37579.24578.41780.74476.46278.909NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:Electric,ava:AlaskaElectricLightPower▅█▇▃▄▇▄▁▂10.48712.77911.7248.7979.97812.1269.7367.6878.62NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:Electric,ava:AvistaUtilities▅█▇▅▁▇█▄▂206.177225.705219.694205.542182.031222.383223.804200.12186.032NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:IndustrialElectric,ava:AlaskaElectricLightPowerNA1.899NANA0.00.00.00.00.00.00.00.00.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:IndustrialElectric,ava:AvistaUtilities▄▁▁▅▁▁▂▅▃▂▂█▅▁27.42924.71125.10428.47224.81624.71125.85628.45326.24525.24825.93630.80627.98525.119NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:IndustrialandInterruptibleNaturalGas,ava:AvistaUtilities▆█▆▄▄█▄▁▂▅▁▁▂▅1.8192.2241.8521.5381.5432.1941.5331.01.1031.6270.9861.0061.0781.683NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:NaturalGas,ava:AvistaUtilities▂█▆▁▂█▆▁▂54.499132.908110.98134.49453.374129.245107.88334.41445.573NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:OtherElectric,ava:AvistaUtilities▅▅▄▃▁▄█▄▂▇██▂▅6.5326.145.9964.5513.4155.2898.5365.864.3798.1948.598.5643.9196.291NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:OtherNaturalGas,ava:AvistaUtilities█▁▁▁▁▁▁▁▁▁▁▁▁▁1.4061.1251.1261.1251.1251.1251.1251.1251.1251.1251.1251.1251.1251.125NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:PublicStreetandHighwayLightingElectric,ava:AlaskaElectricLightPower▁▂▇▆▁▃▆▆▁▄▆▆▄█0.0590.060.0670.0650.0590.0610.0660.0660.0590.0630.0660.0660.0630.068NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:PublicStreetandHighwayLightingElectric,ava:AvistaUtilities▅▅▃▄▄▁▂▄▇▇█▅▇▅1.8691.8521.8291.8451.8461.7831.81.8491.8971.9031.9211.861.8991.859NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:ResidentialElectric,ava:AlaskaElectricLightPower▄▇▆▂▄▇▅▁▃▇▅▁▄█4.2516.0485.3823.154.195.8664.7942.7643.7245.8524.8262.9874.1556.538NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:ResidentialElectric,ava:AvistaUtilities▃█▆▃▂▇▆▂▁█▅▃▁█84.688113.223105.55485.49478.76107.977102.27678.54872.886115.39296.71282.4774.818114.753NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:ResidentialNaturalGas,ava:AvistaUtilities▂█▇▁▃█▆▁▂▇▆▁▂▇33.70387.50173.77920.83534.82684.17370.88720.27127.93777.33663.67219.24730.76780.653NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:RetailElectric,ava:AlaskaElectricLightPower▅█▇▃▄▇▄▁▂10.48712.77911.7248.7979.97812.1269.7367.6878.62NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:RetailElectric,ava:AvistaUtilities▄█▇▄▁█▇▄▂194.844216.07209.583195.053174.207213.32210.548190.202177.403NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:RetailNaturalGas,ava:AvistaUtilities▂█▆▁▂█▆▁▂51.12129.5107.68531.71350.511125.768104.53231.36442.409NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:TransmissionElectric,ava:AvistaUtilities▅▁▃█▄▂▅▃▃▆▅▅4.8013.4954.1155.9384.4093.7744.724.0584.255.1525.0314.832NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:TransmissionNaturalGas,ava:AvistaUtilitiesNANANA1.656NANANA1.925NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers,us-gaap:StatementBusinessSegments ava:TransportationNaturalGas,ava:AvistaUtilities▁█1.9732.283NANA1.7382.3522.2261.9252.0392.4842.3082.0072.2212.567NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:Revenues ▂▅▄▁▁▅▄▁▂▅▄▂▂▅▅▂▂▆▅▂▂▆▅▂▃▇▅▂▂█▇▃▄█▅▃▃▇▆▃▄█▄▄▄▇298.255412.87380.423272.646278.592390.23364.559283.77300.812396.481372.221296.013319.298409.361397.862297.096314.501436.47402.123303.349318.838418.173387.305313.649337.332446.49411.846301.558312.58490.962447.676335.875352.048482.906410.528340.632343.585452.257438.927343.71360.557476.586374.42367.172360.733456.415
us-gaap:UnregulatedOperatingRevenue ▁▁▁▁▁▂▂▂▃█▇▇▇▇0.1480.1890.2690.2670.2550.8231.2761.0492.2617.8986.8966.8946.5946.944NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:Assets █▇▇▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▅▄▄▄▄▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁6646.3016399.4966402.0976283.1316302.6246173.9996082.4565964.7835877.9285889.9835782.5765557.3985501.785485.1835514.7325452.2325373.0045340.3595309.7555215.1065069.0214956.0134906.6494739.2064679.9894689.0294712.3314336.3464202.134316.0784361.9234402.0024347.7964332.1384313.1794190.2564216.3554254.0044214.5313968.5863842.8963823.7853940.095NANANA
us-gaap:Liabilities █▇▇▇▇▇▆▆▆▆▆▅▅▅▅▅▅▅▅▄▄▄▄▃▃▃▃▂▂▂▂▃▂▂▂▂▂▂▂▁▁▁▂4576.3354330.9064372.3714300.284327.5864214.9044143.1724071.2153993.8944021.7614008.5313807.0473739.0733726.6123784.2483781.2863686.113654.9133661.2793586.5823452.2843366.7453378.3623231.0093165.9843182.273229.0892844.5892792.5852949.0053027.7673083.2153025.5583019.433031.1062906.3482946.5172988.72976.8472746.1282622.9412621.1612768.189NANANA
us-gaap:LiabilitiesAndStockholdersEquity █▇▇▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▅▄▄▄▄▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁6646.3016399.4966402.0976283.1316302.6246173.9996082.4565964.7835877.9285889.9835782.5765557.3985501.785485.1835514.7325452.2325373.0045340.3595309.7555215.1065069.0214956.0134906.6494739.2064679.9894689.0294712.3314336.3464202.134316.0784361.9234402.0024347.7964332.1384313.1794190.2564216.3554254.0044214.5313968.5863842.8963823.7853940.095NANANA
us-gaap:StockholdersEquity ███▇▇▇▇▇▇▇▆▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁2069.9662068.592029.7261982.8511975.0381959.0951939.2841893.5681884.0341867.311773.221749.5521762.4581758.3891729.8281670.9461686.8941685.4461648.4761628.5241616.7371589.2681528.2871508.1971514.0051506.7591483.2421491.7571409.5451351.1131318.2671310.4571314.4211304.7381277.1351277.1821216.4141207.6711185.8751170.3881167.5881160.3791125.7841105.8711085.21NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AssetsCurrent ▃▃▃▂▃▂▂▁▁▃▃▁▁▂▃▂▂▃▃▂▁▂▂▁▂▂▄▁▅▆▇▆▅▆▆▆▇██▇▅▅▇361.954350.082343.977299.662352.507274.238305.129247.646269.767364.803346.923245.512259.985309.747337.534316.634320.736357.292351.341284.375268.719279.224306.046257.98289.33310.496395.347265.204442.267504.386549.679485.844468.693507.014505.794516.316555.365607.201614.556548.253455.348465.159579.565NANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▂▂▁▄▅▁▁▁▁▁▁▁▂▂▁▁▁▂▁▁▁▁▁▁▁▂▂▁█▄▄▄▄▄▃▄▄▃▃▃▃▃▃▃▂▂39.02721.64714.19684.747116.39418.9199.89614.45417.23114.86114.65621.1735.33326.27316.17214.71613.4126.1798.5077.08413.52212.76710.4849.31416.24222.08122.14310.391207.96790.17282.57491.97985.41189.19775.46482.95293.41672.70374.66278.10369.91661.83769.41356.68238.5339.603
us-gaap:InventoryNet █▅▆▆▆▅▆▆▆▅▅▅▅▄▅▆▅▃▄▅▄▃▄▅▄▃▆▆▄▁▃▅▃▁▃▄▄▂▄▆▃▂▃82.77863.1667.45169.02667.33356.68166.58367.73267.65961.35463.88162.76656.90149.25958.07565.96161.18747.18453.31458.0851.63943.88554.14859.73550.87343.78566.35669.94149.43732.80444.94656.84345.32230.31847.45551.06651.13736.35452.00664.87847.68338.39748.53NANANA
us-gaap:InventoryRawMaterialsAndSupplies ██▇▇▆▆▆▆▆▆▆▅▅▅▄▄▄▅▄▄▄▄▃▃▃▃▂▂▂▂▂▂▂▁▁57.06856.36853.25850.59948.86749.00747.40246.72146.88647.70547.40345.16944.33543.20241.49341.51841.49242.19840.739.48738.03738.71837.10134.95735.05633.27132.48331.22631.01629.15828.74729.33429.29726.51126.058NANANA24.148NANANA24.998NANANA
us-gaap:OtherAssetsCurrent ███▂▃▂▃▃▂▅▅▂▁▄▄▄▆▅▄▃▃▃▂▃▃▃▄▃▃▄▅▃▂▃▁▂▂▂▄▂▂▂▁83.1482.92284.88526.57742.36230.32840.14236.99330.59960.94854.0135.15922.51644.60852.31846.24662.40358.71849.62535.87939.78637.16729.93739.08143.42843.63945.07138.5238.11444.52657.70639.72134.64739.10324.64131.78528.57126.94349.22534.5627.46829.75721.831NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:PropertyPlantAndEquipmentGross ███▇▇▇▇▇▇▆▆▆▆▆▆▅▅▅▅▅▅▄▄▄▄▄▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁7165.0137059.3376985.5646886.7696809.1566710.866627.9346520.836454.6346368.6676370.5666240.616151.4616047.4016011.1475881.3125786.2335702.0075656.9735552.5415491.8295393.465331.8755200.3495115.495007.1934945.824860.9014576.7424498.7134450.7874389.8644318.784249.9944197.7424111.3674056.7994001.1773966.7063900.0983841.4283792.1043775.936NANANA
 us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:StatementBusinessSegments us-gaap:CorporateAndOtherNANA2.2NANANA5.4NANANA12.4NANANA11.6NANANA11.2NANANA10.6NANANA10.8NANANANANANANANANANANANANANANANANANANA
us-gaap:Goodwill ▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▁█████████▄▃▃▃▃52.42652.42652.42652.42652.42652.42652.42652.42652.42652.42657.67257.67257.67257.67257.67257.67257.67257.67257.67257.67257.67257.67257.67257.67257.67257.97657.97655.8775.24676.25776.25776.76276.76276.76275.95973.78373.78373.78339.04526.11226.11225.96525.935NANANA
us-gaap:OperatingLeaseRightOfUseAsset █████▇████▁70.94171.4171.89171.97272.58865.30369.74670.1470.44270.8340.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent ▁▇▆█▅▅▄▃▂▃▃19.74927.55226.94729.23525.84225.61423.39421.94320.54922.75123.065NANA160.755153.131149.241148.706145.744141.443135.954148.822142.791143.646140.585143.523146.688151.174152.206100.02225.468240.437254.007256.341249.364248.67249.972252.394263.311212.209186.653191.04421.556195.793NANANA
us-gaap:EquitySecuritiesFvNi █▂▁69.92161.13259.318NANANA51.258NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AccountsPayableCurrent ▃▃▃▂▄▂▄▃▂▄▃▂▂▁▃▂▂▂▄▂▁▁▄▁▂▁▄▂▂▆▇▆▆▆█▅▅▅▆▆▄▆▇104.04893.1106.61383.697110.67588.184110.21991.35880.619109.922108.37280.89276.55867.168107.28972.77769.16572.354115.54581.89863.05659.14114.34963.17270.08662.853112.97482.36673.349163.655182.088158.36153.425161.503198.914140.536148.734134.261166.954154.249128.853150.648171.707NANANA
us-gaap:AccruedLiabilitiesCurrent █▁▆▃▁▁▆▃▂▅▄▁▃38.27128.15135.15930.127.80627.7735.43130.68629.5933.39932.74527.80531.101NA33.791NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LiabilitiesCurrent █▄▄▃▅▄▄▂▄▄▅▂▁▅▆▆▆▂▃▂▄▃▃▃▁▂▂▁▃▄▅▄▅▄▄▄▅▅▅▄▃▃▄891.909492.799505.879474.839656.562565.806530.713399.185516.735566.642639.584346.903289.07669.697697.502673.251682.114366.825407.528341.882501.714431.841474.68447.737306.946325.628385.269270.819464.331570.221625.34550.236582.461579.783576.149547.853584.649605.029627.174576.552454.949454.115579.175NANANA
us-gaap:LongTermDebtCurrent 250.0NANA52.052.0NA52.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA7.4097.4747.377.3630.360.358NANANA
us-gaap:OperatingLeaseLiabilityCurrent NANA4.249NANANA4.128NANA4.120.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesCurrent ▇▇▆▅▅▇▅▅▅▇▄▅▄▂▁▁▁▁▂▇██▆▆▅▇▆▅▅█▆▆▆█▆▆▅▆▆▅▄▄▄171.685161.632149.831140.24123.258174.286130.979130.089124.169175.454120.358133.404121.41483.18464.91161.43664.41765.23870.604164.119177.45178.809147.896146.368131.017160.13141.395128.726123.63180.834145.495145.602151.122184.534142.544147.723130.387149.547141.789139.252109.331119.837110.547NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 us-gaap:LongTermDebt us-gaap:LongtermDebtType ava:FutureLongTermDebtMaturitiesIncludingLongTermDebtToAffiliatedTrustsNANA2075.047NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA1235.647NANANANANANANA
us-gaap:LongTermDebtNoncurrent ▁███▃1758.9612008.7422008.5342009.31844.161NA1843.768NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA1170.1751169.8261084.6611094.9781101.8141101.499NANANA
us-gaap:DeferredIncomeTaxLiabilitiesNet █▇▆▃▂▁▁620.02607.707594.712550.571540.494525.217528.513NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▄▅▅▅▅▅▅▅▅▆▆▅▅▅▅▅▆▆▆▅▅▅▅▄▄▄▄▁▁▂▂▇▇██▅▆▆▇▄▄▃▃188.912199.67211.88199.912204.506207.313212.006210.292214.983218.456222.537191.021195.227200.162203.566216.464219.584223.304226.552202.329202.063202.013201.453188.711188.862188.798189.48995.037103.421113.416122.513252.331263.27274.18283.985214.838225.25235.576246.177162.548169.557157.698161.189NANANA
us-gaap:OtherLiabilitiesNoncurrent ▅▆▇██▇▆▇▆▆▁▁▁▄▄▄▅▅▄▄▅▅▅▅▄▄▄▃▃▃▃▃▃▂▃▂▂▃▃▂▂▂▃182.543186.657214.999240.47251.49237.664201.189229.339211.401195.74871.03169.42569.433147.705143.577158.699162.158168.587153.319135.578165.419174.08161.5165.838146.473149.165146.24120.553114.537119.295130.318122.214122.488106.395110.215105.481104.379110.001116.08491.99592.89896.125109.703NANANA
us-gaap:OperatingLeaseLiabilityNoncurrent █████▇▇███▁68.8268.27667.71670.75870.3362.14565.56568.92568.22867.6350.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA4.799NANANA4.375NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA4.827NANANA4.383NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA4.852NANANA4.399NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive NANA4.865NANANA4.411NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA96.734NANANA91.654NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:StockholdersEquity ███▇▇▇▇▇▇▇▆▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁2069.9662068.592029.7261982.8511975.0381959.0951939.2841893.5681884.0341867.311773.221749.5521762.4581758.3891729.8281670.9461686.8941685.4461648.4761628.5241616.7371589.2681528.2871508.1971514.0051506.7591483.2421491.7571409.5451351.1131318.2671310.4571314.4211304.7381277.1351277.1821216.4141207.6711185.8751170.3881167.5881160.3791125.7841105.8711085.21NA
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest ███▇▇▇▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▄▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁2069.9662068.592029.7261982.8511975.0381959.0951939.2841893.5681884.0341868.2221774.0451750.3511762.7071758.5711730.4841670.3271687.1731685.6761648.7271628.7871617.0271589.5911528.6261508.5531514.3931507.1751483.6711492.2081410.0161330.4821298.2661289.4041293.8141283.9761259.4771259.7441216.8421208.1391185.7011170.9181168.1351159.8071125.184NANA1062.782
us-gaap:CommonStockValue ███▇▇▇▇▆▆▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▄▄▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁1303.4111285.9991286.0681265.1911234.9011209.3121210.7411186.9251157.0241140.2421136.4911135.5431134.3041131.5491133.4481077.2151075.6671073.0981075.2811073.4811052.191032.0231004.3361002.7161001.253998.975999.961007.764885.741899.037896.993898.199895.255891.759889.237887.53861.053857.747855.188848.709842.054833.617827.592NANANA
us-gaap:RetainedEarningsAccumulatedDeficit ██▇▇▇▇▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▅▄▄▄▄▄▄▄▃▂▂▂▂▂▂▂▂▁▁▁▁▁780.31796.654758.036727.274749.971759.837738.802714.026734.555734.774644.595623.229637.578636.468604.47600.132618.708619.963581.014562.905572.576565.447530.94512.988520.537515.842491.599488.342528.285436.37407.092399.053406.195398.804376.94377.111360.947355.818336.15326.548330.543331.284302.518NANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▁▁▁▄▄▄▄▆▆▅▅▄▄▄▅▆▆▆▆▆▅▅▆▆▆▅▅██▇▇▅▆▆▆▇▇▇▇████-13.755-14.063-14.378-9.614-9.834-10.054-10.259-7.383-7.545-7.706-7.866-9.22-9.424-9.628-8.09-7.02-7.202-7.385-7.568-7.599-7.739-7.879-6.65-7.151-7.397-7.642-7.888-3.898-4.01-4.925-5.819-7.848-7.636-6.587-6.7-4.897-5.158-5.426-5.637-4.339-4.462-4.522-4.326NANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:CommonStock▅▅▅▅▅▅▅▅▅▅▄▅▅▅▆▅▅▅▄▅▅▅▄▅▅▅▁█▅▅▄▅▅▅▄▅▅▅▄▅▅▅▅▅▅▅15.6240.06517.20529.46623.7150.17520.67227.9714.7390.19-1.224-0.0030.9950.23253.2310.2430.9320.315-1.48919.58320.02327.15-1.3970.3170.6670.413-153.501151.5211.3420.638-4.4791.4621.8681.149-5.31625.1242.1381.437-2.0035.3387.428.4587.9325.1679.1350.375
 us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents us-gaap:CommonStock▃▁▃▁▃▁▄▃▃█▁▂▃▃▂▄▃▁▃▃▃▃▂▂▃▂▃▂▆▃▂▂▂▂▄▂▂▂▁▁▁▁▁▁▁▁1.7880.8592.0330.8241.8740.8042.1421.9312.0434.4520.9651.2421.761.7981.4752.4961.6370.9221.6031.7541.7411.9671.4561.4981.5681.5131.6151.2963.1461.6191.5121.5221.5071.4612.3621.1131.1211.120.9170.9140.9150.8890.7890.790.7890.729
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▆▃▄▃▆▃▄▃█▁▄▄█▅▄▄▆▅▅▃▅▃▄▄▆▁▃▃▇▃▃▃▅▃▃▄▅▂▄▃▅▂▄▂▄44.973145.0948.47682.6464.614135.27457.72187.8255.79196.881-3.9190.3790.65184.775102.78578.98778.811149.715104.14998.16750.404105.54764.39679.13285.334146.7781.55441.72667.09156.89840.15546.60750.416105.37959.14557.69178.418121.29929.04176.97260.19103.26226.72886.89933.75681.054
us-gaap:NetCashProvidedByUsedInInvestingActivities ▂▂▂▂▂▂▂▂▃▂▂▂▂▃▂▂▂▃▂▂▂▃▂▂▂▃▂▃█▃▃▃▃▃▃▄▄▁▂▂▃▅▂▃▄▄-114.378-96.461-109.738-109.241-96.633-95.131-125.196-130.282-92.369-97.664-132.745-114.782-105.551-87.354-131.752-112.762-99.662-89.927-117.513-108.329-114.97-91.654-116.725-95.513-95.414-80.175-96.977-73.997127.935-60.697-78.659-78.654-68.218-86.686-65.603-46.556-28.193-154.316-114.57-103.732-64.1380.159-100.812-67.194-37.883-47.334
us-gaap:NetCashProvidedByUsedInFinancingActivities ▇▄▅▅█▄▆▆▆▃█▅▅▃▆▆▅▄▅▅▆▅▆▅▅▃▇▁▃▃▆▆▅▅▅▄▄▆▇▆▅▂▇▅▅▄86.785-41.178-9.289-5.046129.494-31.1262.91739.68537.923-97.986130.14110.24923.961-87.3230.42335.0818.082-42.11614.7873.72465.321-11.6153.4999.4534.241-66.665107.175-165.305-77.23-88.60329.09938.61514.016-4.96-1.03-21.599-29.51231.05882.08834.94712.027-110.99786.815-1.5533.054-31.152
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect ▅▄▁▃█▄▄▄17.387.451-70.551-31.64797.4759.023-4.558-2.777NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AmortizationOfFinancingCosts ▂▃▃▄▂▁▁▁▁▁▁▁▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▃▄▄▄▄▄▄▄▄▄▄█▄▄▆▆▄▅▅0.7480.8230.9080.9640.7120.6530.6720.670.6690.6690.640.6920.820.8150.8140.8130.8140.8130.8820.8530.8660.8760.8750.8770.8790.8950.8930.910.9360.9530.9720.9460.9480.9470.9270.950.9610.9651.4310.9690.9811.2361.21.0331.131.051
us-gaap:DeferredIncomeTaxExpenseBenefit ▂▂▅▂▁▁▂▂▁▂▁▂▂▁▂▃▃▃▄▄▃▄▄▂▂▁▄█▃▂▂▃▁▂▂▂▂▁▁▃▂▂▄▂▂▂5.1195.96647.1646.2-1.635-6.7654.8794.642-3.3068.883-2.00511.8473.777-5.04911.41522.07318.55517.61437.29730.59422.62234.0339.426.226.243-0.08232.93487.17422.7081.4537.0217.916-2.5241.123.06911.8586.825-0.303-6.77625.6254.1920.96627.2442.154.1854.155
us-gaap:DepreciationDepletionAndAmortization ▆▆▆▆█▆▆▅▆▅▅▅▅▅▄▄▄▄▄▄▄▄▃▃▃▃▃▃▂▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁56.13955.34854.37254.09964.33151.42151.05150.18655.63449.12347.5847.15446.76145.82344.85244.01343.70643.08442.51141.34340.7840.29138.31337.39136.75235.37935.43834.35633.96134.58234.39633.90333.27231.61833.10931.64631.32530.32229.32728.30528.24927.71928.43426.6526.39626.146
us-gaap:IncreaseDecreaseInAccountsPayable ▅▄▅▅▃▃▆▅▁▆▆▅▄▂▆▄▃▂▆▆▄▁▆▄▅▂▅▅▂▃▆▅▄▂█▄▅▃▄▇▂▃▆▆▂▃10.701-2.5913.1766.532-10.333-19.52715.83711.027-36.0916.69715.9225.250.355-21.99721.83-0.557-9.196-20.23922.38214.278-0.68-30.80424.24-5.9824.149-30.5459.88811.575-22.96-11.06515.3673.35-6.328-20.77840.972-7.32712.656-16.112-6.03827.04-22.36-16.67423.6721.912-22.802-9.174
us-gaap:IncreaseDecreaseInInventories █▄▄▅▆▃▄▅▆▅▅▅▆▃▃▅▇▄▄▆▆▃█▆▆▁▄▇▇▃▃▆▇▂▄▅▇▂▃▇▆▃▃▅█▄19.619-4.291-1.5761.69310.652-9.901-1.150.0736.8310.3941.1165.8657.641-8.815-7.8864.77414.008-6.129-3.0986.4427.753-10.26318.8298.8637.087-22.571-3.58518.48816.632-12.141-11.89711.52115.004-17.137-3.61-0.07214.783-15.652-12.87217.1959.287-10.222-7.8982.96721.781-5.602
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▆▃▄▃▆▃▄▃█▁▄▄█▅▄▄▆▅▅▃▅▃▄▄▆▁▃▃▇▃▃▃▅▃▃▄▅▂▄▃▅▂▄▂▄44.973145.0948.47682.6464.614135.27457.72187.8255.79196.881-3.9190.3790.65184.775102.78578.98778.811149.715104.14998.16750.404105.54764.39679.13285.334146.7781.55441.72667.09156.89840.15546.60750.416105.37959.14557.69178.418121.29929.04176.97260.19103.26226.72886.89933.75681.054
us-gaap:NetIncomeLoss ▂▅▄▁▂▄▄▁▂█▄▁▂▄▂▁▂▅▃▁▂▄▃▂▂▄▃▁▇▄▃▁▂▃▂▁▂▃▂▁▂▃▂▁▂▃14.07468.01758.7354.87617.45348.42450.7765.0925.319115.79445.84310.11925.57754.8927.5784.45121.77162.11640.09112.23427.25456.05238.52113.01125.24646.44932.2210.451100.87148.49931.66611.41325.65742.34115.8585.78618.17838.38824.60310.70223.00141.91825.72912.34625.5428.81
us-gaap:ProfitLoss NANA58.7354.87617.45348.42450.7765.0925.016115.88145.86910.12925.64454.95627.6154.45821.72262.13740.10312.26127.28756.06838.53813.04325.27446.46232.24310.471100.58248.98131.53211.93125.7343.10116.0935.96218.53238.21325.97111.63723.52842.40326.2513.33426.04729.317
us-gaap:ShareBasedCompensation ▃▂▄▂▄▂▄▄▄█▁▃▄▄▃▅▃▂▃▄▄▄▃▃▃▃▄▃▆▃▃▃▃▃▃▃▃▃1.6540.6262.1410.8791.9540.8722.4021.9422.1644.8450.1521.3371.9151.9631.553.1661.8110.8321.632.0251.9232.3131.6511.8221.7341.7071.8531.4233.2871.5511.51.6381.6161.4641.2531.3811.541.618NANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▂▂▂▂▂▂▂▂▃▂▂▂▂▃▂▂▂▃▂▂▂▃▂▂▂▃▂▃█▃▃▃▃▃▃▄▄▁▂▂▃▅▂▃▄▄-114.378-96.461-109.738-109.241-96.633-95.131-125.196-130.282-92.369-97.664-132.745-114.782-105.551-87.354-131.752-112.762-99.662-89.927-117.513-108.329-114.97-91.654-116.725-95.513-95.414-80.175-96.977-73.997127.935-60.697-78.659-78.654-68.218-86.686-65.603-46.556-28.193-154.316-114.57-103.732-64.1380.159-100.812-67.194-37.883-47.334
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▇▆▆▆▅▅▇▇▆▅█▇▆▄█▇▅▅▇▆▅▅▇▅▆▄▅▅▄▃▄▄▄▄▅▃▃▃▄▄▂▂▃▃▁▁116.62497.203106.472108.35493.95595.525121.546120.976106.37393.615128.134113.084101.31581.817124.486110.13990.95186.763118.572105.25793.93788.878120.62495.04996.15581.59795.75293.2576.78959.72573.65175.36874.69970.64592.74757.96462.70557.77170.18470.71649.22849.65464.14457.79837.73342.552
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▇▄▅▅█▄▆▆▆▃█▅▅▃▆▆▅▄▅▅▆▅▆▅▅▃▇▁▃▃▆▆▅▅▅▄▄▆▇▆▅▂▇▅▅▄86.785-41.178-9.289-5.046129.494-31.1262.91739.68537.923-97.986130.14110.24923.961-87.3230.42335.0818.082-42.11614.7873.72465.321-11.6153.4999.4534.241-66.665107.175-165.305-77.23-88.60329.09938.61514.016-4.96-1.03-21.599-29.51231.05882.08834.94712.027-110.99786.815-1.5533.054-31.152
us-gaap:ProceedsFromIssuanceOfLongTermDebt NANA0.0NANANA180.00.0NANA0.00.0NANA90.00.0NANA175.0NANANA100.0NANANA75.0NANANA0.0NANANA80.0NANANANANANANANANANANA
us-gaap:RepaymentsOfLongTermDebt ▁█0.7320.759NA0.6980.7310.7NA0.6650.6650.665NA0.634273.1333.0370.8220.8220.8210.82270.79290.7920.7910.7920.7310.760.7750.6390.60439.2180.080.06950.0470.0560.2580.1010.1290.09911.1990.0650.0930.0150.0940.095100.00610.0910.0860.059
us-gaap:PaymentsOfDividends ██▇▇▇▇▆▆▆▆▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▄▃▃▃▃▃▃▃▃▂▂▂▂▂▂▁▁▁▁29.29429.39927.97327.57327.31927.38926.025.61925.53825.61524.47724.46824.46724.63423.2423.02723.02623.16721.98221.90521.72221.54520.56920.5620.55120.71719.76220.22519.1119.21718.31318.29618.28318.38417.33717.11417.02817.07316.05215.95615.94915.7814.29713.8513.78213.753
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value13031285128612651234120912101186115711401136113511341131113310771075107310751073105210321004100210019989991007885899896898895891889887861857855848842833827778
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets19.620.120.120.119.619.619.919.919.719.419.720.420.620.620.619.820.020.120.320.620.820.820.521.221.421.321.223.221.120.820.620.420.620.620.621.220.420.220.321.421.921.821.021.6

Common Stock Shares Authorized

us-gaap:CommonStockSharesAuthorized us-gaap:SubsidiarySaleOfStock

us-gaap:CommonStockSharesAuthorized

ava:SalesAgencyAgreement


Common
Period End2021-03-312020-12-312020-09-302020-06-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312012-08-312010-08-312009-12-31
Value3.23.23.23.24.64.64.63.83.83.83.83.83.83.83.83.83.83.83.82.726393.08751.25
Percentage of CommonStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Preferred Stock Shares Authorized

us-gaap:PreferredStockSharesAuthorized

us-gaap:PreferredStockSharesAuthorized


Preferred
Period End2020-12-31
Value10000000.0
Percentage of PreferredStockSharesAuthorized100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value696968676767666565656665656564646464646362626262626264606060605959595958585858585757555555
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value696968676766666565656565656464646464636362626262626263606060595959595958585858575756555554
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.20.980.860.070.260.720.760.080.381.760.70.150.390.840.430.070.340.970.630.190.430.90.620.210.410.750.520.161.680.810.530.190.430.710.260.10.310.660.420.180.40.730.450.220.460.53
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.20.980.860.070.260.720.760.080.381.760.70.150.390.830.420.070.340.960.620.190.430.890.610.210.40.740.510.161.670.810.530.190.430.710.260.10.310.650.420.180.390.730.450.220.460.52
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value535.0961748475.2522511547102555264.6332162401227543913254628101014933112442146.04718382310234123122528
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues14.21.96.312.513.11.98.529.212.73.58.113.56.71.67.014.310.04.18.613.110.14.27.610.56.93.532.610.17.53.37.08.83.41.85.48.55.33.16.48.86.33.47.16.3

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1468535.0961748475.2522511647102555264.642162401227543913254628101014933112443146.22318382411234224132629
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.816.614.21.96.312.513.11.98.429.312.73.58.113.56.71.67.014.310.04.18.613.110.14.27.610.56.93.532.510.27.53.57.08.93.51.85.58.55.63.46.58.96.53.67.26.4

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value266310293244243308291253261329295259266315315266258321319263257312316277279356345268249397381300294397369310295373378308305391311329298388
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues89.475.377.189.587.578.979.989.386.883.179.387.783.377.079.489.682.273.679.586.980.774.681.888.683.079.983.889.179.981.085.289.583.682.490.091.285.982.686.289.984.682.283.289.782.985.1

Income Loss From Continuing Operations

us-gaap:IncomeLossFromContinuingOperations

us-gaap:IncomeLossFromContinuingOperations


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1468584.8761748505.092511545102554274.4512162401227563312254630103147308.452441
Percentage of IncomeLossFromContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.716.515.41.86.312.413.91.88.429.212.33.48.013.46.91.56.914.210.04.08.513.48.74.17.410.47.43.510.09.76.82.56.98.5

us-gaap:IncomeLossFromContinuingOperations us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5.0580.483-0.049-0.938-1.48-0.953.252-1.0733.024
Percentage of IncomeLossFromContinuingOperations35.90.7-0.1-19.2-8.5-2.06.4-21.111.9
Percentage of Revenues1.70.1-0.0-0.3-0.5-0.20.9-0.41.0
Percentage of Revenues us-gaap:CorporateNonSegment ava:NonUtilityRevenue3417.6255.60.0-351.3-580.4-115.40.0-102.3133.7

us-gaap:OperatingSegments, ava:UtilityRevenue


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value9.01667585.8141849476.16322
Percentage of IncomeLossFromContinuingOperations64.199.3100.1119.2108.5102.093.6121.188.1
Percentage of Revenues3.016.415.52.16.812.713.02.27.4
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue3.016.40.02.16.812.70.02.27.5

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

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.2993.4763.1040.2681.3283.3952.6330.1971.076
Percentage of IncomeLossFromContinuingOperations9.25.15.35.57.67.05.23.94.2
Percentage of Revenues0.40.80.80.10.50.90.70.10.4
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AlaskaElectricLightPower12.327.10.03.013.327.80.02.512.3

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value7.71764555.5461745445.96621
Percentage of IncomeLossFromContinuingOperations54.894.294.8113.7100.995.088.4117.283.8
Percentage of Revenues2.615.514.62.06.311.812.32.17.1
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AvistaUtilities2.716.00.02.16.612.20.02.27.3

Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1680645.7359.53456544.9592314554113065589.611349563194388531840725117477748174168247.5728594115376638184147
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues5.519.416.92.13.414.614.81.77.736.814.63.99.716.014.83.211.121.915.86.513.821.013.96.011.916.312.55.915.315.710.95.211.714.25.92.28.413.19.54.510.313.910.35.011.610.3

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2.398125.5790.859-7.9198.5323.229-0.131-1.741308.5931.5485.20910315.1531333237.6061631206.1151526207.3011628175.45915258.1551.6081021153.7171323125.031517
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.82.91.50.3-2.82.20.9-0.0-0.67.62.30.51.62.67.81.74.17.65.82.55.27.65.21.94.55.95.12.45.35.73.81.64.45.22.00.53.04.73.61.13.85.03.31.44.43.9

us-gaap:IncomeTaxExpenseBenefit us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.3450.113-0.053-0.26-0.395-0.173-0.403-0.3380.826
Percentage of IncomeTaxExpenseBenefit56.10.9-0.9-30.35.0-2.0-12.5258.0-47.4
Percentage of Revenues0.50.0-0.0-0.1-0.1-0.0-0.1-0.10.3
Percentage of Revenues us-gaap:CorporateNonSegment ava:NonUtilityRevenue908.859.80.0-97.4-154.9-21.00.0-32.236.5

us-gaap:OperatingSegments, ava:UtilityRevenue


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.053125.6321.119-7.5248.7053.6320.207-2.567
Percentage of IncomeTaxExpenseBenefit43.999.1100.9130.395.0102.0112.5-158.0147.4
Percentage of Revenues0.42.91.50.4-2.72.21.00.1-0.9
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue0.42.90.00.4-2.72.20.00.1-0.9

us-gaap:IncomeTaxExpenseBenefit us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.4681.3331.1710.0590.481.3010.9910.0820.38
Percentage of IncomeTaxExpenseBenefit19.511.021.06.9-6.115.230.7-62.6-21.8
Percentage of Revenues0.20.30.30.00.20.30.30.00.1
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AlaskaElectricLightPower4.410.40.00.74.810.70.01.14.3

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.585104.4611.06-8.0047.4042.6410.125-2.947
Percentage of IncomeTaxExpenseBenefit24.488.180.0123.4101.186.881.8-95.4169.3
Percentage of Revenues0.22.61.20.4-2.91.90.70.0-1.0
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AvistaUtilities0.22.70.00.4-3.02.00.00.0-1.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1468584.8761748505.092511545102554274.4512162401227563813254632101004831112542155.78618382410234125122528
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.716.515.41.86.312.413.91.88.429.212.33.48.013.46.91.56.914.210.04.08.513.49.94.17.510.47.83.532.39.97.13.47.38.83.91.75.38.55.63.16.48.86.93.47.16.3

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1468584.8761748505.092511545102554274.4512162401228563813254632101004831112542155.78618382410234125122528
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0105.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.716.515.41.86.312.413.91.88.429.212.33.48.013.46.91.56.914.210.04.09.013.49.94.17.510.47.83.532.39.97.13.47.38.83.91.75.38.55.63.16.48.86.93.47.16.3
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value31101872834827330396777365394813156115823961106703557896632629366355785412948786034558462376167
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues10.624.722.910.512.521.120.110.713.216.920.712.316.723.020.610.417.826.420.513.119.325.418.211.417.020.116.210.920.119.014.810.516.417.610.08.814.117.413.810.115.417.816.810.317.114.9

us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.084-1.122-1.507-1.576-0.593-0.587-2.601-0.535-4.226
Percentage of OperatingIncomeLoss3.4-1.1-1.7-5.5-1.7-0.7-3.5-1.8-10.6
Percentage of Revenues0.4-0.3-0.4-0.6-0.2-0.2-0.7-0.2-1.4
Percentage of Revenues us-gaap:CorporateNonSegment ava:NonUtilityRevenue732.4-593.70.0-590.3-232.5-71.30.0-51.0-186.9

us-gaap:OperatingSegments, ava:UtilityRevenue


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value3210388303582753043
Percentage of OperatingIncomeLoss103.4101.1101.7105.5101.7100.7103.5101.8110.6
Percentage of Revenues11.025.023.311.012.721.220.810.814.6
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue11.025.00.011.012.821.30.010.914.7

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

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value3.2756.3245.7511.793.3026.2465.1141.783.016
Percentage of OperatingIncomeLoss10.36.26.66.39.57.67.05.97.6
Percentage of Revenues1.11.51.50.71.21.61.40.61.0
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AlaskaElectricLightPower31.149.30.020.333.051.20.022.834.5

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value299682283276702840
Percentage of OperatingIncomeLoss93.194.995.199.292.293.196.695.9103.0
Percentage of Revenues9.923.421.810.411.619.619.410.213.6
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AvistaUtilities10.324.20.010.712.020.30.010.514.1

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value308000.0315000.0-4764000.0220000.0220000.0205000.0-2876000.0162000.0161000.0160000.01354000.0204000.0204000.0204000.0-1070000.0182000.0183000.0183000.031000.0140000.0140000.0-1229000.0501000.0246000.0245000.0246000.0-3990000.0112000.0915000.0894000.02029000.0-212000.0-1049000.0113000.0-1803000.0261000.0268000.0211000.0-1298000.0123000.060000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.10.1-1.30.10.10.1-0.80.10.10.00.40.10.10.0-0.30.10.10.00.00.00.0-0.30.10.10.10.1-1.00.00.30.20.5-0.1-0.30.0-0.40.10.10.0-0.30.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-30
Value308000.0315000.0-4764000.0220000.0220000.0205000.0-2876000.0162000.0161000.0160000.01354000.0204000.0204000.0204000.0-1070000.0182000.0183000.0183000.031000.0140000.0140000.0-1229000.0501000.0246000.0245000.0246000.0-3990000.0112000.0915000.0894000.02029000.0-212000.0-1049000.0113000.0-1803000.0261000.0268000.0211000.0-1298000.0123000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.10.1-1.30.10.10.1-0.80.10.10.00.40.10.10.0-0.30.10.10.00.00.00.0-0.30.10.10.10.1-1.00.00.30.20.5-0.1-0.30.0-0.40.10.10.0-0.30.0
Percentage of Revenues us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value103.6846.836-2.1680.5310.3825.933-0.188.2680.9072.493-1.3791.907-4.4790.4651.8411.6563.1013.0531.5623.0412.4223.112.1231.8362.2313.0832.6083.0552.5511.1120.9842.4362.14510-3.809-0.678-0.619-1.124-1.626-0.803-0.632-4.482-0.807-0.969-1.699
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues3.40.91.8-0.80.20.11.6-0.12.70.20.7-0.50.6-1.10.10.60.50.70.80.51.00.60.80.70.50.50.70.91.00.50.20.30.70.42.5-1.1-0.2-0.1-0.3-0.5-0.2-0.1-1.2-0.2-0.3-0.4

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value584.8761748505.092511545102554274.4582162401227563813254632101004831112543165.96218382511234226132629
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues15.41.86.312.413.91.88.329.212.33.48.013.46.91.56.914.210.04.08.613.410.04.27.510.47.83.532.210.07.03.67.38.93.91.85.48.45.93.46.58.97.03.67.26.4

Regulated Operating Revenue

us-gaap:RegulatedOperatingRevenue

us-gaap:RegulatedOperatingRevenue


Regulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value298412380272278389363282298388365289312402
Percentage of RegulatedOperatingRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.099.999.999.999.899.699.699.298.098.197.797.998.3

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

ava:CommercialElectric


Revenue
Period End2021-06-302020-06-30
Value8774
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0
Percentage of Revenues29.226.7
Percentage of Revenues ava:CommercialElectric0.00.0

ava:CommercialandGovernmentalElectric


Revenue
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value81838474858586818483878386
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.0100.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues19.621.931.126.721.823.530.427.021.222.429.526.021.2
Percentage of Revenues ava:CommercialandGovernmentalElectric0.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:Electric


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value216238231214192234233207194
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax248.90.00.00.0257.70.00.00.00.0
Percentage of Revenues72.657.860.878.668.960.164.173.264.7
Percentage of Revenues ava:Electric0.00.00.00.00.00.00.00.00.0

ava:IndustrialElectric


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
Value2726252824242528262525302725
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax31.50.00.00.033.30.00.00.00.00.00.00.00.00.0
Percentage of Revenues9.26.46.610.48.96.37.110.08.76.47.010.48.86.1
Percentage of Revenues ava:IndustrialElectric0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:OtherElectric


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
Value6.5326.145.9964.5513.4155.2898.5365.864.3798.1948.598.5643.9196.291
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.50.00.00.04.60.00.00.00.00.00.00.00.00.0
Percentage of Revenues2.21.51.61.71.21.42.32.11.52.12.32.91.21.5
Percentage of Revenues ava:OtherElectric0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:PublicStreetandHighwayLightingElectric


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
Value1.9281.9121.8961.911.9051.8441.8661.9151.9561.9661.9871.9261.9621.927
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.20.00.00.02.60.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.60.50.50.70.70.50.50.70.70.50.50.70.60.5
Percentage of Revenues ava:PublicStreetandHighwayLightingElectric0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:ResidentialElectric


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
Value88119110888211310781761211018578121
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax102.20.00.00.0111.30.00.00.00.00.00.00.00.00.0
Percentage of Revenues29.828.929.232.529.829.229.428.725.530.627.328.924.729.6
Percentage of Revenues ava:ResidentialElectric0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:RetailElectric


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value205228221203184225220197186
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax235.90.00.00.0247.20.00.00.00.0
Percentage of Revenues68.855.458.274.866.157.860.469.761.8
Percentage of Revenues ava:RetailElectric0.00.00.00.00.00.00.00.00.0

ava:TransmissionElectric


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value4.8013.4954.1155.9384.4093.7744.724.0584.255.1525.0314.832
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.50.00.00.05.90.00.00.00.00.00.00.0
Percentage of Revenues1.60.81.12.21.61.01.31.41.41.31.41.6
Percentage of Revenues ava:TransmissionElectric0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers, us-gaap:StatementBusinessSegments

ava:CommercialAndGovernmentalNaturalGas, ava:AvistaUtilities


Revenue
Period End2021-03-312020-09-302020-03-312019-09-30
Value399.343910
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.0
Percentage of Revenues9.63.410.13.6
Percentage of Revenues ava:CommercialAndGovernmentalNaturalGas ava:AvistaUtilities0.00.00.00.0

ava:CommercialElectric, ava:AlaskaElectricLightPower


Revenue
Period End2021-06-302020-06-30
Value6.1775.729
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.17.7
Percentage of Revenues2.12.1
Percentage of Revenues ava:CommercialElectric ava:AlaskaElectricLightPower0.00.0

ava:CommercialElectric, ava:AvistaUtilities


Revenue
Period End2021-06-302020-06-30
Value8068
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax92.992.3
Percentage of Revenues27.124.7
Percentage of Revenues ava:CommercialElectric ava:AvistaUtilities0.00.0

ava:CommercialNaturalGas, ava:AvistaUtilities


Revenue
Period End2021-06-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value15143932101336279.4371437
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax17.919.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues5.25.110.18.83.64.49.27.53.24.69.1
Percentage of Revenues ava:CommercialNaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.0

ava:CommercialandGovernmentalElectric, ava:AlaskaElectricLightPower


Revenue
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.7726.2755.5825.7296.1994.8764.8574.8374.8214.8586.5466.5418.044
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.07.70.00.00.00.00.00.00.00.00.0
Percentage of Revenues1.21.62.02.11.61.31.71.61.21.32.22.02.0
Percentage of Revenues ava:CommercialandGovernmentalElectric ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:CommercialandGovernmentalElectric, ava:AvistaUtilities


Revenue
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value76777968788081767978807678
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.092.30.00.00.00.00.00.00.00.00.0
Percentage of Revenues18.520.329.124.720.222.128.725.420.021.127.323.919.3
Percentage of Revenues ava:CommercialandGovernmentalElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:Electric, ava:AlaskaElectricLightPower


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1012118.7979.978129.7367.6878.62
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.00.00.00.013.40.00.00.00.0
Percentage of Revenues3.53.13.13.23.63.12.72.72.9
Percentage of Revenues ava:Electric ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.00.0

ava:Electric, ava:AvistaUtilities


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value206225219205182222223200186
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax236.90.00.00.0244.30.00.00.00.0
Percentage of Revenues69.154.757.775.465.357.061.470.561.8
Percentage of Revenues ava:Electric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.0

ava:IndustrialElectric, ava:AlaskaElectricLightPower


Revenue
Period End2021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.8990.00.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.50.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues ava:IndustrialElectric ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.00.00.00.0

ava:IndustrialElectric, ava:AvistaUtilities


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
Value2724252824242528262525302725
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax31.50.00.00.033.30.00.00.00.00.00.00.00.00.0
Percentage of Revenues9.26.06.610.48.96.37.110.08.76.47.010.48.86.1
Percentage of Revenues ava:IndustrialElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:IndustrialandInterruptibleNaturalGas, ava:AvistaUtilities


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
Value1.8192.2241.8521.5381.5432.1941.5331.01.1031.6270.9861.0061.0781.683
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.00.00.02.10.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.60.50.50.60.60.60.40.40.40.40.30.30.30.4
Percentage of Revenues ava:IndustrialandInterruptibleNaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:NaturalGas, ava:AvistaUtilities


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5413211034531291073445
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax62.60.00.00.071.60.00.00.00.0
Percentage of Revenues18.332.229.212.719.233.129.612.115.1
Percentage of Revenues ava:NaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.0

ava:OtherElectric, ava:AvistaUtilities


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
Value6.5326.145.9964.5513.4155.2898.5365.864.3798.1948.598.5643.9196.291
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.50.00.00.04.60.00.00.00.00.00.00.00.00.0
Percentage of Revenues2.21.51.61.71.21.42.32.11.52.12.32.91.21.5
Percentage of Revenues ava:OtherElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:OtherNaturalGas, ava:AvistaUtilities


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
Value1.4061.1251.1261.1251.1251.1251.1251.1251.1251.1251.1251.1251.1251.125
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.60.00.00.01.50.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.50.30.30.40.40.30.30.40.40.30.30.40.40.3
Percentage of Revenues ava:OtherNaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:PublicStreetandHighwayLightingElectric, ava:AlaskaElectricLightPower


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
Value0.0590.060.0670.0650.0590.0610.0660.0660.0590.0630.0660.0660.0630.068
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.00.00.00.10.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues ava:PublicStreetandHighwayLightingElectric ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:PublicStreetandHighwayLightingElectric, ava:AvistaUtilities


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
Value1.8691.8521.8291.8451.8461.7831.81.8491.8971.9031.9211.861.8991.859
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.10.00.00.02.50.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.60.40.50.70.70.50.50.70.60.50.50.60.60.5
Percentage of Revenues ava:PublicStreetandHighwayLightingElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:ResidentialElectric, ava:AlaskaElectricLightPower


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
Value4.2516.0485.3823.154.195.8664.7942.7643.7245.8524.8262.9874.1556.538
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.90.00.00.05.60.00.00.00.00.00.00.00.00.0
Percentage of Revenues1.41.51.41.21.51.51.31.01.21.51.31.01.31.6
Percentage of Revenues ava:ResidentialElectric ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:ResidentialElectric, ava:AvistaUtilities


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
Value8411310585781071027872115968274114
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax97.30.00.00.0105.70.00.00.00.00.00.00.00.00.0
Percentage of Revenues28.427.427.731.428.327.728.127.724.229.126.027.923.428.0
Percentage of Revenues ava:ResidentialElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:ResidentialNaturalGas, ava:AvistaUtilities


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
Value3387732034847020277763193080
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax38.70.00.00.046.70.00.00.00.00.00.00.00.00.0
Percentage of Revenues11.321.219.47.612.521.619.47.19.319.517.16.59.619.7
Percentage of Revenues ava:ResidentialNaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ava:RetailElectric, ava:AlaskaElectricLightPower


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1012118.7979.978129.7367.6878.62
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.00.00.00.013.40.00.00.00.0
Percentage of Revenues3.53.13.13.23.63.12.72.72.9
Percentage of Revenues ava:RetailElectric ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.00.0

ava:RetailElectric, ava:AvistaUtilities


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value194216209195174213210190177
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax223.90.00.00.0233.80.00.00.00.0
Percentage of Revenues65.352.355.171.562.554.757.867.059.0
Percentage of Revenues ava:RetailElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.0

ava:RetailNaturalGas, ava:AvistaUtilities


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value5112910731501251043142
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax58.70.00.00.067.80.00.00.00.0
Percentage of Revenues17.131.428.311.618.132.228.711.114.1
Percentage of Revenues ava:RetailNaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.0

ava:TransmissionElectric, ava:AvistaUtilities


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value4.8013.4954.1155.9384.4093.7744.724.0584.255.1525.0314.832
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.50.00.00.05.90.00.00.00.00.00.00.0
Percentage of Revenues1.60.81.12.21.61.01.31.41.41.31.41.6
Percentage of Revenues ava:TransmissionElectric ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.0

ava:TransmissionNaturalGas, ava:AvistaUtilities


Revenue
Period End2020-09-302019-09-30
Value1.6561.925
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.0
Percentage of Revenues0.60.7
Percentage of Revenues ava:TransmissionNaturalGas ava:AvistaUtilities0.00.0

ava:TransportationNaturalGas, ava:AvistaUtilities


Revenue
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
Value1.9732.2831.7382.3522.2261.9252.0392.4842.3082.0072.2212.567
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.30.02.30.00.00.00.00.00.00.00.00.0
Percentage of Revenues0.70.60.60.60.60.70.70.60.60.70.70.6
Percentage of Revenues ava:TransportationNaturalGas ava:AvistaUtilities0.00.00.00.00.00.00.00.00.00.00.00.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value298412380272278390364283300396372296319409397297314436402303318418387313337446411301312490447335352482410340343452438343360476374367360456
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.1480.1890.2690.2670.2550.8231.2761.0492.261
Percentage of Revenues0.00.00.10.10.10.20.40.40.8
Percentage of Revenues0.00.00.10.10.10.20.40.40.8
Percentage of Revenues us-gaap:CorporateNonSegment ava:NonUtilityRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, ava:UtilityRevenue


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value298412380272278389363282298
Percentage of Revenues100.0100.099.999.999.999.899.699.699.2
Percentage of Revenues100.0100.099.999.999.999.899.699.699.2
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1012118.8159.997129.8517.798.743
Percentage of Revenues3.53.13.13.23.63.12.72.72.9
Percentage of Revenues3.53.13.13.23.63.12.72.72.9
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AlaskaElectricLightPower100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value287399368263268377353274289
Percentage of Revenues96.496.896.896.796.396.796.996.996.3
Percentage of Revenues96.496.896.896.796.396.796.996.996.3
Percentage of Revenues us-gaap:OperatingSegments ava:UtilityRevenue ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

ava:AlternativeRevenuePrograms, ava:AvistaUtilities


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.209-3.9724.362-4.413-1.4916.0389.725-4.6582.6710.6063.57-5.939
Percentage of Revenues0.1-1.51.6-1.1-0.42.13.2-1.20.70.21.1-1.5
Percentage of Revenues0.1-1.51.6-1.1-0.42.13.2-1.20.70.21.1-1.5
Percentage of Revenues ava:AlternativeRevenuePrograms ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:AlternativeRevenuePrograms, ava:AvistaUtility


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value3.0690.4994.362-4.413
Percentage of Revenues1.00.11.6-1.1
Percentage of Revenues1.00.11.6-1.1
Percentage of Revenues ava:AlternativeRevenuePrograms ava:AvistaUtility100.0100.0100.0100.0

ava:DerivativeRevenues, ava:AvistaUtilities


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value302424311933422438325658
Percentage of Revenues8.18.88.78.05.211.814.06.110.511.117.714.3
Percentage of Revenues8.18.88.78.05.211.814.06.110.511.117.714.3
Percentage of Revenues ava:DerivativeRevenues ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:DerivativeRevenues, ava:AvistaUtility


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value28342431
Percentage of Revenues9.48.58.78.0
Percentage of Revenues9.48.58.78.0
Percentage of Revenues ava:DerivativeRevenues ava:AvistaUtility100.0100.0100.0100.0

ava:OtherRevenues, us-gaap:CorporateAndOther


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
Value0.1480.1890.2260.2640.2510.3090.3920.3180.2370.2510.3750.3140.270.215
Percentage of Revenues0.00.00.10.10.10.10.10.10.10.10.10.10.10.1
Percentage of Revenues0.00.00.10.10.10.10.10.10.10.10.10.10.10.1
Percentage of Revenues ava:OtherRevenues us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:OtherUtilityRevenues, ava:AlaskaElectricLightPower


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.1180.0660.0670.1240.1620.1510.170.1930.1820.1270.150.135
Percentage of Revenues0.00.00.00.00.00.10.10.00.00.00.00.0
Percentage of Revenues0.00.00.00.00.00.10.10.00.00.00.00.0
Percentage of Revenues ava:OtherUtilityRevenues ava:AlaskaElectricLightPower100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:OtherUtilityRevenues, ava:AlaskaElectricLightPowers


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.1080.0890.0670.124
Percentage of Revenues0.00.00.00.0
Percentage of Revenues0.00.00.00.0
Percentage of Revenues ava:OtherUtilityRevenues ava:AlaskaElectricLightPowers100.0100.0100.0100.0

ava:OtherUtilityRevenues, ava:AvistaUtilities


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2.4041.6832.2811.5213.3341.9143.8381.7972.5572.1872.21.961
Percentage of Revenues0.60.60.80.40.90.71.30.50.70.70.70.5
Percentage of Revenues0.60.60.80.40.90.71.30.50.70.70.70.5
Percentage of Revenues ava:OtherUtilityRevenues ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:OtherUtilityRevenues, ava:AvistaUtility


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value2.2392.5782.2811.521
Percentage of Revenues0.80.60.80.4
Percentage of Revenues0.80.60.80.4
Percentage of Revenues ava:OtherUtilityRevenues ava:AvistaUtility100.0100.0100.0100.0

ava:ProvisionforRateRefunds, ava:AlaskaElectricLightPower


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-0.047-0.048-0.047-0.048-0.047-0.048-0.047-0.048-0.048-0.156-0.427-1.122
Percentage of Revenues-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.1-0.1-0.3
Percentage of Revenues-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.1-0.1-0.3
Percentage of Revenues ava:ProvisionforRateRefunds ava:AlaskaElectricLightPower100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:ProvisionforRateRefunds, ava:AlaskaElectricLightPowers


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.048-0.047-0.047-0.048
Percentage of Revenues0.0-0.0-0.0-0.0
Percentage of Revenues0.0-0.0-0.0-0.0
Percentage of Revenues ava:ProvisionforRateRefunds ava:AlaskaElectricLightPowers100.0100.0100.0100.0

ava:ProvisionforRateRefunds, ava:AvistaUtilities


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.1191.7422.08-2.6060.789-0.9272.5122.135-1.3411.940.982-19.822
Percentage of Revenues1.10.60.7-0.70.2-0.30.80.5-0.40.70.3-4.8
Percentage of Revenues1.10.60.7-0.70.2-0.30.80.5-0.40.70.3-4.8
Percentage of Revenues ava:ProvisionforRateRefunds ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:ProvisionforRateRefunds, ava:AvistaUtility


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.3693.1892.08-2.606
Percentage of Revenues0.10.80.7-0.7
Percentage of Revenues0.10.80.7-0.7
Percentage of Revenues ava:ProvisionforRateRefunds ava:AvistaUtility100.0100.0100.0100.0

ava:RevenuefromContractswithCustomers, ava:AlaskaElectricLightPower


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value118.7979.978129.7367.6878.62109.759.5991014
Percentage of Revenues3.13.23.63.12.72.72.92.72.63.23.43.6
Percentage of Revenues3.13.23.63.12.72.72.92.72.63.23.43.6
Percentage of Revenues ava:RevenuefromContractswithCustomers ava:AlaskaElectricLightPower100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RevenuefromContractswithCustomers, ava:AlaskaElectricLightPowers


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value10129.97812
Percentage of Revenues3.53.13.63.1
Percentage of Revenues3.53.13.63.1
Percentage of Revenues ava:RevenuefromContractswithCustomers ava:AlaskaElectricLightPowers100.0100.0100.0100.0

ava:RevenuefromContractswithCustomers, ava:AvistaUtilities


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value330240235351331234231354312242239354
Percentage of Revenues86.988.084.590.191.082.677.089.484.081.874.986.5
Percentage of Revenues86.988.084.590.191.082.677.089.484.081.874.986.5
Percentage of Revenues ava:RevenuefromContractswithCustomers ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RevenuefromContractswithCustomers, ava:AvistaUtility


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value260358235351
Percentage of Revenues87.486.984.590.1
Percentage of Revenues87.486.984.590.1
Percentage of Revenues ava:RevenuefromContractswithCustomers ava:AvistaUtility100.0100.0100.0100.0

ava:RevenuefromContractswithCustomers, us-gaap:CorporateAndOther


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.0430.0030.0040.5140.8840.7312.0247.6476.5216.586.3246.729
Percentage of Revenues0.00.00.00.10.20.30.71.91.82.22.01.6
Percentage of Revenues0.00.00.00.10.20.30.71.91.82.22.01.6
Percentage of Revenues ava:RevenuefromContractswithCustomers us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:StatementBusinessSegments

ava:AlaskaElectricLightPower


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312015-03-312014-12-312014-09-302014-03-312013-12-312013-09-30
Value118.8159.998129.8517.798.743109.8849.57101312129.1570.00.00.0
Percentage of Revenues3.13.23.63.12.72.72.92.72.73.23.33.32.93.03.00.00.00.0
Percentage of Revenues3.13.23.63.12.72.72.92.72.73.23.33.32.93.03.00.00.00.0
Percentage of Revenues ava:AlaskaElectricLightPower100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

ava:AlaskaElectricLightPowers


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value10129.99812
Percentage of Revenues3.53.13.63.1
Percentage of Revenues3.53.13.63.1
Percentage of Revenues ava:AlaskaElectricLightPowers100.0100.0100.0100.0

ava:AvistaUtilities


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value368263268377353274289377355279302388424389282303437395278298431361292293405382302320438337331326
Percentage of Revenues96.896.796.396.796.996.996.395.395.594.494.795.095.094.793.797.189.188.383.084.789.488.285.985.589.887.287.988.991.990.390.390.4
Percentage of Revenues96.896.796.396.796.996.996.395.395.594.494.795.095.094.793.797.189.188.383.084.789.488.285.985.589.887.287.988.991.990.390.390.4
Percentage of Revenues ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:AvistaUtility


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value287399268377
Percentage of Revenues96.496.896.396.7
Percentage of Revenues96.496.896.396.7
Percentage of Revenues ava:AvistaUtility100.0100.0100.0100.0

us-gaap:CorporateAndOther


Revenuesus-gaap:
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.2690.2670.2550.8231.2761.0492.2617.8986.8966.8946.5946.944
Percentage of Revenues0.10.10.10.20.40.40.82.01.92.32.11.7
Percentage of Revenues0.10.10.10.20.40.40.82.01.92.32.11.7
Percentage of Revenues us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Unregulated Operating Revenue

us-gaap:UnregulatedOperatingRevenue

us-gaap:UnregulatedOperatingRevenue


Unregulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.1480.1890.2690.2670.2550.8231.2761.0492.2617.8986.8966.8946.5946.944
Percentage of UnregulatedOperatingRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.00.00.10.10.10.20.40.40.82.01.92.32.11.7

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value66466399640262836302617360825964587758895782555755015485551454525373534053095215506949564906473946794689471243364202431643614402434743324313419042164254421439683842382339403606
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidatedEntities, us-gaap:CounterpartyName, us-gaap:OtherCommitments

us-gaap:VariableInterestEntityNotPrimaryBeneficiary, ava:LimitedPartnershipsAndSimilarEntities, ava:VIECommitments


Assetsus-gaap:
Period End2020-12-31
Value51
Percentage of Assets0.8
Percentage of Assets0.8
Percentage of Assets us-gaap:VariableInterestEntityNotPrimaryBeneficiary ava:LimitedPartnershipsAndSimilarEntities ava:VIECommitments100.0

us-gaap:Assets us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value-13.337-12.677-11.872-11.947-14.771-19.011-15.595-17.324-28.288-17.865-35.528-25.885-26.675-22.951-15.0750.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets-0.2-0.2-0.2-0.2-0.2-0.3-0.3-0.3-0.5-0.3-0.6-0.5-0.5-0.4-0.30.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets-0.2-0.2-0.2-0.2-0.2-0.3-0.3-0.3-0.5-0.3-0.6-0.5-0.5-0.4-0.30.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Assets us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312018-12-31
Value11611010910811111387
Percentage of Assets1.81.71.71.71.81.91.5
Percentage of Assets1.81.71.71.71.81.91.5
Percentage of Assets us-gaap:CorporateNonSegment ava:NonUtilityRevenue100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, ava:UtilityRevenue


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312018-12-31
Value6542630263046186620559845731
Percentage of Assets98.498.598.598.598.598.499.1
Percentage of Assets98.498.598.598.598.598.499.1
Percentage of Assets us-gaap:OperatingSegments ava:UtilityRevenue100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312018-12-31
Value270270268269273271272
Percentage of Assets4.14.24.24.34.34.54.7
Percentage of Assets4.14.24.24.34.34.54.7
Percentage of Assets us-gaap:OperatingSegments ava:UtilityRevenue ava:AlaskaElectricLightPower100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312018-12-31
Value6272603160355916593257135458
Percentage of Assets94.494.294.394.294.193.994.4
Percentage of Assets94.494.294.394.294.193.994.4
Percentage of Assets us-gaap:OperatingSegments ava:UtilityRevenue ava:AvistaUtilities100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:CounterpartyName

ava:LimitedPartnershipsAndSimilarEntities


Assetsus-gaap:
Period End2020-12-31
Value56
Percentage of Assets0.9
Percentage of Assets0.9
Percentage of Assets ava:LimitedPartnershipsAndSimilarEntities100.0

Liabilities

us-gaap:Liabilities

us-gaap:Liabilities


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value45764330437243004327421441434071399340214008380737393726378437813686365436613586345233663378323131653182322928442792294930273083302530193031290629462988297627462622262127682521
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets68.967.768.368.468.768.368.168.367.968.369.368.568.067.968.669.468.668.469.068.868.167.968.968.267.667.968.565.666.568.369.470.069.669.770.369.469.970.370.669.268.368.570.369.9

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value66466399640262836302617360825964587758895782555755015485551454525373534053095215506949564906473946794689471243364202431643614402434743324313419042164254421439683842382339403606
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-31
Value2069206820291982197519591939189318841867177317491762175817291670168616851648162816161589152815081514150614831491140913511318131013141304127712771216120711851170116711601125110510851051
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.132.331.731.631.331.731.931.732.131.730.731.532.032.131.430.631.431.631.031.231.932.131.131.832.432.131.534.433.531.330.229.830.230.129.630.528.828.428.129.530.430.328.60.00.029.1

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value361350343299352274305247269364346245259309337316320357351284268279306257289310395265442504549485468507505516555607614548455465579418
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.45.55.44.85.64.45.04.24.66.26.04.44.75.66.15.86.06.76.65.55.35.66.25.46.26.68.46.110.511.712.611.010.811.711.712.313.214.314.613.811.812.214.711.6

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value39211484116189.89614171414213526161413268.5077.0841312109.314162222102079082918589758293727478696169563839372411
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.30.21.31.80.30.20.20.30.30.30.40.60.50.30.30.20.50.20.10.30.30.20.20.30.50.50.24.92.11.92.12.02.11.72.02.21.71.82.01.81.61.80.00.00.01.00.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue us-gaap:FairValueByAssetClass

us-gaap:FixedIncomeSecurities


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value0.10.20.50.50.40.4
Percentage of CashAndCashEquivalentsAtCarryingValue0.30.93.50.60.34.0
Percentage of Assets0.00.00.00.00.00.0
Percentage of Assets us-gaap:FixedIncomeSecurities0.00.00.00.00.00.0

Inventory Net

us-gaap:InventoryNet

us-gaap:InventoryNet


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value8263676967566667676163625649586561475358514354595043666949324456453047515136526447384837
Percentage of InventoryNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.21.01.11.11.10.91.11.11.21.01.11.11.00.91.11.21.10.91.01.11.00.91.11.31.10.91.41.61.20.81.01.31.00.71.11.21.20.91.21.61.21.01.21.0

Inventory Raw Materials And Supplies

us-gaap:InventoryRawMaterialsAndSupplies

us-gaap:InventoryRawMaterialsAndSupplies


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value57565350484947464647474544434141414240393838373435333231312928292926262424
Percentage of InventoryRawMaterialsAndSupplies100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.90.90.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.80.70.70.70.70.70.70.70.70.70.70.60.60.60.6

Other Assets Current

us-gaap:OtherAssetsCurrent

us-gaap:OtherAssetsCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value8382842642304036306054352244524662584935393729394343453838445739343924312826493427292115
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.31.31.30.40.70.50.70.60.51.00.90.60.40.80.90.81.21.10.90.70.80.70.60.80.90.91.00.90.91.01.30.90.80.90.60.80.70.61.20.90.70.80.60.4

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value71657059698568866809671066276520645463686370624061516047601158815786570256565552549153935331520051155007494548604576449844504389431842494197411140564001396639003841379237753609
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets107.8110.3109.1109.6108.0108.7109.0109.3109.8108.1110.2112.3111.8110.2109.0107.9107.7106.8106.5106.5108.3108.8108.7109.7109.3106.8105.0112.1108.9104.2102.099.799.398.197.398.196.294.194.198.3100.099.295.8100.1

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PublicUtility, us-gaap:StatementBusinessSegments

us-gaap:Electricity, ava:AlaskaElectricLightPower


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value159156221218
Percentage of PropertyPlantAndEquipmentGross2.32.43.53.6
Percentage of Assets2.52.63.84.0
Percentage of Assets us-gaap:Electricity ava:AlaskaElectricLightPower0.00.00.00.0

us-gaap:Electricity, ava:AvistaUtilities


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value4683444542554057
Percentage of PropertyPlantAndEquipmentGross67.067.166.867.5
Percentage of Assets73.273.173.673.6
Percentage of Assets us-gaap:Electricity ava:AvistaUtilities0.00.00.00.0

us-gaap:NaturalGasUsRegulated, ava:AvistaUtilities


Property
Period End2020-12-312019-12-312018-12-312017-12-31
Value1419133512431137
Percentage of PropertyPlantAndEquipmentGross20.320.119.518.9
Percentage of Assets22.222.021.520.6
Percentage of Assets us-gaap:NaturalGasUsRegulated ava:AvistaUtilities0.00.00.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:StatementBusinessSegments

ava:AlaskaElectricLightPower


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value169165229227221206195
Percentage of PropertyPlantAndEquipmentGross2.42.53.63.83.93.93.9
Percentage of Assets2.72.74.04.14.24.24.1
Percentage of Assets ava:AlaskaElectricLightPower0.00.00.00.00.00.073.9

ava:AvistaUtilities


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value6815646261405783543451254750
Percentage of PropertyPlantAndEquipmentGross97.697.596.496.296.196.196.1
Percentage of Assets106.5106.2106.2104.9102.4104.5100.8
Percentage of Assets ava:AvistaUtilities0.00.00.00.00.00.0108.8

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap:StatementBusinessSegments

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:CorporateAndOther


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value2.25.41211111010
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.10.20.20.20.20.2
Percentage of Assets us-gaap:CorporateAndOther0.00.00.00.00.00.00.0

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value525252525252525252525757575757575757575757575757575757555.246767676767675737373392626252524
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.80.80.80.80.80.90.90.90.91.01.01.01.11.01.11.11.11.11.11.11.21.21.21.21.21.21.30.11.81.71.71.81.81.81.81.71.70.90.70.70.70.70.7

us-gaap:Goodwill us-gaap:StatementBusinessSegments

ava:AlaskaElectricLightPower


Goodwillus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312015-09-302015-06-302014-12-312014-07-012013-12-31
Value525252525252525252520.0
Percentage of Goodwill100.0100.090.990.990.990.990.990.991.00.00.0
Percentage of Assets0.80.90.91.01.01.11.11.11.10.00.0
Percentage of Assets ava:AlaskaElectricLightPower0.00.00.00.00.00.00.00.020.00.00.0

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value707171717265697070700.0
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets1.11.11.11.11.21.11.11.21.21.20.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value192726292525232120222316015314914814514113514814214314014314615115210022524025425624924824925226321218619121195137
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.30.40.40.50.40.40.40.40.30.40.42.92.82.72.82.72.72.62.92.92.93.03.13.13.23.52.45.25.55.85.95.85.86.06.06.25.04.75.00.65.03.8

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi

us-gaap:EquitySecuritiesFvNi


Equity
Period End2021-06-302021-03-312020-12-312019-12-31
Value69615951
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.0
Percentage of Assets1.11.00.90.8

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value10493106831108811091801091088076671077269721158163591146370621128273163182158153161198140148134166154128150171160
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.61.51.71.31.81.41.81.51.41.91.91.51.41.21.91.31.31.42.21.61.21.22.31.31.51.32.41.91.73.84.23.63.53.74.63.43.53.24.03.93.43.94.44.5

Accrued Liabilities Current

us-gaap:AccruedLiabilitiesCurrent

us-gaap:AccruedLiabilitiesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3828353027273530293332273133
Percentage of AccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.40.50.50.40.40.60.50.50.60.60.50.60.6

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value891492505474656565530399516566639346289669697673682366407341501431474447306325385270464570625550582579576547584605627576454454579503
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets13.47.77.97.610.49.28.76.78.89.611.16.25.312.212.612.312.76.97.76.69.98.79.79.46.66.98.26.211.013.214.312.513.413.413.413.113.914.214.914.511.811.914.714.0

Long Term Debt Current

us-gaap:LongTermDebtCurrent

us-gaap:LongTermDebtCurrent


Long
Period End2021-06-302020-09-302020-06-302019-12-312012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value2505252527.4097.4747.377.3630.360.35835
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.80.80.80.90.20.20.20.20.00.01.0

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


Operating
Period End2020-12-312019-12-312019-03-312018-12-31
Value4249000.04128000.04120000.00
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.00.0
Percentage of Assets0.10.10.10.0

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value171161149140123174130130124175120133121836461646570164177178147146131160141128123180145145151184142147130149141139109119110106
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.62.52.32.22.02.82.22.22.13.02.12.42.21.51.21.11.21.21.33.13.53.63.03.12.83.43.03.02.94.23.33.33.54.33.33.53.13.53.43.52.83.12.83.0

Long Term Debt

us-gaap:LongTermDebt us-gaap:LongtermDebtType

us-gaap:LongTermDebt

ava:FutureLongTermDebtMaturitiesIncludingLongTermDebtToAffiliatedTrusts


Long
Period End2020-12-312011-12-31
Value20751235
Percentage of LongTermDebt100.0100.0
Percentage of Assets32.429.3
Percentage of Assets ava:FutureLongTermDebtMaturitiesIncludingLongTermDebtToAffiliatedTrusts0.00.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1758200820082009184418431170116910841094110111011036
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets26.531.431.432.029.330.327.527.827.328.528.828.028.7

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value620607594550540525528
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets9.39.59.38.88.68.58.7

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value18819921119920420721221021421822219119520020321621922322620220220220118818818818995103113122252263274283214225235246162169157161123
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.83.13.33.23.23.43.53.53.73.73.83.43.53.63.74.04.14.24.33.94.04.14.14.04.04.04.02.22.52.62.85.76.16.36.65.15.35.55.84.14.44.14.13.4

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value1081139694
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent51.253.743.446.4
Percentage of Assets1.71.91.71.7
Percentage of Assets us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.0

us-gaap:PensionPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value10298126109
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent48.646.656.753.7
Percentage of Assets1.61.62.22.0
Percentage of Assets us-gaap:PensionPlansDefinedBenefit0.00.00.00.0

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value18218621424025123720122921119571696914714315816216815313516517416116514614914612011411913012212210611010510411011691929610952
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.72.93.43.84.03.83.33.83.63.31.21.21.32.72.62.93.03.22.92.63.33.53.33.53.13.23.12.82.72.83.02.82.82.52.62.52.52.62.82.32.42.52.81.5

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value686867707062656868670.0
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets1.01.11.11.11.11.01.11.21.21.10.0

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2020-12-312019-12-31
Value4799000.04375000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0100.0
Percentage of Assets0.10.1

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2020-12-312019-12-31
Value4827000.04383000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0100.0
Percentage of Assets0.10.1

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2020-12-312019-12-31
Value4852000.04399000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0100.0
Percentage of Assets0.10.1

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-312019-12-31
Value4865000.04411000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0100.0
Percentage of Assets0.10.1

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-312019-12-31
Value9691
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0
Percentage of Assets1.51.5

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2020-12-312019-12-312019-09-302019-06-30
Value71697372
Percentage of OperatingLeaseLiability100.0100.0100.0100.0
Percentage of Assets1.11.11.21.2

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2020-12-312019-12-31
Value120113
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0100.0
Percentage of Assets1.91.9

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2020-12-312019-12-31
Value4843
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0100.0
Percentage of Assets0.80.7

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-31
Value2069206820291982197519591939189318841867177317491762175817291670168616851648162816161589152815081514150614831491140913511318131013141304127712771216120711851170116711601125110510851051
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.132.331.731.631.331.731.931.732.131.730.731.532.032.131.430.631.431.631.031.231.932.131.131.832.432.131.534.433.531.330.229.830.230.129.630.528.828.428.129.530.430.328.60.00.029.1

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-03-312009-12-312008-12-31
Value206920682029198219751959193918931884186817741750176217581730167016871685164816281617158915281508151415071483149214101330129812891293128312591259121612081185117011681159112510621050996
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.132.331.731.631.331.731.931.732.131.730.731.532.032.131.430.631.431.631.131.231.932.131.231.832.432.131.534.433.630.829.829.329.829.629.230.128.928.428.129.530.430.328.60.029.10.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value-13.755-14.063-14.378-9.614-9.834-10.054-10.259-7.383-7.545-7.706-7.866-9.22-9.424-9.628-8.09-7.02-7.202-7.385-7.568-7.599-7.739-7.879-6.65-7.151-7.397-7.642-7.888-3.898-4.01-4.925-5.819-7.848-7.636-6.587-6.7-4.897-5.158-5.426-5.637-4.339-4.462-4.522-4.326-2.242-2.278-2.314-2.35-6.092-19.608
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-0.7-0.7-0.7-0.5-0.5-0.5-0.5-0.4-0.4-0.4-0.4-0.5-0.5-0.5-0.5-0.4-0.4-0.4-0.5-0.5-0.5-0.5-0.4-0.5-0.5-0.5-0.5-0.3-0.3-0.4-0.4-0.6-0.6-0.5-0.5-0.4-0.4-0.4-0.5-0.4-0.4-0.4-0.40.00.0-0.2-0.2-0.60.0
Percentage of Assets-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.2-0.1-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.10.00.00.0-0.10.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value13031285128612651234120912101186115711401136113511341131113310771075107310751073105210321004100210019989991007885899896898895891889887861857855848842833827815788779778774726
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest63.062.263.463.862.561.762.462.761.461.064.164.964.464.365.564.563.863.765.265.965.164.965.766.566.166.367.467.562.867.669.169.769.269.570.670.570.871.072.172.572.171.973.60.00.073.474.177.70.0
Percentage of Assets19.620.120.120.119.619.619.919.919.719.419.720.420.620.620.619.820.020.120.320.620.820.820.521.221.421.321.223.221.120.820.620.420.620.620.621.220.420.220.321.421.921.821.00.00.00.021.60.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value780796758727749759738714734734644623637636604600618619581562572565530512520515491488528436407399406398376377360355336326330331302293299285274227206
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest37.738.537.336.738.038.838.137.739.039.336.335.636.236.234.935.936.736.835.234.635.435.634.734.034.434.233.132.737.532.831.430.931.431.129.929.929.729.528.427.928.328.626.90.00.026.926.222.90.0
Percentage of Assets11.712.411.811.611.912.312.112.012.512.511.111.211.611.611.011.011.511.610.910.811.311.410.810.811.111.010.411.312.610.19.39.19.39.28.79.08.68.48.08.28.68.77.70.00.00.07.60.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value13031285128612651234120912101186115711401136113511341131113310771075107310751073105210321004100210019989991007885899896898895891889887861857855848842833827778
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets19.620.120.120.119.619.619.919.919.719.419.720.420.620.620.619.820.020.120.320.620.820.820.521.221.421.321.223.221.120.820.620.420.620.620.621.220.420.220.321.421.921.821.021.6

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value780796758727749759738714734734644623637636604600618619581562572565530512520515491488528436407399406398376377360355336326330331302274
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets11.712.411.811.611.912.312.112.012.512.511.111.211.611.611.011.011.511.610.910.811.311.410.810.811.111.010.411.312.610.19.39.19.39.28.79.08.68.48.08.28.68.77.77.6

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value-13755000.0-14063000.0-14378000.0-9614000.0-9834000.0-10054000.0-10259000.0-7383000.0-7545000.0-7706000.0-7866000.0-9220000.0-9424000.0-9628000.0-8090000.0-7020000.0-7202000.0-7385000.0-7568000.0-7599000.0-7739000.0-7879000.0-6650000.0-7151000.0-7397000.0-7642000.0-7888000.0-3898000.0-4010000.0-4925000.0-5819000.0-7848000.0-7636000.0-6587000.0-6700000.0-4897000.0-5158000.0-5426000.0-5637000.0-4339000.0-4462000.0-4522000.0-4326000.0-2350000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.2-0.2-0.1-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value150.0651729230.1752027140.19-1.224-0.0030.9950.232530.2430.9320.315-1.489192027-1.3970.3170.6670.413-153.5011511.3420.638-4.4791.4621.8681.149-5.316252.1381.437-2.0035.3387.428.4587.93259.1350.375
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:CommonStock


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.7880.8592.0330.8241.8740.8042.1421.9312.0434.4520.9651.2421.761.7981.4752.4961.6370.9221.6031.7541.7411.9671.4561.4981.5681.5131.6151.2963.1461.6191.5121.5221.5071.4612.3621.1131.1211.120.9170.9140.9150.8890.7890.790.7890.729
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value44145488264135578755196-3.919090184102787814910498501056479851461.554416715640465010559577812129766010326863381
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues15.135.112.730.323.234.715.830.918.549.7-1.130.528.445.125.826.625.134.325.932.415.825.216.625.225.332.90.413.821.532.09.013.914.321.814.416.922.826.86.622.416.721.77.123.79.417.8

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-114.378-96.461-109.738-109.241-96.633-95.131-125.196-130.282-92.369-97.664-132.745-114.782-105.551-87.354-131.752-112.762-99.662-89.927-117.513-108.329-114.97-91.654-116.725-95.513-95.414-80.175-96.977-73.997127-60.697-78.659-78.654-68.218-86.686-65.603-46.556-28.193-154.316-114.57-103.732-64.1380.159-100.812-67.194-37.883-47.334
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-38.3-23.4-28.8-40.1-34.7-24.4-34.3-45.9-30.7-24.6-35.7-38.8-33.1-21.3-33.1-38.0-31.7-20.6-29.2-35.7-36.1-21.9-30.1-30.5-28.3-18.0-23.5-24.540.9-12.4-17.6-23.4-19.4-18.0-16.0-13.7-8.2-34.1-26.1-30.2-17.80.0-26.9-18.3-10.5-10.4

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value86-41.178-9.289-5.046129-31.12623937-97.9861301023-87.3230358.082-42.116143.72465-11.61539.4534.241-66.665107-165.305-77.23-88.603293814-4.96-1.03-21.599-29.51231823412-110.99786-1.5533.054-31.152
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues29.1-10.0-2.4-1.946.5-8.017.314.012.6-24.735.03.57.5-21.37.611.82.6-9.63.71.220.5-2.813.83.01.3-14.926.0-54.8-24.7-18.06.511.54.0-1.0-0.3-6.3-8.66.918.710.23.3-23.323.2-0.40.8-6.8

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value177.451-70.551-31.647979.023-4.558-2.777
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues5.81.8-18.5-11.635.02.3-1.3-1.0

Amortization Of Financing Costs

us-gaap:AmortizationOfFinancingCosts

us-gaap:AmortizationOfFinancingCosts


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value748000.0823000.0908000.0964000.0712000.0653000.0672000.0670000.0669000.0669000.0640000.0692000.0820000.0815000.0814000.0813000.0814000.0813000.0882000.0853000.0866000.0876000.0875000.0877000.0879000.0895000.0893000.0910000.0936000.0953000.0972000.0946000.0948000.0947000.0927000.0950000.0961000.0965000.01431000.0969000.0981000.01236000.01200000.01033000.01130000.01051000.0
Percentage of AmortizationOfFinancingCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DeferredIncomeTaxExpenseBenefit


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value5.1195.966476.2-1.635-6.7654.8794.642-3.3068.883-2.005113.777-5.0491122181737302234396.226.243-0.0823287221.4537.0217-2.5241.123.069116.825-0.303-6.776254.1920.966272.154.1854.155
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value56555454645151505549474746454444434342414040383736353534333434333331333131302928282728262626
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value10-2.59136.532-10.333-19.5271511-36.0916155.250.355-21.99721-0.557-9.196-20.2392214-0.68-30.80424-5.9824.149-30.5459.88811-22.96-11.065153.35-6.328-20.77840-7.32712-16.112-6.03827-22.36-16.6742321-22.802-9.174
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value19-4.291-1.5761.69310-9.901-1.150.0736.8310.3941.1165.8657.641-8.815-7.8864.77414-6.129-3.0986.4427.753-10.263188.8637.087-22.571-3.5851816-12.141-11.8971115-17.137-3.61-0.07214-15.652-12.872179.287-10.222-7.8982.96721-5.602
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value44145488264135578755196-3.919090184102787814910498501056479851461.554416715640465010559577812129766010326863381
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues15.135.112.730.323.234.715.830.918.549.7-1.130.528.445.125.826.625.134.325.932.415.825.216.625.225.332.90.413.821.532.09.013.914.321.814.416.922.826.86.622.416.721.77.123.79.417.8

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1468584.8761748505.092511545102554274.4512162401227563813254632101004831112542155.78618382410234125122528
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.716.515.41.86.312.413.91.88.429.212.33.48.013.46.91.56.914.210.04.08.513.49.94.17.510.47.83.532.39.97.13.47.38.83.91.75.38.55.63.16.48.86.93.47.16.3

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1468584.8761748505.092511545102554274.4512162401228563813254632101004831112542155.78618382410234125122528
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0105.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues4.716.515.41.86.312.413.91.88.429.212.33.48.013.46.91.56.914.210.04.09.013.49.94.17.510.47.83.532.39.97.13.47.38.83.91.75.38.55.63.16.48.86.93.47.16.3
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value584.8761748505.092511545102554274.4582162401227563813254632101004831112543165.96218382511234226132629
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues15.41.86.312.413.91.88.329.212.33.48.013.46.91.56.914.210.04.08.613.410.04.27.510.47.83.532.210.07.03.67.38.93.91.85.48.45.93.46.58.97.03.67.26.4

Share Based Compensation

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value1.6540.6262.1410.8791.9540.8722.4021.9422.1644.8450.1521.3371.9151.9631.553.1661.8110.8321.632.0251.9232.3131.6511.8221.7341.7071.8531.4233.2871.5511.51.6381.6161.4641.2531.3811.541.618
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-114.378-96.461-109.738-109.241-96.633-95.131-125.196-130.282-92.369-97.664-132.745-114.782-105.551-87.354-131.752-112.762-99.662-89.927-117.513-108.329-114.97-91.654-116.725-95.513-95.414-80.175-96.977-73.997127-60.697-78.659-78.654-68.218-86.686-65.603-46.556-28.193-154.316-114.57-103.732-64.1380.159-100.812-67.194-37.883-47.334
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-38.3-23.4-28.8-40.1-34.7-24.4-34.3-45.9-30.7-24.6-35.7-38.8-33.1-21.3-33.1-38.0-31.7-20.6-29.2-35.7-36.1-21.9-30.1-30.5-28.3-18.0-23.5-24.540.9-12.4-17.6-23.4-19.4-18.0-16.0-13.7-8.2-34.1-26.1-30.2-17.80.0-26.9-18.3-10.5-10.4

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1169710610893951211201069312811310181124110908611810593881209596819593765973757470925762577070494964573742
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value86-41.178-9.289-5.046129-31.12623937-97.9861301023-87.3230358.082-42.116143.72465-11.61539.4534.241-66.665107-165.305-77.23-88.603293814-4.96-1.03-21.599-29.51231823412-110.99786-1.5533.054-31.152
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues29.1-10.0-2.4-1.946.5-8.017.314.012.6-24.735.03.57.5-21.37.611.82.6-9.63.71.220.5-2.813.83.01.3-14.926.0-54.8-24.7-18.06.511.54.0-1.0-0.3-6.3-8.66.918.710.23.3-23.323.2-0.40.8-6.8

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:ProceedsFromIssuanceOfLongTermDebt


Proceeds
Period End2020-12-312019-12-312019-09-302018-12-312018-09-302017-12-312017-09-302016-12-312015-12-312014-12-312013-12-312012-12-31
Value0.01800.00.00.0900.0175100750.080
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0100.00.00.00.0100.00.0100.0100.0100.00.0100.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.7320.7590.6980.7310.70.6650.6650.6650.6342733.0370.8220.8220.8210.82270900.7910.7920.7310.760.7750.6390.604390.080.069500.0560.2580.1010.1290.099110.0650.0930.0150.0940.095100100.0860.059
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Payments Of Dividends

us-gaap:PaymentsOfDividends

us-gaap:PaymentsOfDividends


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value29292727272726252525242424242323232321212121202020201920191918181818171717171615151514131313
Percentage of PaymentsOfDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:EffectiveIncomeTaxRateContinuingOperations


Effective
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value14.615.23.215.0-0.830.15-0.024-0.026-0.0750.206-0.0010.1330.1690.1630.0480.5360.3750.3490.0030.383
Percentage of EffectiveIncomeTaxRateContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Liabilities

us-gaap:DeferredTaxLiabilities

us-gaap:DeferredTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value594528487466840747695510489677624
Percentage of DeferredTaxLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value307198218226207187131136201201157
Percentage of DeferredTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value101613107.9462.8628.145
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0

Proceeds From Repayments Of Short Term Debt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value103-10.053-171.0136-0.8-21.23850-71.015535-50.0-55.398-90.05931-15.070-15.0-25.04025-40.070-116.540-60.0105-29.5430.5-30.0-9.054-24.0-35.52110.0-45.0
Percentage of ProceedsFromRepaymentsOfShortTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:AdjustmentInDecouplingRegulatoryDeferral

ava:AdjustmentInDecouplingRegulatoryDeferral


Adjustment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value-2.8850.6820.369-3.7944.609-4.155-1.2136.096
Percentage of AdjustmentInDecouplingRegulatoryDeferral100.0100.0100.0100.0100.0100.0100.0100.0

ava:DeferredIncrementalBadDebtExpense us-gaap:UnusualOrInfrequentItem

ava:DeferredIncrementalBadDebtExpense

ava:COVID19


Deferred
Period End2020-12-31
Value4600000.0
Percentage of DeferredIncrementalBadDebtExpense100.0

ava:DepreciationAndAmortizationExpense

ava:DepreciationAndAmortizationExpense


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value565554546451515055494646454443434242414039393736353434333134343333313331313029282827282626
Percentage of DepreciationAndAmortizationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:DepreciationAndAmortizationExpense us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.0730.1270.1470.1460.1880.2350.1310.1340.155
Percentage of DepreciationAndAmortizationExpense0.10.20.30.30.30.50.30.30.3

us-gaap:OperatingSegments, ava:UtilityRevenue


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value565554536351505055
Percentage of DepreciationAndAmortizationExpense99.999.899.799.799.799.599.799.799.7

ava:DepreciationAndAmortizationExpense us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value2.4972.4972.4582.4542.4462.4472.4312.4212.409
Percentage of DepreciationAndAmortizationExpense4.44.54.54.53.84.74.84.84.3

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value535251516148484753
Percentage of DepreciationAndAmortizationExpense95.495.395.295.295.994.895.094.995.4

ava:EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalAmount

ava:EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalAmount


Effective
Period End2020-12-312020-09-302020-06-302019-12-312019-09-302019-06-30
Value008390000.069000.020000.05091000.0
Percentage of EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalAmount0.00.0100.0100.0100.0100.0

ava:EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalPercent

ava:EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalPercent


Effective
Period End2020-12-312020-09-302020-06-302019-12-312019-09-302019-06-30
Value5.6-11.673-0.883.175-0.4-0.219
Percentage of EffectiveIncomeTaxRateReconciliationExcessDeferredIncomeTaxReversalPercent100.0100.0100.0100.0100.0100.0

ava:EnergyCommodityDerivativeExpectedToBeSettleYearFive us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

ava:EnergyCommodityDerivativeExpectedToBeSettleYearFive

ava:GasDerivative, ava:Physical, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value01115000.01115000.0000
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearFive0.0100.0100.00.00.00.0

ava:EnergyCommodityDerivativeExpectedToBeSettleYearFour us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

ava:EnergyCommodityDerivativeExpectedToBeSettleYearFour

ava:GasDerivative, ava:Financial, ava:Purchase


Energy
Period End2020-09-302020-06-302020-03-31
Value1.80.90.0
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearFour100.0100.00.0

ava:GasDerivative, ava:Physical, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.01.370.00.0
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearFour0.00.00.00.0

ava:EnergyCommodityDerivativeExpectedToBeSettleYearOne us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

ava:EnergyCommodityDerivativeExpectedToBeSettleYearOne

ava:ElectricDerivative, ava:Financial, ava:Purchase


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-0.030.092-0.038-0.067-0.0660.395
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne100.0100.0100.0100.0100.0100.0

ava:ElectricDerivative, ava:Financial, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-0.3760.7540.042-0.393-0.6891.491
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne1253.3819.6-110.5586.61043.9377.5

ava:ElectricDerivative, ava:Physical, ava:Purchase


Energy
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.0080.0030.0260.003
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne-26.73.3-39.40.8

ava:ElectricDerivative, ava:Physical, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.0070.04-0.021-0.033-0.2950.366
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne-23.343.555.349.3447.092.7

ava:GasDerivative, ava:Financial, ava:Purchase


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-10.6154832-21.83-6.7761
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne35383.352204.3-85415.832582.110257.615526.6

ava:GasDerivative, ava:Financial, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-6.5772926-8.81-5.57527
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne21923.332087.0-70060.513149.38447.06844.3

ava:GasDerivative, ava:Physical, ava:Purchase


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-1.5597.4341.851-0.823-0.90710
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne5196.78080.4-4871.11228.41374.22590.4

ava:GasDerivative, ava:Physical, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-3.5418.0453.310.6970.570.871
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearOne11803.38744.6-8710.5-1040.3-863.6220.5

ava:EnergyCommodityDerivativeExpectedToBeSettleYearThree us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

ava:EnergyCommodityDerivativeExpectedToBeSettleYearThree

ava:GasDerivative, ava:Financial, ava:Purchase


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value5.086.92-12.135.783.487.82
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearThree100.0100.0100.0100.0100.0100.0

ava:GasDerivative, ava:Financial, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value4.191.97-5.121.521.82.7
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearThree82.528.542.226.351.734.5

ava:GasDerivative, ava:Physical, ava:Purchase


Energy
Period End2020-09-302020-06-302020-03-31
Value0.00.00.45
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearThree0.00.05.8

ava:GasDerivative, ava:Physical, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.01.360.00.0
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearThree0.019.70.00.0

ava:EnergyCommodityDerivativeExpectedToBeSettleYearTwo us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:IncomeStatementLocation

ava:EnergyCommodityDerivativeExpectedToBeSettleYearTwo

ava:ElectricDerivative, ava:Financial, ava:Purchase


Energy
Period End2020-09-302020-06-302020-03-31
Value0.00.00.123
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearTwo0.00.0100.0

ava:ElectricDerivative, ava:Financial, us-gaap:Sales


Energy
Period End2020-09-302020-06-302020-03-31
Value0.0610.00.246
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearTwo0.00.0200.0

ava:GasDerivative, ava:Financial, ava:Purchase


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value8.4929-28.938.031432
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearTwo0.00.00.00.00.026113.8

ava:GasDerivative, ava:Financial, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value7.8712-22.683.9659.04521
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearTwo0.00.00.00.00.017642.3

ava:GasDerivative, ava:Physical, ava:Purchase


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.00.45-5.930.95.1750.305
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearTwo0.00.00.00.00.0248.0

ava:GasDerivative, ava:Physical, us-gaap:Sales


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.91.36-1.480.90.451.49
Percentage of EnergyCommodityDerivativeExpectedToBeSettleYearTwo0.00.00.00.00.01211.4

ava:FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssets us-gaap:FairValueByFairValueHierarchyLevel

ava:FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssets

us-gaap:FairValueInputsLevel3


Fair
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-3359000.0-1046000.0-391000.0485000.0159000.0-133000.0625000.07959000.04286000.0912000.01829000.0-1660000.01212000.0-2222000.0-644000.0-2671000.04068000.0-2052000.02841000.0-4150000.0-2234000.0-2735000.0-1506000.0-5431000.0-11107000.0-3980000.05087000.04222000.01777000.05800000.0-4611000.01054000.0-2208000.0-7644000.05978000.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssets us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass

us-gaap:FairValueInputsLevel3, ava:NaturalGasExchangeAgreements


Fair
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-30
Value268000.03220000.0-3359000.0-1046000.0-391000.0485000.0160000.0-133000.0-829000.08977000.0415000.0476000.0-768000.0203000.0617000.0-195000.02012000.0336000.0-1551000.0-1745000.01800000.0-8163000.0777000.0712000.0235000.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssets0.00.0100.0100.0100.0100.0100.6100.0-132.6112.89.752.2-42.0-12.2-27.830.3-75.3-16.4-54.642.0-65.8542.0-14.3-17.94.6

ava:IncomeTaxReconciliationSettlementOfShareBasedCompensationAmount

ava:IncomeTaxReconciliationSettlementOfShareBasedCompensationAmount


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-30
Value21000.0-930000.000-165000.000
Percentage of IncomeTaxReconciliationSettlementOfShareBasedCompensationAmount100.0100.00.00.0100.00.00.0

ava:IncomeTaxReconciliationSettlementOfShareBasedCompensationPercent

ava:IncomeTaxReconciliationSettlementOfShareBasedCompensationPercent


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-30
Value0.1-1.1-0.1990-0.3-0.3960
Percentage of IncomeTaxReconciliationSettlementOfShareBasedCompensationPercent100.0100.0100.00.0100.0100.00.0

ava:InterestExpenseExcludingInterestExpenseToRelatedParty

ava:InterestExpenseExcludingInterestExpenseToRelatedParty


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value262626252526252525
Percentage of InterestExpenseExcludingInterestExpenseToRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:InterestExpenseIncludingAffiliatedTrusts

ava:InterestExpenseIncludingAffiliatedTrusts


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value262626252526262625262524252524242323222121212020192019181819191919191919191918181818181919
Percentage of InterestExpenseIncludingAffiliatedTrusts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:InterestExpenseIncludingAffiliatedTrusts us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.025-0.041-0.025-0.029-0.047-0.086-0.106-0.186-0.197-0.44-0.368-0.313-0.234-0.165-0.077-0.071-0.027-0.014-0.016-0.019-0.034-0.063-0.051-0.029-0.03-0.022-0.054-0.163-0.079-0.088
Percentage of InterestExpenseIncludingAffiliatedTrusts0.1-0.2-0.1-0.1-0.2-0.3-0.4-0.7-0.8-1.7-1.4-1.3-0.9-0.7-0.3-0.3-0.1-0.1-0.1-0.1-0.2-0.3-0.3-0.1-0.2-0.1-0.3-0.9-0.4-0.5

ava:InterestExpenseIncludingAffiliatedTrusts us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.1310.1290.1310.1310.130.1310.1470.1490.148
Percentage of InterestExpenseIncludingAffiliatedTrusts0.50.50.50.50.50.50.60.60.6

us-gaap:OperatingSegments, ava:UtilityRevenue


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value262626252526262625
Percentage of InterestExpenseIncludingAffiliatedTrusts99.699.799.699.699.799.899.8100.1100.2

ava:InterestExpenseIncludingAffiliatedTrusts us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.5231.5251.5631.5611.5611.5891.5981.5961.595
Percentage of InterestExpenseIncludingAffiliatedTrusts5.85.85.96.06.06.06.16.16.2

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value242425242424242424
Percentage of InterestExpenseIncludingAffiliatedTrusts93.893.993.793.693.693.993.894.094.0

ava:LitigationSettlementIncreasedPotentialClaim us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType

ava:LitigationSettlementIncreasedPotentialClaim

ava:SystemUnitResourceProtectionAct, ava:NaturalAndCulturalDamageClaim, us-gaap:SubsequentEvent


Litigation
Period End2021-07-07
Value6000000.0
Percentage of LitigationSettlementIncreasedPotentialClaim100.0

ava:OtherComprehensiveIncomeLossAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostAdjustmentDueEffectsOfRegulation us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

ava:OtherComprehensiveIncomeLossAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostAdjustmentDueEffectsOfRegulation

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value2.1492.5922.0812.6422.6422.6419.2523.4473.352
Percentage of OtherComprehensiveIncomeLossAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostAdjustmentDueEffectsOfRegulation100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:OtherOperatingExpenses

ava:OtherOperatingExpenses


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value958889878695978194110898688849791898092818481898079828982681141221161121101321071071071129210190988586
Percentage of OtherOperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:OtherOperatingExpenses us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.1591.1841.6281.6970.6591.363.7461.456.332
Percentage of OtherOperatingExpenses1.21.31.81.90.81.43.91.86.7

us-gaap:OperatingSegments, ava:UtilityRevenue


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value948788858694938087
Percentage of OtherOperatingExpenses98.898.798.298.199.298.696.198.293.3

ava:OtherOperatingExpenses us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value3.3252.9563.2243.43.0643.2173.1663.3633.129
Percentage of OtherOperatingExpenses3.53.33.63.93.53.43.34.13.3

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value908485828391907684
Percentage of OtherOperatingExpenses95.395.394.694.295.795.292.994.189.9

ava:OtherRegulatoryAssetsAndLiabilitiesDeferredDebitsAndCredits

ava:OtherRegulatoryAssetsAndLiabilitiesDeferredDebitsAndCredits


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value-2246000.0-1762000.02169000.0-8065000.07511000.0-11902000.01806000.0-749000.0
Percentage of OtherRegulatoryAssetsAndLiabilitiesDeferredDebitsAndCredits100.0100.0100.0100.0100.0100.0100.0100.0

ava:PaymentsForProceedsFromDerivativeInstrumentOperatingActivities us-gaap:DerivativeInstrumentRisk

ava:PaymentsForProceedsFromDerivativeInstrumentOperatingActivities

us-gaap:InterestRateSwap


Payments
Period End2020-07-31
Value33
Percentage of PaymentsForProceedsFromDerivativeInstrumentOperatingActivities100.0

ava:PaymentsToAcquireEquityAndPropertyInvestments

ava:PaymentsToAcquireEquityAndPropertyInvestments


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value3.312.341.9311.8970.7841.3133.4773.407
Percentage of PaymentsToAcquireEquityAndPropertyInvestments100.0100.0100.0100.0100.0100.0100.0100.0

ava:PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure

ava:PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value117971061099495121121106
Percentage of PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:CorporateNonSegment, ava:NonUtilityRevenue


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.5370.028-0.0210.8030.4770.109-0.2690.920.022
Percentage of PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure0.50.0-0.00.70.50.1-0.20.80.0

us-gaap:OperatingSegments, ava:UtilityRevenue


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value116971061089395121120106
Percentage of PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure99.5100.0100.099.399.599.9100.299.2100.0

ava:PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value2.1830.8090.5972.862.0871.471.2152.8363.076
Percentage of PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure1.90.80.62.62.21.51.02.32.9

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value114961051059194120118103
Percentage of PaymentsToAcquirePropertyPlantAndEquipmentExcludesOtherBusinessExpenditure97.799.199.596.697.398.399.296.997.1

ava:PercentageOfNonserviceRelatedNetPeriodicBenefitCostsCapitalizedToRegulatoryAssets

ava:PercentageOfNonserviceRelatedNetPeriodicBenefitCostsCapitalizedToRegulatoryAssets


Percentage
Period End2021-06-302021-03-31
Value040.0
Percentage of PercentageOfNonserviceRelatedNetPeriodicBenefitCostsCapitalizedToRegulatoryAssets0.0100.0

ava:PercentageOfNonserviceRelatedNetPeriodicBenefitCostsRecordedToOtherExpense

ava:PercentageOfNonserviceRelatedNetPeriodicBenefitCostsRecordedToOtherExpense


Percentage
Period End2021-06-302021-03-31
Value060.0
Percentage of PercentageOfNonserviceRelatedNetPeriodicBenefitCostsRecordedToOtherExpense0.0100.0

ava:PercentageOfServiceRelatedNetPeriodicBenefitCostsCapitalizedToUtilityProperty

ava:PercentageOfServiceRelatedNetPeriodicBenefitCostsCapitalizedToUtilityProperty


Percentage
Period End2021-06-302021-03-312020-12-31
Value040.00
Percentage of PercentageOfServiceRelatedNetPeriodicBenefitCostsCapitalizedToUtilityProperty0.0100.00.0

ava:PercentageOfServiceRelatedNetPeriodicBenefitCostsRecordedToOperatingExpenses

ava:PercentageOfServiceRelatedNetPeriodicBenefitCostsRecordedToOperatingExpenses


Percentage
Period End2021-06-302021-03-312020-12-31
Value060.00
Percentage of PercentageOfServiceRelatedNetPeriodicBenefitCostsRecordedToOperatingExpenses0.0100.00.0

ava:PowerAndNaturalGasCostAmortizationDeferralsNet

ava:PowerAndNaturalGasCostAmortizationDeferralsNet


Power
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value-14.015-7.811-3.453-8.285-4.5656.38-0.0821.881
Percentage of PowerAndNaturalGasCostAmortizationDeferralsNet100.0100.0100.0100.0100.0100.0100.0100.0

ava:PublicUtilityOperatingExpensesExciseTaxesCollected

ava:PublicUtilityOperatingExpensesExciseTaxesCollected


Public
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value1319151212181511121914121219161213211412121814121219
Percentage of PublicUtilityOperatingExpensesExciseTaxesCollected100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RegulatedRevenuesExcludingAlternativeRevenuePrograms

ava:RegulatedRevenuesExcludingAlternativeRevenuePrograms


Regulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value301412379276273393364276288393362288309408
Percentage of RegulatedRevenuesExcludingAlternativeRevenuePrograms100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RevenueFromAlternativeRevenuePrograms

ava:RevenueFromAlternativeRevenuePrograms


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value-3.0690.4990.209-3.9724.362-4.413-1.4916.0389.725
Percentage of RevenueFromAlternativeRevenuePrograms100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferences

ava:TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferences


Tax
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-3204000.0-3240000.0-5649000.0-2427000.0-2415000.0-2402000.0-3609000.0-2139000.0-2139000.0-2080000.0-3634000.0-1521000.0-1981000.0-1018000.01238000.0742000.0
Percentage of TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferences100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferencesPercent

ava:TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferencesPercent


Tax
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-19.5-4.00.6-42.3-0.253-0.042-0.006-0.431-0.092-0.014-0.008-0.13-0.064-0.0160.0010.077
Percentage of TaxEffectOfRegulatoryTreatmentOfUtilityPlantDifferencesPercent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:UtilitiesOperatingExpenseDeferralsForProductsAndServices

ava:UtilitiesOperatingExpenseDeferralsForProductsAndServices


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value9013412278671291159888
Percentage of UtilitiesOperatingExpenseDeferralsForProductsAndServices100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:UtilitiesOperatingExpenseDeferralsForProductsAndServices us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:OperatingSegments, ava:UtilityRevenue


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value9013412278671291159888
Percentage of UtilitiesOperatingExpenseDeferralsForProductsAndServices100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:UtilitiesOperatingExpenseDeferralsForProductsAndServices us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AlaskaElectricLightPower


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value1.1630.7390.1370.9420.896-0.01-1.149-0.073-0.067
Percentage of UtilitiesOperatingExpenseDeferralsForProductsAndServices1.30.50.11.21.3-0.0-1.0-0.1-0.1

us-gaap:OperatingSegments, ava:UtilityRevenue, ava:AvistaUtilities


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value8913312277671291169888
Percentage of UtilitiesOperatingExpenseDeferralsForProductsAndServices98.799.599.998.898.7100.0101.0100.1100.1

us-gaap:AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation us-gaap:StatementEquityComponents

us-gaap:AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:CommonStock


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0993000.00002408000.0000891000.00003929000.0132000.0003420000.0-1000.046000.003027000.00352000.001480000.00000
Percentage of AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation0.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0100.00.00.0100.0100.0100.00.0100.00.0100.00.0100.00.00.00.00.0

us-gaap:CommonStockDividendsPerShareCashPaid

us-gaap:CommonStockDividendsPerShareCashPaid


Common
Period End2021-06-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.42250.4050.4050.38750.38750.38750.38750.37250.37250.37250.37250.35750.35750.35750.35750.34250.34250.34250.34250.330.330.330.330.31750.31750.31750.31750.3050.3050.3050.3050.290.290.290.290.2750.2750.2750.2750.250.250.250.25
Percentage of CommonStockDividendsPerShareCashPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-1246000.0-1173000.0-1142000.0-1243000.0-1243000.0-1243000.0-139000.0-1299000.0-1329000.0-1246000.0-971000.0-1044000.0-562000.0-1655000.0-1173000.0-1168000.0-1320000.0-1273000.0-1416000.0-1453000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-1688000.0-1823000.0-1706000.0-1678000.0-1679000.0-1654000.0-2822000.0-2553000.0-2426000.0-2415000.0-2188000.0-1761000.0-1842000.0-2088000.0-2413000.0-2517000.0-2317000.0-2546000.0-2259000.0-2161000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses135.5155.4149.4135.0135.1133.12030.2196.5182.5193.8225.3168.7327.8126.2205.7215.5175.5200.0159.5148.7

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-275000.0-275000.0-133000.0-275000.0-275000.0-275000.0-156000.0-275000.0-275000.0-275000.0-184000.0-299000.0209000.0-815000.0-246000.0-274000.0-312000.0-312000.0-284000.0-300000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value75000.075000.032000.075000.075000.075000.032000.075000.075000.075000.036000.071000.075000.075000.02000.00001000.01000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-27.3-27.3-24.1-27.3-27.3-27.3-20.5-27.3-27.3-27.3-19.6-23.735.9-9.2-0.8-0.0-0.0-0.0-0.4-0.3

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.7830.6750.5670.590.590.630.1560.6160.6110.7180.4230.550.50.50.4740.4750.4750.4750.4460.465
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value9.7049.7758.5118.6258.6259.1258.0827.9137.9537.8158.4178.1018.258.257.9267.97.97.97.0356.887
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets1239.31448.11501.11461.91461.91448.45180.81284.61301.61088.41989.81472.91650.01650.01672.21663.21663.21663.21577.41481.1

us-gaap:DefinedBenefitPlanInterestCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value1.3091.3761.4791.5241.5241.5151.9221.141.1641.3721.1761.2611.1971.1971.3431.3741.3741.3991.4871.53
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value6.536.586.9476.9686.9676.9717.0457.1347.17.1386.536.6346.4666.4666.9956.9766.9766.9516.8496.895
Percentage of DefinedBenefitPlanInterestCost498.9478.2469.7457.2457.2460.1366.5625.8610.0520.3555.3526.1540.2540.2520.8507.7507.7496.9460.6450.7

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value2.3942.6072.8822.8842.8822.8322.4762.3022.362.3972.3052.2712.2722.3412.5942.5922.7062.7092.9893.024
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value4.8434.9495.9215.6455.6465.1216.8026.7976.5966.6875.7335.6835.5835.8296.6646.6856.4856.6396.7216.737
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost202.3189.8205.4195.7195.9180.8274.7295.3279.5279.0248.7250.2245.7249.0256.9257.9239.7245.1224.9222.8

us-gaap:DefinedBenefitPlanServiceCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.8971.0080.9610.9820.980.9790.7270.7540.7530.7720.7650.8150.8040.8040.7980.7990.7990.8240.8160.806
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value6.2546.2465.7475.5495.555.5464.9854.9484.9484.8745.3965.3185.455.455.185.0925.0925.0424.6474.567
Percentage of DefinedBenefitPlanServiceCost697.2619.6598.0565.1566.3566.5685.7656.2657.1631.3705.4652.5677.9677.9649.1637.3637.3611.9569.5566.6

us-gaap:DepreciationAndAmortization

us-gaap:DepreciationAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-03-312012-12-312012-09-30
Value0.0730.1270.1470.1460.1880.2350.1310.1340.1550.2090.2120.2070.1990.1810.2580.1370.1570.1880.1960.1930.1920.1880.1830.1780.1650.1690.1580.1540.1513.7093.963.9093.4934.0643.26
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeNonmonetaryNotionalAmountEnergyMeasure us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:Position, us-gaap:ValuationTechnique

us-gaap:DerivativeNonmonetaryNotionalAmountEnergyMeasure

srt:Maximum, ava:NaturalGasExchangeAgreements, us-gaap:Long, ava:InternallyDerivedWeightedAverageCostOfGas


Derivative
Period End2021-06-302021-03-31
Value0310000.0
Percentage of DerivativeNonmonetaryNotionalAmountEnergyMeasure0.0100.0

srt:Maximum, ava:NaturalGasExchangeAgreements, us-gaap:Short, ava:InternallyDerivedWeightedAverageCostOfGas


Derivative
Period End2021-06-302021-03-312020-12-312020-09-30
Value0310000.000
Percentage of DerivativeNonmonetaryNotionalAmountEnergyMeasure0.0100.00.00.0

srt:Minimum, ava:NaturalGasExchangeAgreements, us-gaap:Long, ava:InternallyDerivedWeightedAverageCostOfGas


Derivative
Period End2021-06-302021-03-31
Value-90000.0130000.0
Percentage of DerivativeNonmonetaryNotionalAmountEnergyMeasure0.041.9

srt:Minimum, ava:NaturalGasExchangeAgreements, us-gaap:Short, ava:InternallyDerivedWeightedAverageCostOfGas


Derivative
Period End2021-06-302021-03-312020-12-312020-09-30
Value075000.0-65000.0126000.0
Percentage of DerivativeNonmonetaryNotionalAmountEnergyMeasure0.024.20.00.0

us-gaap:DividendsCommonStockCash us-gaap:StatementEquityComponents

us-gaap:DividendsCommonStockCash

us-gaap:RetainedEarnings


Dividends
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value3029192-27.573-27.3192726252525242424242323232321212121202020201920191918181818171717171615151514131313
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate


Effective
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-012017-12-312017-09-302017-06-302017-03-31
Value21.021.0021.00.210.2100.210.210.2100.210.210.210.2100.3500.35
Percentage of EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.00.0100.00.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments


Effective
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value11.5-3.60.433.50.127-0.042-0.0150.4840.0220.0070.0040.070.019-0.0320.007-0.068
Percentage of EffectiveIncomeTaxRateReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes

us-gaap:EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes


Effective
Period End2020-09-302019-12-312019-09-30
Value9.1-1.097-12.2
Percentage of EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes

us-gaap:EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes


Effective
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value1.70.7-0.1-6.3-0.0340.0210.001-0.16100.0110.001-0.0270.0020.015-0.002-0.031
Percentage of EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements

us-gaap:FairValueInputsLevel3


Fair
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value-1377000.0016000.0238000.0-1000.0-9000.0-901000.0-5413000.0-635000.001314000.05115000.02625000.0-43000.01607000.03118000.0150000.001879000.04978000.03149000.0282000.01257000.03852000.02036000.00676000.0-4257000.0-214000.0-1000.0468000.01843000.02223000.0-1000.01014000.01296000.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass

us-gaap:FairValueInputsLevel3, ava:NaturalGasExchangeAgreements


Fair
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-30
Value-145000.0-1011000.0-1377000.0016000.0238000.0-2000.0-9000.0-59000.0-8307000.0-185000.0093000.0156000.0-43000.0300000.0-405000.00700000.0778000.0282000.0521000.075000.000
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements0.00.0100.00.0100.0100.0200.0100.06.5153.529.10.07.13.0100.018.7-13.00.037.315.6100.041.41.90.00.0

us-gaap:GainLossOnSaleOfInvestments

us-gaap:GainLossOnSaleOfInvestments


Gain
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-03-31
Value1609000.0155000.0683000.0-11000.03242000.00
Percentage of GainLossOnSaleOfInvestments100.0100.0100.0100.0100.00.0

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
Value3.45916131.2042.00211111.0414.87430112.4526.47913203.364
Percentage of IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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
Value1884000.0-2916000.0366000.01921000.01209000.0-2419000.0-2732000.02404000.0525000.01011000.0345000.0814000.0589000.0-2082000.0569000.0-649000.0
Percentage of IncomeTaxReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationPriorYearIncomeTaxes

us-gaap:IncomeTaxReconciliationPriorYearIncomeTaxes


Income
Period End2020-09-302019-12-312019-09-30
Value524000.0-1352000.0-604000.0
Percentage of IncomeTaxReconciliationPriorYearIncomeTaxes100.0100.0100.0

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes

us-gaap:IncomeTaxReconciliationStateAndLocalIncomeTaxes


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value280000.0552000.0275000.0-363000.0-325000.01227000.0614000.0-800000.0-8000.01659000.0497000.0-319000.060000.0964000.0-26000.0-301000.0
Percentage of IncomeTaxReconciliationStateAndLocalIncomeTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable

us-gaap:IncreaseDecreaseInAccountsAndNotesReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-19.556-6.72856-1.851-37.623-6.07858-6.783-57.5589.78760-10.035-49.88-15.96361-7.159-46.0430.66836-3.664-31.698-18.36438-24.064-22.796-2.66448-5.675-41.829-17.25783-7.238-41.011-2.43253-5.387-39.64-16.07945-10.549-53.231-12.50570-5.714-34.886-10.344
Percentage of IncreaseDecreaseInAccountsAndNotesReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccruedIncomeTaxesPayable

us-gaap:IncreaseDecreaseInAccruedIncomeTaxesPayable


Increase
Period End2021-03-312020-03-312019-03-312018-03-312017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-30
Value0.5574.90119150.0-0.147-0.2071.067-0.897-19.10720-90.7327819-9.984
Percentage of IncreaseDecreaseInAccruedIncomeTaxesPayable100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredIncomeTaxes us-gaap:SubsequentEventType

us-gaap:IncreaseDecreaseInDeferredIncomeTaxes

us-gaap:SubsequentEvent


Increase
Period End2020-10-31
Value62
Percentage of IncreaseDecreaseInDeferredIncomeTaxes100.0

us-gaap:IncreaseDecreaseInDepositOtherAssets

us-gaap:IncreaseDecreaseInDepositOtherAssets


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value25-1.4978.526-17.314-7.074140.796-17.418-43.92-3.43251-3.07-25.698-18.38220-3.5642.842.62-9.042-63.7454042-3.384-9.009-19.42418-29.279-3.775
Percentage of IncreaseDecreaseInDepositOtherAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-18.427-5.442445.5571.394-10.5-0.389.633-0.5170.0-8.0155.9180.39-0.314-57.668161.649-14.106-59.1452312-11.2163-0.3150.38-43.331358.4280.0-7.783
Percentage of IncreaseDecreaseInIncomeTaxesReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingAssets

us-gaap:IncreaseDecreaseInOtherOperatingAssets


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-2.7650.268.753-12.0563.5382.166-7.7662.6410-1.7054.7121.785-4.6950.7872.09-3.8093.7090.116-12.3934.05-6.54210-1.070.7992.1380.471108.81618-30.333-4.69411-2.92314-20.0498.4855.571-21.265-4.286308.362-10.509223.773-4.92-12.599
Percentage of IncreaseDecreaseInOtherOperatingAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-14.76216-0.07412-18.89421-5.99510-35.71730-10.00911-39.93438-7.56612-20.56516-6.89215-13.36415-11.7119.41-14.444104.85713-12.79326-2.4422.072-31.50140-11.75112-19.28612-10.16513-10.1417.118-0.16220-15.3422.193
Percentage of IncreaseDecreaseInOtherOperatingLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements


Incremental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value130000.0213000.09000.0143000.0108000.0142000.038000.086000.069000.0208000.0-39000.0338000.0306000.0292000.064000.0480000.0152000.0107000.07000.0468000.0397000.0302000.015000.0389000.0319000.0571000.043000.0310000.0279000.046000.06000.038000.025000.032000.0-72000.071000.0211000.0344000.023000.0131000.0306000.012000.0
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestExpenseRelatedParty

us-gaap:InterestExpenseRelatedParty


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value106000.0109000.0107000.0128000.0208000.0270000.0300000.0334000.0351000.0
Percentage of InterestExpenseRelatedParty100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LitigationSettlementAmountAwardedToOtherParty us-gaap:LossContingenciesByNatureOfContingency, us-gaap:SubsequentEventType

us-gaap:LitigationSettlementAmountAwardedToOtherParty

ava:NaturalAndCulturalDamageClaim, us-gaap:SubsequentEvent


Litigation
Period End2021-07-07
Value2000000.0
Percentage of LitigationSettlementAmountAwardedToOtherParty100.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-200000.0-200000.0-194000.0-200000.0-200000.0200000.0194000.0200000.0200000.0200000.0220000.0228000.0228000.0228000.03483000.0300000.0-299000.0-299000.0-237000.0-312000.0-311000.0-311000.0-850000.0273000.0273000.0273000.06949000.0-1951000.0-1952000.0-1952000.03992000.0-4891000.0-4891000.0-4891000.0
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value-308000.0-315000.04764000.0-220000.0-220000.0-205000.02876000.0-162000.0-161000.0-160000.0-1354000.0-204000.0-204000.0-204000.01070000.0-182000.0-183000.0-183000.0-31000.0-140000.0-140000.01229000.0-501000.0-246000.0-245000.0-246000.03990000.0-112000.0-112000.0-111000.0-2083000.0-184000.0-183000.0-184000.01585000.0-168000.0-168000.0-153000.01432000.0-123000.0-60000.0
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value82000.084000.0-1266000.058000.059000.0-54000.0-508000.0-43000.0-42000.0-43000.0686000.0-54000.0-54000.0-55000.014000.0-98000.099000.098000.017000.075000.076000.0-663000.0271000.0132000.0132000.0132000.0-2148000.060000.062000.059000.01121000.099000.099000.099000.0-853000.090000.091000.082000.0-771000.066000.033000.0
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value390000.0399000.0-6030000.0278000.0279000.0-259000.03640000.0-205000.0-203000.0-203000.0-1714000.0-258000.0-258000.0-259000.01646000.0-280000.0-282000.0-281000.0-48000.0-215000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-2.739-3.1913.755-3.12-3.1213.15.8063.8523.7553.661-24.5062.9622.9952.995253.637-3.638-3.63818-3.642-3.642-3.642-13.6863.6883.6873.688-89.2691.9881.991.99
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value308000.0315000.0-4764000.0220000.0220000.0-205000.02876000.0-162000.0-161000.0-160000.0-1354000.0-204000.0-204000.0-204000.01070000.0-182000.0-183000.0-183000.0-31000.0-140000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value82000.084000.0-1266000.058000.059000.0-54000.0764000.0-43000.0-42000.0-43000.0-360000.0-54000.0-54000.0-55000.0576000.0-98000.0-99000.0-98000.0-17000.0-75000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherCostAndExpenseOperating


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.1591.1841.6281.6970.6591.363.7461.456.3327.3557.3677.3476.5436.8245.7876.5987.0866.1796.6396.7566.2815.8256.6026.4626.6469.8169.904100.889.3839.679109.4159.345-92.2864243434631323118252825
Percentage of OtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:OtherOperatingActivitiesCashFlowStatement


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value-4.825-2.828-10.8093.7643.9315.112-8.431-1.191-1.961-1.943-2.8481.854-1.673.7782.05-0.610.536-0.11620-7.0264.61-12.747-6.1644.499-2.139-3.077-5.5595.794.5664.2126.0932.9962.7751.118-47.603191914-37.946119.10312
Percentage of OtherOperatingActivitiesCashFlowStatement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsForProceedsFromOtherInvestingActivities


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.449-2.3561.4270.490.3260.662-1.0940.763-1.8270.7550.4852.296-1.3040.8663.5851.7710.8410.102-19.3332.967202.6579.902-0.6921.689-0.8911.4530.7190.499-0.024-5.1422.1122.721.6490.0633.2541.532.6281.8311.0432.0591.5022.8150.502-0.9391.733
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireNotesReceivable

us-gaap:PaymentsToAcquireNotesReceivable


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0.00.0750.050.01.5642.7791.2675.1360.70.20.6250.151.781.00.90.32.10.40.3760.058.5921.076
Percentage of PaymentsToAcquireNotesReceivable0.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementBenefitExpense

us-gaap:PensionAndOtherPostretirementBenefitExpense


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value7.2377.5568.8028.5298.5297.9529.2789.0998.9569.0848.0377.9557.8558.179.2589.2779.1919.3489.719.7619.849.4758.8719.3939.5699.2175.5625.7964.177.415101010101010109.727
Percentage of PensionAndOtherPostretirementBenefitExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionContributions

us-gaap:PensionContributions


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value14140.07.47.37.30.07.47.37.30.07.47.37.30.07.27.47.40.04.04.04.00.04.04.04.00.01010110.2630.01414140.08.758.758.50.07.07.07.0
Percentage of PensionContributions100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromIssuanceOfCommonStock


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value150.0651829230.1752127140.19-0.017-0.0030.9950.232540.2430.9320.3150.1971920270.1630.3170.7090.3710.6351.4451.3420.6380.131.4621.8681.1490.38252.1381.4375.2475.3387.428.45811259.1360.374
Percentage of ProceedsFromIssuanceOfCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-1813000.0-1085000.0-489000.0-241000.0-2171000.0-2406000.0-892000.0-1000.0-613000.0-896000.0268000.0354000.0-4055000.0-4483000.0-405000.0-313000.0-3000.0-3442000.0-636000.0-162000.0-2189000.0-1423000.0-364000.0-218000.0-142000.0-1329000.0-395000.0-698000.03023000.0064000.0140000.09000.0110000.0-65000.0113000.0663000.0350000.02000.0513000.02000.013000.0-43000.038000.00-113000.0
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:ProceedsFromSaleOfEquityMethodInvestments

us-gaap:ProceedsFromSaleOfEquityMethodInvestments


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-03-31
Value6.0050.8010.1421.5-0.0045.1480.0
Percentage of ProceedsFromSaleOfEquityMethodInvestments100.0100.0100.0100.0100.0100.00.0

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions


Public
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value916000.01015000.01104000.01009000.0972000.0998000.01056000.01089000.01101000.0928000.0615000.01217000.01139000.0968000.0797000.0899000.0890000.0724000.0393000.0507000.0837000.0914000.0845000.0905000.0879000.0917000.01217000.01212000.0834000.0
Percentage of PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity


Public
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1592000.01754000.01940000.01759000.01672000.01599000.01564000.01768000.01768000.01485000.02148000.01561000.01453000.01392000.01657000.01720000.01642000.01650000.02169000.01938000.02107000.02261000.02440000.02017000.01659000.02215000.02382000.02189000.02203000.02034000.01725000.01595000.01355000.01391000.01180000.01127000.0905000.0843000.0570000.0421000.0392000.0842000.01917000.0552000.0474000.0410000.0
Percentage of PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfDebt us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:StatementBusinessSegments

us-gaap:RepaymentsOfDebt

ava:TwoThousandNineteen, us-gaap:FirstMortgage, ava:AvistaUtilities


Repayments
Period End2020-09-302019-11-30
Value5290
Percentage of RepaymentsOfDebt100.0100.0

us-gaap:UtilitiesOperatingExpenseDepreciationAndAmortization

us-gaap:UtilitiesOperatingExpenseDepreciationAndAmortization


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value56555453635150505548464645444342424141403939373635343433313030292927282827272726262526242424
Percentage of UtilitiesOperatingExpenseDepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value948788858694938087838178817784778174867578758274737379726767756965658564636366606859
Percentage of UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UtilitiesOperatingExpenseProductsAndServices

us-gaap:UtilitiesOperatingExpenseProductsAndServices


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value9013412278671291159888137132101105154147108102165161118109161168138141209197131128220202131126229192153135211214171155248166201168259
Percentage of UtilitiesOperatingExpenseProductsAndServices100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UtilitiesOperatingExpenseTaxes

us-gaap:UtilitiesOperatingExpenseTaxes


Utilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value24322624243027232231252525302723233224222229222223292321212822182125191820252116192418151721
Percentage of UtilitiesOperatingExpenseTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:AccumulatedComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansRegulatoryAssetInNetPeriodicBenefitCostNetOfTax us-gaap:RetirementPlanType

ava:AccumulatedComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansRegulatoryAssetInNetPeriodicBenefitCostNetOfTax

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4857463847
Percentage of AccumulatedComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansRegulatoryAssetInNetPeriodicBenefitCostNetOfTax100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value10810713397108
Percentage of AccumulatedComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansRegulatoryAssetInNetPeriodicBenefitCostNetOfTax222.3186.7283.9249.4230.7

ava:AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeRegulatoryAssetNetOfTax us-gaap:RetirementPlanType

ava:AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeRegulatoryAssetNetOfTax

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-31
Value5058
Percentage of AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeRegulatoryAssetNetOfTax100.0100.0

us-gaap:PensionPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-31
Value121116
Percentage of AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBeforeRegulatoryAssetNetOfTax241.6198.4

ava:AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossTax

ava:AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value3656000.03738000.03822000.02556000.02614000.02673000.02727000.01963000.02006000.02048000.02091000.02451000.02505000.02559000.04356000.03780000.03878000.03977000.04075000.04092000.04167000.04243000.03580000.0-3852000.0-4360000.0-4115000.0-4247000.0-2099000.0-2159000.0-2220000.0-2280000.0-3401000.0-3500000.0-3599000.0-3698000.0-3107000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:AmountAvailableForDividendDistributionWithoutAffectingCovenants

ava:AmountAvailableForDividendDistributionWithoutAffectingCovenants


Amount
Period End2020-12-31
Value311
Percentage of AmountAvailableForDividendDistributionWithoutAffectingCovenants100.0

ava:AmountOfFirstMortgageBondsThatCouldBeIssued us-gaap:LongtermDebtType, us-gaap:StatementBusinessSegments

ava:AmountOfFirstMortgageBondsThatCouldBeIssued

us-gaap:FirstMortgage, ava:AlaskaElectricLightPower


Amount
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value36300.00.00.00.0
Percentage of AmountOfFirstMortgageBondsThatCouldBeIssued100.0100.00.00.00.00.0

us-gaap:FirstMortgage, ava:AvistaUtilities


Amount
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value170015001200130012001100
Percentage of AmountOfFirstMortgageBondsThatCouldBeIssued4709.14934.20.00.00.00.0

ava:AssetsHeldForSale

ava:AssetsHeldForSale


Assets
Period End2021-03-312020-12-31
Value3363000.03462000.0
Percentage of AssetsHeldForSale100.0100.0

ava:CommonStockIssuedRangePercentOfPerformanceSharesGranted us-gaap:Range, us-gaap:AwardType

ava:CommonStockIssuedRangePercentOfPerformanceSharesGranted

srt:Maximum, ava:TotalShareholderReturnMarketBasedAwardsAndPerformanceAwards


Common
Period End2020-12-31
Value200.0
Percentage of CommonStockIssuedRangePercentOfPerformanceSharesGranted100.0

srt:Minimum, ava:TotalShareholderReturnMarketBasedAwardsAndPerformanceAwards


Common
Period End2020-12-31
Value0
Percentage of CommonStockIssuedRangePercentOfPerformanceSharesGranted0.0

ava:CommonStockSharesAuthorizedUnderSalesAgencyAgreementsRemainingSharesAuthorizedToSell us-gaap:SubsidiarySaleOfStock

ava:CommonStockSharesAuthorizedUnderSalesAgencyAgreementsRemainingSharesAuthorizedToSell

ava:SalesAgencyAgreement


Common
Period End2021-03-312020-12-312020-09-30
Value1300000.01300000.01800000.0
Percentage of CommonStockSharesAuthorizedUnderSalesAgencyAgreementsRemainingSharesAuthorizedToSell100.0100.0100.0

ava:DeferredCompensationAssetsAndLiabilities us-gaap:DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensation

ava:DeferredCompensationAssetsAndLiabilities

us-gaap:DeferredCompensationExcludingShareBasedPaymentsAndRetirementBenefits


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value9174000.08948000.08400000.08458000.07679000.08093000.08677000.09170000.0
Percentage of DeferredCompensationAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.0100.0

ava:DeferredNetBenefitToCustomers us-gaap:UnusualOrInfrequentItem

ava:DeferredNetBenefitToCustomers

ava:COVID19


Deferred
Period End2020-12-31
Value2800000.0
Percentage of DeferredNetBenefitToCustomers100.0

ava:DeferredTaxAssetsRegulatoryLiabilities

ava:DeferredTaxAssetsRegulatoryLiabilities


Deferred
Period End2020-12-312019-12-31
Value179181
Percentage of DeferredTaxAssetsRegulatoryLiabilities100.0100.0

ava:LineofCreditFacilityCovenantTermsMaximumDebttoEquityRatio us-gaap:StatementBusinessSegments

ava:LineofCreditFacilityCovenantTermsMaximumDebttoEquityRatio

ava:AlaskaElectricLightPower


Lineof
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value67.50.6750.6750.6750.6750.68
Percentage of LineofCreditFacilityCovenantTermsMaximumDebttoEquityRatio100.0100.0100.0100.0100.0100.0

ava:AvistaUtilities


Lineof
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value65.00.650.650.650.650.65
Percentage of LineofCreditFacilityCovenantTermsMaximumDebttoEquityRatio96.396.396.396.396.395.6

ava:LongTermDebtBeforeCurrentPortionAndBondsHeldByCompany

ava:LongTermDebtBeforeCurrentPortionAndBondsHeldByCompany


Long
Period End2020-12-312019-12-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302016-12-312016-09-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value2092197919461947194718521853176417651765165616561568158115821582150213561356135614061315131213121232123112611261117511861185
Percentage of LongTermDebtBeforeCurrentPortionAndBondsHeldByCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:NonRegulatedProperty

ava:NonRegulatedProperty


Non
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value181819222627
Percentage of NonRegulatedProperty100.0100.0100.0100.0100.0100.0

ava:NumberOfResidentialCommercialAndOtherStructuresImpacted us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency

ava:NumberOfResidentialCommercialAndOtherStructuresImpacted

ava:LaborDayWindstorm, us-gaap:DamageFromFireExplosionOrOtherHazard


Number
Period End2020-09-02
Value230.0
Percentage of NumberOfResidentialCommercialAndOtherStructuresImpacted100.0

ava:NumberOfShareRequestedToRegulatoryAuthority us-gaap:SubsidiarySaleOfStock

ava:NumberOfShareRequestedToRegulatoryAuthority

ava:SalesAgencyAgreement


Number
Period End2021-03-31
Value3000000.0
Percentage of NumberOfShareRequestedToRegulatoryAuthority100.0

ava:NumberOfSharesAuthorizedToIssueByRegulatoryAuthority us-gaap:StatementEquityComponents

ava:NumberOfSharesAuthorizedToIssueByRegulatoryAuthority

us-gaap:CommonStock


Number
Period End2021-06-30
Value3900000.0
Percentage of NumberOfSharesAuthorizedToIssueByRegulatoryAuthority100.0

ava:PendingRegulatoryTreatmentLiability

ava:PendingRegulatoryTreatmentLiability


Pending
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value104.26720453153.4233425
Percentage of PendingRegulatoryTreatmentLiability100.0100.0100.0100.0100.0100.0100.0100.0

ava:PendingRegulatoryTreatmentLiability us-gaap:RegulatoryLiability

ava:COVID19Deferrals


Pending
Period End2020-12-31
Value10
Percentage of PendingRegulatoryTreatmentLiability100.0

ava:PropertyPlantAndEquipmentTotal

ava:PropertyPlantAndEquipmentTotal


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value70016656640960475687535749714502425040143840
Percentage of PropertyPlantAndEquipmentTotal100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RegulatoryAssetEarningReturn

ava:RegulatoryAssetEarningReturn


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value448408298258270190191168180109
Percentage of RegulatoryAssetEarningReturn100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RegulatoryAssetEarningReturn us-gaap:RegulatoryAsset

ava:AFUDCAboveFERCAllowedRate


Regulatory
Period End2020-12-312019-12-31
Value4740
Percentage of RegulatoryAssetEarningReturn10.610.0

ava:Decoupling


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value242620224313
Percentage of RegulatoryAssetEarningReturn5.46.67.08.615.97.0

ava:PowerDeferralsRegulatoryAssets


Regulatory
Period End2020-12-31
Value3.337
Percentage of RegulatoryAssetEarningReturn0.7

ava:RegulatoryAssetSettlement


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value40414243454647495052
Percentage of RegulatoryAssetEarningReturn8.910.114.317.016.724.425.029.227.947.8

ava:UnamortizedDebtRepurchaseCosts


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value7.5128.8841011131517192123
Percentage of RegulatoryAssetEarningReturn1.72.23.44.65.18.19.111.512.021.0

us-gaap:AdvancedMeteringInfrastructureCosts


Regulatory
Period End2020-12-31
Value26
Percentage of RegulatoryAssetEarningReturn5.9

us-gaap:AssetImpairmentForRegulatoryAction


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2831242419
Percentage of RegulatoryAssetEarningReturn6.47.78.29.47.1

us-gaap:DeferredDerivativeGainLoss


Regulatory
Period End2020-12-312017-12-312016-12-31
Value1305337
Percentage of RegulatoryAssetEarningReturn29.120.814.0

us-gaap:DeferredIncomeTaxCharges


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value10895919010110110071
Percentage of RegulatoryAssetEarningReturn24.223.530.634.937.553.152.442.4

us-gaap:OtherRegulatoryAssetsLiabilities


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value3141148.2123.6333.1322.8794.002
Percentage of RegulatoryAssetEarningReturn7.110.14.93.21.31.61.52.4

ava:RegulatoryLiabilityEarningReturn

ava:RegulatoryLiabilityEarningReturn


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value785802853372345302278280271256
Percentage of RegulatoryLiabilityEarningReturn100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RegulatoryLiabilityEarningReturn us-gaap:RegulatoryLiability

ava:Decoupling


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value2.9662.6536.9865.8162.4052.373
Percentage of RegulatoryLiabilityEarningReturn0.40.30.81.60.70.8

ava:NaturalGasDeferrals


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value0.8743.189403730173.921126.91712
Percentage of RegulatoryLiabilityEarningReturn0.10.44.810.18.95.91.44.32.64.7

ava:PowerDeferralsRegulatoryLiability


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value3737422923181417
Percentage of RegulatoryLiabilityEarningReturn4.84.74.98.06.86.25.16.4

us-gaap:DeferredDerivativeGainLoss


Regulatory
Period End2020-12-312017-12-312016-12-31
Value151112
Percentage of RegulatoryLiabilityEarningReturn1.93.03.6

us-gaap:DeferredIncomeTaxCharges


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3904164360.00.0
Percentage of RegulatoryLiabilityEarningReturn49.751.951.20.00.0

us-gaap:OtherRegulatoryAssetsLiabilities


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1213171.9262.5052.3955.9197.249
Percentage of RegulatoryLiabilityEarningReturn1.61.72.00.50.70.82.12.6

us-gaap:RemovalCosts


Regulatory
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value325312297285273261254242
Percentage of RegulatoryLiabilityEarningReturn41.538.934.976.879.386.391.486.7

ava:RegulatoryRestrictionsMaximumDebttoEquity us-gaap:StatementBusinessSegments

ava:RegulatoryRestrictionsMaximumDebttoEquity

ava:AvistaUtilities


Regulatory
Period End2020-12-31
Value35.0
Percentage of RegulatoryRestrictionsMaximumDebttoEquity100.0

ava:RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided

ava:RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided


Remaining
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value35202023352720492621
Percentage of RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided us-gaap:RegulatoryLiability

us-gaap:DeferredIncomeTaxCharges


Remaining
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2414161828
Percentage of RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided69.871.282.078.980.6

us-gaap:OtherRegulatoryAssetsLiabilities


Remaining
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value105.943.7042.5283.2571.0481.3096.411
Percentage of RemainingAmountsOfRegulatoryLiabilitiesForWhichNoInterestDuringRecoveryPeriodIsProvided30.228.818.010.99.13.86.413.0

ava:RoadFireCoveredArea us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency

ava:RoadFireCoveredArea

ava:BabbRoadFire, us-gaap:DamageFromFireExplosionOrOtherHazard


Road
Period End2021-05-14
Value15000.0
Percentage of RoadFireCoveredArea100.0

ava:SecuredandUnsecuredDebt

ava:SecuredandUnsecuredDebt


Securedand
Period End2020-12-312019-12-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302016-12-312015-12-312015-03-312014-12-312013-12-31
Value2107199419041904190418011711171117111626152615261376
Percentage of SecuredandUnsecuredDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ava:TaxCreditCarryforwardsNetofValuationAllowance us-gaap:TaxCreditCarryforward

ava:TaxCreditCarryforwardsNetofValuationAllowance

ava:StateTaxCreditCarryforward


Tax
Period End2020-12-312019-12-31
Value8600000.06000000.0
Percentage of TaxCreditCarryforwardsNetofValuationAllowance100.0100.0

ava:VariableInterestEntityRemainingInvestmentCommitmentAmount us-gaap:CounterpartyName

ava:VariableInterestEntityRemainingInvestmentCommitmentAmount

ava:LimitedPartnershipsAndSimilarEntities


Variable
Period End2020-12-31
Value30
Percentage of VariableInterestEntityRemainingInvestmentCommitmentAmount100.0

ava:WildfireCoveredArea us-gaap:LitigationCase, us-gaap:LossContingenciesByNatureOfContingency

ava:WildfireCoveredArea

ava:LaborDayWindstorm, us-gaap:DamageFromFireExplosionOrOtherHazard


Wildfire
Period End2020-09-02
Value22000.0
Percentage of WildfireCoveredArea100.0

us-gaap:AccountsNotesAndLoansReceivableNetCurrent

us-gaap:AccountsNotesAndLoansReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value129153163108115155166108115170165104117168185125133179180116121149169110136162171124127202221139147190193141148188203155165218230210
Percentage of AccountsNotesAndLoansReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent


Accrual
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value4256454138483635354936373445333433423330
Percentage of AccrualForTaxesOtherThanIncomeTaxesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedVacationCurrent

us-gaap:AccruedVacationCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value2828262525242221222120202020
Percentage of AccruedVacationCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedDeferredInvestmentTaxCredit

us-gaap:AccumulatedDeferredInvestmentTaxCredit


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value292929303030303031312930
Percentage of AccumulatedDeferredInvestmentTaxCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value-13.755-14.063-14.378-9.614-9.834-10.054-10.259-7.383-7.545-7.706-7.866-9.22-9.424-9.628-8.09-7.02-7.202-7.385-7.568-7.599-7.739-7.879-6.657.1517.3977.6427.8883.8984.014.1224.2336.3166.56.6846.867-5.771-4.326
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1.4591.1810.2790.4250.247
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax-10.1-11.5-3.5-5.3-3.3

us-gaap:PensionPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value129.0787.5877.6657.321
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax-89.9-88.5-96.5-94.7-96.7

us-gaap:AdditionalCollateralAggregateFairValue us-gaap:DerivativeInstrumentRisk

us-gaap:AdditionalCollateralAggregateFairValue

us-gaap:CommodityContract


Additional
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value0.0030.0250.0010.8141.3391.5631.4152.1931.4251.5291.3761.3360.670.6480.7711.0461.9661.0881.4166.988.43316
Percentage of AdditionalCollateralAggregateFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestRateSwap


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value321142566781264425106.5794.4472.48.61812111321321818
Percentage of AdditionalCollateralAggregateFairValue0.00.00.01883266.7268152.08128000.03306.13315.21662.6711.2300.0312.1157.0625.01404.91900.01729.91726.32017.21639.41702.2268.6

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value111211116.0344.5762.4192.5293.4156.3955.2335.7056.0776.0775.1324.8385.6075.9665.0264.2664.5075.1214.535.1218.0946.4814.8884.3314.62644444444444444444543434444444245
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmountOfRegulatoryCostsNotYetApproved

us-gaap:AmountOfRegulatoryCostsNotYetApproved


Amount
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-06-302014-03-312013-12-312013-09-302012-12-312011-12-31
Value9549521201284.9244.4961.31.34.5971.3311265
Percentage of AmountOfRegulatoryCostsNotYetApproved100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmountOfRegulatoryCostsNotYetApproved us-gaap:RegulatoryAsset

ava:COVID19Deferrals


Amount
Period End2020-12-31
Value8.166
Percentage of AmountOfRegulatoryCostsNotYetApproved8.6

us-gaap:DeferredDerivativeGainLoss


Amount
Period End2020-12-312017-12-312016-12-31
Value84115123
Percentage of AmountOfRegulatoryCostsNotYetApproved88.496.296.4

us-gaap:OtherRegulatoryAssetsLiabilities


Amount
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2.9352.926124.5554.5854.9244.4964.597
Percentage of AmountOfRegulatoryCostsNotYetApproved3.15.924.03.83.6100.0100.0100.0

us-gaap:AssetRetirementObligation

us-gaap:AssetRetirementObligation


Asset
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-312015-12-312015-09-302015-06-302014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value161717192020201818181817151514143.0282.8593.1683.5133.8873.9714.208
Percentage of AssetRetirementObligation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:AssetsFairValueDisclosure

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value9.5489.2698.6998.3228.0238.2278.5038.4098.1128.2147.9028.269
Percentage of AssetsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value442824353435433532364651
Percentage of AssetsFairValueDisclosure467.8306.7283.1428.6435.0426.6508.0422.8400.8444.0592.5620.7

us-gaap:FairValueInputsLevel3, us-gaap:FairValueMeasurementsRecurring


Assets
Period End2021-06-302021-03-312020-12-312020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value0.1190.0950.0750.0260.0270.0430.0450.1230.0310.183
Percentage of AssetsFairValueDisclosure1.21.00.90.30.30.50.61.50.42.2

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value171310128.96712109.298.913111814
Percentage of AssetsFairValueDisclosure180.8151.0117.5144.9111.8151.2120.9110.5109.9137.2231.6175.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-312017-12-31
Value39211484116189.89614171416
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CollateralAlreadyPostedAggregateFairValue us-gaap:DerivativeInstrumentRisk

us-gaap:CollateralAlreadyPostedAggregateFairValue

us-gaap:CommodityContract


Collateral
Period End2021-06-302021-03-312020-12-312020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value317.5964.9531.7757.8124.9062672782729283919151817182929282327172026
Percentage of CollateralAlreadyPostedAggregateFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestRateSwap


Collateral
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value5.853.918.051010276.778.885.032.860.530.00.5927343441363464117763436225010127.02.2
Percentage of CollateralAlreadyPostedAggregateFairValue18.751.5162.50.00.01526.286.7181.019.24.00.70.02.097.288.6175.6261.1195.2203.7354.8400.1256.6118.5157.180.1289.052.90.00.00.0

us-gaap:DebtInstrumentFaceAmount us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument

us-gaap:DebtInstrumentFaceAmount

srt:Subsidiaries, ava:NineteenNinetySevenFloatingRateJuniorSubordinatedDeferrableInterestDebenturesSeriesB


Debt
Period End2021-06-30
Value51
Percentage of DebtInstrumentFaceAmount100.0

us-gaap:DebtInstrumentFaceAmount us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, us-gaap:ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTerms

srt:Subsidiaries, ava:NineteenNinetySevenFloatingRateJuniorSubordinatedDeferrableInterestDebenturesSeriesB, us-gaap:CommonStockSubjectToMandatoryRedemption


Debt
Period End2021-06-30
Value1.5
Percentage of DebtInstrumentFaceAmount2.9

srt:Subsidiaries, ava:NineteenNinetySevenFloatingRateJuniorSubordinatedDeferrableInterestDebenturesSeriesB, us-gaap:TrustPreferredSecuritiesSubjectToMandatoryRedemption


Debt
Period End2021-06-30
Value50
Percentage of DebtInstrumentFaceAmount97.1

us-gaap:DebtInstrumentUnamortizedDiscount

us-gaap:DebtInstrumentUnamortizedDiscount


Debt
Period End2020-12-312019-12-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302016-12-312016-09-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312011-09-302011-06-302010-12-31
Value710000.0788000.0882000.0905000.0922000.0626000.0668000.0709000.0792000.0833000.0916000.0956000.0998000.01039000.01081000.01122000.0954000.01205000.01246000.01287000.01330000.01370000.01411000.01453000.01626000.01667000.01708000.01792000.0
Percentage of DebtInstrumentUnamortizedDiscount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredCompensationPlanAssets

us-gaap:DeferredCompensationPlanAssets


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value9660000.09469000.09174000.09030000.08435000.08670000.08948000.08852000.08557000.08675000.08400000.08458000.0
Percentage of DeferredCompensationPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredCompensationShareBasedArrangementsLiabilityCurrent us-gaap:AwardType

us-gaap:DeferredCompensationShareBasedArrangementsLiabilityCurrent

ava:TotalShareholderReturnMarketBasedAwardsAndPerformanceAwards


Deferred
Period End2020-12-312019-12-31
Value800000.0900000.0
Percentage of DeferredCompensationShareBasedArrangementsLiabilityCurrent100.0100.0

us-gaap:DeferredGasCost

us-gaap:DeferredGasCost


Deferred
Period End2020-12-31
Value1400000.0
Percentage of DeferredGasCost100.0

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredIncomeTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value9027267056931048935826647691677
Percentage of DeferredIncomeTaxLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsGross


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value317214231237215190169
Percentage of DeferredTaxAssetsGross100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value4217161529291.77629191823
Percentage of DeferredTaxAssetsOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwards

us-gaap:DeferredTaxAssetsTaxCreditCarryforwards


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value5721212327151611191614
Percentage of DeferredTaxAssetsTaxCreditCarryforwards100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value3743454180757242948054
Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value2.8848.7346.7515.8068.2987.3991614181413
Percentage of DeferredTaxLiabilitiesOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value666525509494812723690521494478457
Percentage of DeferredTaxLiabilitiesPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesRegulatoryAssets

us-gaap:DeferredTaxLiabilitiesRegulatoryAssets


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value232201516301182541079162
Percentage of DeferredTaxLiabilitiesRegulatoryAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-53737000.0-63101000.0-52441000.0-44382000.0-53303000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-119320000.0-114370000.0-138520000.0-102620000.0-116210000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax222.0181.2264.1231.2218.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-3570000.0-4400000.0-5230000.0-5058000.0-5854000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1902000.02105000.02308000.02066000.015000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax-53.3-47.8-44.1-40.8-0.3

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3.270.03890.04320.03720.0423
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3.250.03850.04310.03710.0426
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate99.499.099.899.7100.7

us-gaap:DefinedBenefitPlanBenefitObligation ava:DefinedBenefitPlanBenefitObligationbyParticipantType, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanBenefitObligation

ava:Fullyeligibleemployees, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3234293234
Percentage of DefinedBenefitPlanBenefitObligation100.0100.0100.0100.0100.0

ava:Otherparticipants, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value5351403941
Percentage of DefinedBenefitPlanBenefitObligation165.9150.3135.0120.7120.1

ava:Retirees, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value7572636060
Percentage of DefinedBenefitPlanBenefitObligation236.4210.8213.4183.5176.2

us-gaap:DefinedBenefitPlanBenefitObligation us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value161159134132136138
Percentage of DefinedBenefitPlanBenefitObligation502.3461.1448.3404.2396.30.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value826742671716666613
Percentage of DefinedBenefitPlanBenefitObligation2576.32149.02246.12178.61935.80.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value37383732
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value223217210205
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter602.3568.9559.4636.6

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value6.616.4426.7666.856
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value42393736
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths641.3615.4560.4538.4

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value7.1647.2446.746.288
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value43413938
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive610.7576.6584.6617.6

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value7.0217.0886.6886.223
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value43403938
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour614.6574.6583.4622.4

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value6.8916.9656.5666.093
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value42403838
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree616.4583.7585.3633.7

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value6.86.7826.3937.064
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value42403837
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo627.5591.0602.0532.5

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value6.86.77.16.856
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value42222222
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear617.6328.4309.9320.9

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-30
Value42
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear100.0

us-gaap:DefinedBenefitPlanFundedStatusOfPlan us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanFundedStatusOfPlan

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-109.06-114.443-97.201-94.994-103.088
Percentage of DefinedBenefitPlanFundedStatusOfPlan100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-104.891-100.319-127.578-110.909-125.558
Percentage of DefinedBenefitPlanFundedStatusOfPlan96.287.7131.3116.8121.8

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear ava:SurgicalMedicals, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear

ava:PostAge65, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6.250.0650.06250.0650.07
Percentage of DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear100.0100.0100.0100.0100.0

ava:PreAge65, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6.250.05750.060.0650.07
Percentage of DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear100.088.596.0100.0100.0

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value710644586624583
Percentage of DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage us-gaap:DefinedBenefitPlanByPlanAssetCategories

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage

ava:AbsoluteReturn


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value9.00.090.10.10.1
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage100.0100.0100.0100.0100.0

us-gaap:DebtSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value49.00.490.450.450.45
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage544.4544.4450.0450.0450.0

us-gaap:EquitySecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value35.00.350.370.370.37
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage388.9388.9370.0370.0370.0

us-gaap:RealEstate


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value7.00.070.080.080.08
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage77.877.880.080.080.0

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType

us-gaap:DebtSecurities, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value40.00.40.40.40.4
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage444.4444.4400.0400.0400.0

us-gaap:EquitySecurities, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value60.00.60.60.60.6
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage666.7666.7600.0600.0600.0

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage us-gaap:StatementScenario, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType

srt:ScenarioForecast, ava:AbsoluteReturn, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-03-31
Value0
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage0.0

srt:ScenarioForecast, us-gaap:DebtSecurities, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-03-31
Value40.0
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage0.0

srt:ScenarioForecast, us-gaap:EquitySecurities, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-03-31
Value55.0
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage0.0

srt:ScenarioForecast, us-gaap:RealEstate, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-03-31
Value5.0
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage0.0

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1 ava:SurgicalMedicals, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1

ava:PostAge65, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value5.00.050.050.050.05
Percentage of DefinedBenefitPlanUltimateHealthCareCostTrendRate1100.0100.0100.0100.0100.0

ava:PreAge65, us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value5.00.050.050.050.05
Percentage of DefinedBenefitPlanUltimateHealthCareCostTrendRate1100.0100.0100.0100.0100.0

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset

ava:NaturalGasExchangeAgreements, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2021-06-302021-03-312020-12-312020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.1190.0950.0750.0260.0270.0430.0450.1230.0310.0220.0250.0470.1830.090.0790.0990.0690.0250.0120.2590.6780.6920.0010.791.349
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ForeignExchangeContract, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value0.0070.0070.0360.00.00.0150.00.0160.0060.0010.00.00.0050.0250.0110.00.0020.0080.0040.0140.0010.006
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset0.00.0138.50.00.012.20.064.012.80.50.00.07.2100.091.70.00.31.2400.01.80.10.0

us-gaap:InterestRateSwap, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2021-06-302021-03-312020-12-312019-12-312019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-12-312013-12-31
Value1.9665.0840.9520.9630.9692.2840.440.1290.01.6312.5742.1451.8535.1944.3480.3860.1870.4430.01.0027.9140.5060.0
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset1652.15351.61269.33566.72153.31856.91419.4586.40.03470.21406.62383.32345.65246.56301.41544.01558.3171.00.0144.8791400.037.50.0

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value37232331333041343133363742604540365250335076747680969751
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset31150.425049.530905.30.00.0118888.5153488.980730.270562.227264.2117590.3168190.9171464.0129251.124758.544455.646801.353123.273255.1133220.0422150.029580.711008.011016.88016300.012197.67195.00.0

us-gaap:DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:FairValueMeasurementsRecurring, us-gaap:EnergyRelatedDerivative


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value341822313340
Percentage of DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset29398.319597.929536.00.00.0149822.2

us-gaap:DerivativeAssets us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeAssets

us-gaap:ForeignExchangeContract, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2020-12-312020-03-312019-12-312019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value0.030.00.0970.0330.00.0260.00.0160.0310.1870.0370.00.0020.00.0640.00.00.00.00.00.001
Percentage of DerivativeAssets100.00.0100.0100.00.0100.00.0100.0100.0100.0100.00.0100.00.0100.00.00.00.00.00.0100.0

us-gaap:InterestRateSwap, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2021-06-302021-03-312019-12-312019-06-302019-03-312018-12-312017-12-31
Value1.3182.5360.5890.4332.806104.903
Percentage of DerivativeAssets0.00.0607.21312.10.00.015816.1

us-gaap:DerivativeAssets us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:FairValueMeasurementsRecurring, us-gaap:EnergyRelatedDerivative


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value6.4012.1871.4933.7390.9441.094
Percentage of DerivativeAssets0.00.04976.70.00.01127.8

us-gaap:DerivativeAssetsLiabilitiesAtFairValueNet

us-gaap:DerivativeAssetsLiabilitiesAtFairValueNet


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value-29.983-12.902-49.912-57.202-69.184-83.566-28.833-48.298-35.671-12.364-3.8574.163-3.838-26.94-47.553-52.792-46.445-37.032-44.432-117.332-95.955-97.142-85.091-90.035-60.773-95.117-86.355-22.677-4.527108.189-9.99-24.244-12.977-44.762-60.673-82.163-108.038-128.893-84.328-45.619-64.425
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeAssetsLiabilitiesAtFairValueNet us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk

ava:OtherPropertyAndInvestmentsNetAndOtherNoncurrentAssets, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-09-302018-06-30
Value3.0171.4620.5963.1730.3052.4460.9230.0070.015
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet-10.1-11.3-1.2-5.5-0.4-2.9-3.20.2-0.4

ava:OtherPropertyAndInvestmentsNetAndOtherNoncurrentAssets, us-gaap:InterestRateSwap


Derivative
Period End2021-06-302021-03-312019-09-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value1.3180.7930.6410.7494.84318129.1542.5763.454.0316.6385.3570.023
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet-4.4-6.1-1.3-6.1-125.6433.1-320.8-34.0-5.4-6.5-8.7-17.9-12.1-0.0

us-gaap:OtherCurrentAssets, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value3.3840.7250.8970.5660.6391.7660.1710.240.3350.250.270.8770.0960.9611.2640.1270.1570.5571.8950.720.683
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet-11.3-5.6-1.8-1.0-0.9-2.1-0.6-0.5-0.9-2.0-7.021.1-2.5-3.6-2.7-0.2-0.3-1.5-4.3-0.6-0.8

us-gaap:OtherCurrentAssets, us-gaap:ForeignExchangeContract


Derivative
Period End2020-12-312019-12-312019-06-302019-03-312018-09-302018-03-312017-12-312017-06-302017-03-312016-09-302016-03-312014-06-302014-03-312013-12-312013-09-302012-06-302011-12-31
Value0.030.0970.0330.00.0260.0160.0310.1870.0370.0020.0640.1350.0170.0010.0180.0410.032
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet-0.1-0.3-0.1-0.00.6-0.1-0.1-0.4-0.1-0.0-0.1-3.00.20.0-0.2-0.0-0.0

us-gaap:OtherCurrentAssets, us-gaap:InterestRateSwap


Derivative
Period End2021-03-312019-12-312019-06-302019-03-312018-12-312018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value1.7430.5890.4332.0575.2833.932.3272.3885.4183.7483.393
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet-13.5-2.0-1.2-16.6-137.0-14.6-4.9-4.5-11.7-10.1-7.6

us-gaap:OtherCurrentLiabilities, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value-2.869-1.576-2.483-4.398-3.064-2.539-3.103-3.109-4.503-4.035-3.908-6.853-7.789-8.848
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet9.612.25.07.74.43.010.86.412.632.6101.3-164.6202.918.6

us-gaap:OtherCurrentLiabilities, us-gaap:ForeignExchangeContract


Derivative
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302018-12-312018-06-302017-09-302016-12-312016-06-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302012-12-31
Value-0.088-0.022-0.045-0.018-0.067-0.021-0.045-0.005-0.051-0.023-0.023-0.017-0.065-0.07-0.01-0.02-0.28-0.027
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet0.30.20.10.00.10.01.20.10.10.10.00.00.10.10.00.01.20.1

us-gaap:OtherCurrentLiabilities, us-gaap:InterestRateSwap


Derivative
Period End2021-06-302021-03-312020-12-312020-03-312019-12-312019-06-302019-03-312017-12-312017-03-312016-12-312016-09-302016-06-302015-12-31
Value-30.319-7.068-11.525-20.0-7.825-4.771-0.524-34.447-4.969-6.025-0.341-32.842-19.264
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet101.154.823.123.927.113.44.272.413.413.60.334.222.6

us-gaap:OtherNoncurrentLiabilities, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value-4.426-4.698-6.189-0.008-0.024-1.187-1.658-5.55-1.319-3.439-3.475-3.568-4.771-8.934-11.802-11.087-12.419-13.289-19.422-14.722-18.208-21.569-24.074-21.122-20.163-22.093-13.96-10.528-15.199-18.356-19.73-26.311
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet14.836.412.40.00.04.13.415.610.789.2-83.593.017.718.822.423.933.529.916.615.318.725.326.734.821.225.661.6232.6-146.2-224.2197.558.8

us-gaap:OtherNoncurrentLiabilities, us-gaap:InterestRateSwap


Derivative
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-06-302015-12-31
Value-4.261-31.238-56.498-67.038-65.148-18.498-44.391-21.648-9.542-6.861-4.448-4.901-1.384-1.522-42.117-30.679
Percentage of DerivativeAssetsLiabilitiesAtFairValueNet33.062.698.896.978.064.291.960.777.2177.9-106.8127.75.13.243.936.1

us-gaap:DerivativeCollateralRightToReclaimCash

us-gaap:DerivativeCollateralRightToReclaimCash


Derivative
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value254.814.3360.02.474.4341.40.0372612
Percentage of DerivativeCollateralRightToReclaimCash100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:DerivativeFairValueAmountOffsetAgainstCollateralNet

us-gaap:DerivativeFairValueAmountOffsetAgainstCollateralNet


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value126.6968.6664.4778.0112610123137511922446250514344821359548483857441310-0.5028.7321014109.7079.47415
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeFairValueAmountOffsetAgainstCollateralNet us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk

ava:OtherPropertyAndInvestmentsNetAndOtherNoncurrentAssets, us-gaap:CommodityContract


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312018-09-302018-06-30
Value-1.072-0.8530.00.00.00.0
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet-23.9-10.60.00.00.00.0

us-gaap:OtherCurrentAssets, us-gaap:CommodityContract


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value-4.551-2.116-0.6950.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet-101.7-26.4-2.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCurrentLiabilities, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value6.1662.7860.4870.00.03.3783.505202437131417
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet51.341.65.60.00.033.328.367.264.573.068.562.827.9

us-gaap:OtherCurrentLiabilities, us-gaap:InterestRateSwap


Derivative
Period End2021-06-302021-03-312020-12-312020-03-312019-12-312019-06-302019-03-312017-12-312017-03-312016-12-312016-09-302016-06-302015-12-31
Value5.853.918.05121.3160.00.028109.7318.692163.88
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet48.758.492.949.113.00.00.046.423.121.710.612.18.0

us-gaap:OtherNoncurrentLiabilities, us-gaap:CommodityContract


Derivative
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value0.1290.00.00.00.05.21410136.0877.7244.322104.5693.9362.8173.637.9149.8767.711109.9447.0923.9822.390.8863.0510.05.7565.2920.0
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet1.50.00.00.00.016.727.925.931.534.59.816.19.17.76.48.19.67.38.022.320.418.36.95.46.530.2-0.065.950.80.0

us-gaap:OtherNoncurrentLiabilities, us-gaap:InterestRateSwap


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-06-302015-12-31
Value1010145.4548.885.032.860.530.00.594.9376.01810030
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet225.6137.153.553.771.716.17.61.00.02.611.29.674.162.1

us-gaap:DerivativeFairValueAmountOffsetAgainstCollateralNet us-gaap:DerivativeInstrumentRisk

us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value6.1662.7860.616-5.623-2.969-0.6953.3783.50526345119211627159.7677.5439.8581718191412167.44415
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet51.341.67.1-125.6-37.1-2.633.328.383.992.499.0100.097.437.544.031.319.017.322.021.813.920.829.925.842.212.834.9

us-gaap:InterestRateSwap


Derivative
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1010276.778.885.032.860.530.00.5927343441363464117763436225028
Percentage of DerivativeFairValueAmountOffsetAgainstCollateralNet225.6137.1102.666.771.716.17.61.00.02.662.556.068.781.082.778.078.286.179.270.174.257.887.265.1

us-gaap:DerivativeFairValueOfDerivativeAsset

us-gaap:DerivativeFairValueOfDerivativeAsset


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value4428243534354335323646555574514546636134527776778297996691112899485858982942786595035
Percentage of DerivativeFairValueOfDerivativeAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

ava:OtherPropertyAndInvestmentsNetAndOtherNoncurrentAssets, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-09-302018-06-30
Value5.4422.5981.7558.2212.7016.0726.3690.0070.015
Percentage of DerivativeFairValueOfDerivativeAsset12.29.17.123.07.717.314.70.00.0

ava:OtherPropertyAndInvestmentsNetAndOtherNoncurrentAssets, us-gaap:InterestRateSwap


Derivative
Period End2021-06-302021-03-312019-09-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value1.3184.6134.1272.5035.28318129.5124.885.3465.6766.7545.7540.023
Percentage of DerivativeFairValueOfDerivativeAsset2.916.211.66.811.332.222.312.79.511.612.110.69.40.0

us-gaap:OtherCurrentAssets, us-gaap:CommodityContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31<