AEE


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

Table of contents



us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities

us-gaap:CommonStockSharesOutstanding
us-gaap:ConsolidatedEntities

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:GainLossOnInvestments
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
dei:LegalEntity

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility

us-gaap:InterestExpense
dei:LegalEntity
dei:LegalEntity
us-gaap:NetIncomeLoss
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
us-gaap:StatementEquityComponents

us-gaap:OperatingExpenses
dei:LegalEntity

us-gaap:OperatingIncomeLoss
dei:LegalEntity

us-gaap:OtherIncome
dei:LegalEntity

us-gaap:OtherNonoperatingIncomeExpense
dei:LegalEntity
dei:LegalEntity
us-gaap:PreferredStockDividendsIncomeStatementImpact

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

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

us-gaap:Revenues
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidationItems
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:RegulatoryAsset
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:RegulatoryAsset, us-gaap:SubsequentEventType
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ProductOrService

us-gaap:Assets
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:Liabilities

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

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

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

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:ConsolidatedEntities
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis

us-gaap:AccountsReceivableNetCurrent
dei:LegalEntity

us-gaap:InventoryNet
dei:LegalEntity

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

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

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
dei:LegalEntity

us-gaap:PropertyPlantAndEquipmentNet
dei:LegalEntity

us-gaap:Goodwill

us-gaap:OtherAssetsNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:FinancialInstrument
us-gaap:EquitySecuritiesFvNi

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent
dei:LegalEntity

us-gaap:ContractWithCustomerLiabilityCurrent
dei:LegalEntity

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

us-gaap:LongTermDebtCurrent
dei:LegalEntity

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

us-gaap:TaxesPayableCurrent
dei:LegalEntity

us-gaap:LongTermDebt
dei:LegalEntity

us-gaap:LongTermDebtNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtAndCapitalLeaseObligations
us-gaap:FairValueByMeasurementBasis

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

us-gaap:MinorityInterest

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

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

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

us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities

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

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

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
us-gaap:ConsolidatedEntities

us-gaap:MinorityInterest
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueNewIssues
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
us-gaap:StatementEquityComponents
us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
dei:LegalEntity

us-gaap:IncreaseDecreaseInInventories
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity
dei:LegalEntity
us-gaap:NetIncomeLoss
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

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

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

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

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

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity

us-gaap:PaymentsOfDividendsCommonStock

us-gaap:EffectiveIncomeTaxRateContinuingOperations
dei:LegalEntity

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

us-gaap:DeferredTaxAssetsNet
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfShortTermDebt
dei:LegalEntity
us-gaap:LossContingenciesByNatureOfContingency
aee:AggregateNuclearPowerIndustryInsurancePolicyLimitForLossesFromTerroristAttacksWithinTwelveMonthPeriod
us-gaap:LossContingenciesByNatureOfContingency
aee:AmountOfAdditionalWeeklyIndemnityCoverageCommencingAfterInitialIndemnityCoverage
us-gaap:LossContingenciesByNatureOfContingency
aee:AmountOfWeeklyIndemnityCoverageThereafterNotExceedingPolicyLimit
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
aee:AmountofMegawatts
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:LossContingenciesByNatureOfContingency
aee:AmountofWeeklyIndemnityCoverageCommencingTwelveWeeksAfterPowerOutage
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility
aee:AmountsPreviouslyDeferredUnderPISA
dei:LegalEntity
aee:AnnualInvestmentInEnergyEfficiencyPrograms
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding
aee:AtchisonRenewableEnergyCenterPurchasePrice
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding
aee:COVID19PandemicCosts

aee:DecommissioningCost

aee:DefinedBenefitPlanNonServiceCostOrIncomeComponents
dei:LegalEntity
us-gaap:RetirementPlanType

aee:DefinedBenefitPlanNonserviceCostorIncomeComponents
dei:LegalEntity
us-gaap:RetirementPlanType
dei:LegalEntity
aee:DefinedBenefitPlanNonserviceCostorIncomeComponentsTracker

aee:Donations
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility
dei:LegalEntity
aee:EffectiveIncomeTaxRateReconciliationNondeductibleExpenseAmortizationOfExcessDeferredTaxesPercent

aee:EffectiveIncomeTaxRateReconciliationNondeductibleExpenseAmortizationofExcessDeferredTaxesPercent
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased, us-gaap:RelatedPartyTransaction
aee:EnergySupplyAgreementsAmount
dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType
aee:EstimatedNuclearGeneratorRepairs
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk
aee:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityChangeInRealizedUnrealizedGainLossStillHeld
us-gaap:DerivativeInstrumentRisk
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk
aee:FairValueMeasurementWithUnobservableInputsReconciliationRecurringRealizedAndUnrealizedGainsLossesIncludedInRegulatoryAssetsLiabilities
us-gaap:DerivativeInstrumentRisk
dei:LegalEntity
aee:FinancialAssistanceProgramCosts
us-gaap:StatementEquityComponents
aee:ForwardContractIndexedToIssuersEquitySettlement
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:SubsequentEventType
aee:ICCStaffRecommendedRateBase
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:RegulatoryAsset
aee:ICCStaffRecommendedRateIncreaseDecrease
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:SubsequentEventType
us-gaap:LossContingenciesByNatureOfContingency
aee:MaximumAnnualPaymentPerIncidentAtLicensedCommercialNuclearReactor

aee:Otherrevenuesnotfromcontractswithcustomers
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

aee:PeakShortTermBorrowingsInterestRate
dei:LegalEntity
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtType
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:SubsequentEventType
aee:ProjectPlacedInServiceAmount
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased, us-gaap:RelatedPartyTransaction
aee:RelatedPartyLongTermContractForPurchaseOfElectricPower
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased, us-gaap:RelatedPartyTransaction
aee:RelatedPartyLongTermContractForPurchaseOfElectricPowerRate

aee:Revenuesfromalternativerevenueprograms
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:AwardDate, us-gaap:AwardType
aee:SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsGrantedinPeriodFairValue
us-gaap:LossContingenciesByNatureOfContingency
aee:SubLimitOfAmountOfWeeklyIndemnityCoverageThereafterNotExceedingPolicyLimitForNonNuclearEvents
us-gaap:LossContingenciesByNatureOfContingency
aee:ThresholdAmountForRetrospectiveInsuranceAssessmentForCoveredLossUnderPublicLiabilityAndNuclearWorkerLiabilityInsurancePolicy

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs
dei:LegalEntity

us-gaap:AmortizationOfFinancingCostsAndDiscounts
dei:LegalEntity

us-gaap:AssetRetirementObligationAccretionExpense
dei:LegalEntity

us-gaap:AssetRetirementObligationLiabilitiesIncurred
dei:LegalEntity

us-gaap:AssetRetirementObligationLiabilitiesSettled
dei:LegalEntity

us-gaap:AssetRetirementObligationRevisionOfEstimate
dei:LegalEntity

us-gaap:CapitalExpendituresIncurredButNotYetPaid
dei:LegalEntity

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

us-gaap:DepreciationAmortizationAndAccretionNet
dei:LegalEntity
dei:LegalEntity, us-gaap:TradingActivityByType
us-gaap:DerivativeNonmonetaryNotionalAmountEnergyMeasure
us-gaap:TradingActivityByType
dei:LegalEntity, us-gaap:TradingActivityByType
us-gaap:DerivativeNonmonetaryNotionalAmountMass
us-gaap:TradingActivityByType
dei:LegalEntity, us-gaap:TradingActivityByType
us-gaap:DerivativeNonmonetaryNotionalAmountVolume
us-gaap:TradingActivityByType
us-gaap:StatementEquityComponents
us-gaap:DividendsCommonStockCash
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:DividendsPreferredStockCash
dei:LegalEntity
us-gaap:EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepreciation

us-gaap:EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount

us-gaap:EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitPercent

us-gaap:EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
dei:LegalEntity

us-gaap:EffectiveIncomeTaxRateReconciliationTaxCredits
dei:LegalEntity

us-gaap:EffectiveIncomeTaxRateReconciliationTaxCreditsInvestment
dei:LegalEntity

us-gaap:ExciseAndSalesTaxes
dei:LegalEntity
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements
us-gaap:DerivativeInstrumentRisk
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements
us-gaap:DerivativeInstrumentRisk

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInAccruedTaxesPayable
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherOperatingAssets
dei:LegalEntity

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities
dei:LegalEntity

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations
dei:LegalEntity

us-gaap:IncreaseDecreaseInReceivables
dei:LegalEntity

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
dei:LegalEntity

us-gaap:IncrementalCommonSharesAttributableToEquityForwardAgreements

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
dei:LegalEntity, us-gaap:RelatedPartyTransaction
us-gaap:InterestExpenseRelatedParty

us-gaap:InterestIncomeSecuritiesTaxExempt
dei:LegalEntity

us-gaap:OtherAmortizationOfDeferredCharges
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherInterestAndDividendIncome
dei:LegalEntity

us-gaap:OtherNoncashIncomeExpense
dei:LegalEntity

us-gaap:OtherNoninterestExpense
dei:LegalEntity

us-gaap:PaymentOfFinancingAndStockIssuanceCosts
dei:LegalEntity
dei:LegalEntity
us-gaap:PaymentsForAdvanceToAffiliate

us-gaap:PaymentsForNuclearFuel
dei:LegalEntity

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsForRepurchaseOfRedeemableNoncontrollingInterest
dei:LegalEntity
us-gaap:PaymentsForRepurchaseOfRedeemablePreferredStock
dei:LegalEntity, us-gaap:StatementClassOfStock

us-gaap:PaymentsOfDividendsMinorityInterest
dei:LegalEntity
us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:PaymentsToAcquireProjects
dei:LegalEntity

us-gaap:PaymentsToInvestInDecommissioningFund
dei:LegalEntity
dei:LegalEntity
us-gaap:ProceedsFromCollectionOfAdvanceToAffiliate
dei:LegalEntity
us-gaap:ProceedsFromContributionsFromParent
dei:LegalEntity, us-gaap:StatementEquityComponents

us-gaap:ProceedsFromDecommissioningFund
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfCommonStock
us-gaap:SubsidiarySaleOfStock
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:ProceedsFromIssuanceOfSecuredDebt
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:ProceedsFromIssuanceOfUnsecuredDebt

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity
dei:LegalEntity
us-gaap:ProceedsFromRepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths

us-gaap:ProvisionForDoubtfulAccounts
dei:LegalEntity

us-gaap:PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility
us-gaap:PublicUtilitiesRequestedRateIncreaseDecreaseAmount
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:RegulatoryAsset, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:RelatedPartyTransaction
us-gaap:RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:RevenueFromRelatedParties
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:SubsegmentsConsolidationItems
dei:LegalEntity, us-gaap:RelatedPartyTransaction
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments, us-gaap:SubsegmentsConsolidationItems
us-gaap:ConsolidationItems, us-gaap:SubsegmentsConsolidationItems
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:MajorCustomers
us-gaap:RevenueNotFromContractWithCustomer
dei:LegalEntity, us-gaap:ConsolidationItems, us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:MajorCustomers
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:MajorCustomers, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:MajorCustomers, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:MajorCustomers, us-gaap:ProductOrService

us-gaap:RevenueNotFromContractWithCustomerOther
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtWeightedAverageInterestRateOverTime

us-gaap:ShorttermDebtAverageOutstandingAmount
dei:LegalEntity
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtType

us-gaap:ShorttermDebtMaximumAmountOutstandingDuringPeriod
dei:LegalEntity
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtType

us-gaap:StockIssued1

us-gaap:StockIssuedDuringPeriodSharesNewIssues

us-gaap:StockIssuedDuringPeriodSharesOther
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueDividendReinvestmentPlan

us-gaap:StockIssuedDuringPeriodValueOther
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StockRedeemedOrCalledDuringPeriodValue
us-gaap:StatementEquityComponents

us-gaap:TaxesExcludingIncomeAndExciseTaxes
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseDepreciationAndAmortization
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseFuelUsed
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseGasAndPetroleumPurchased
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility

us-gaap:UtilitiesOperatingExpensePurchasedPower
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility

aee:AccountsReceivableBalancesThatAre30DaysOrMorePastDueOrPartOfADeferredPaymentArrangement
dei:LegalEntity

aee:Accumulateddepreciationfinancingobligations
dei:LegalEntity
aee:BondsIssuableBasedOnCoverageRatio
dei:LegalEntity
aee:CommonStockEquityToCapitalizationRatio
dei:LegalEntity, us-gaap:Range

aee:CommonStockSharesAuthorizedUnder401kPlan

aee:CommonStockSharesAuthorizedUnderDRPlusPlan

aee:CommonStockSharesIssuedThroughForwardSaleAgreement
us-gaap:SubsequentEventType

aee:CommonStockValueIssuedThroughForwardSaleAgreement
us-gaap:SubsequentEventType

aee:Corporateownedlifeinsuranceborrowings
dei:LegalEntity
dei:LegalEntity
aee:DebtEquityMarketableAndOtherSecuritiesAvailableForSale
dei:LegalEntity
aee:DebtEquityMarketableAndOtherSecuritiesAvailableForSaleAmortizedCost
dei:LegalEntity
aee:DebtEquityMarketableAndOtherSecuritiesAvailableForSaleUnrealizedGain
dei:LegalEntity
aee:DebtEquityMarketableAndOtherSecuritiesAvailableForSaleUnrealizedLoss
dei:LegalEntity
aee:DebtInstrumentUnamortizedDiscountorPremiumandDebtIssuanceCosts

aee:DefinedBenefitPlanEstimatedFutureEmployerContributionsOverNextFiveYears
dei:LegalEntity, us-gaap:RetirementPlanType
aee:DefinedBenefitPlanFutureFundingRequirementPercentage
dei:LegalEntity, us-gaap:Range
aee:EstimatedCapitalCostsToComplyWithExistingAndKnownFederalAndStateAirEmissionsRegulations
dei:LegalEntity, us-gaap:Range, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:Range
dei:LegalEntity, us-gaap:Range
aee:Estimatedcapitalcoststocomplywithexistingandknownfederalandstateairemissionstandards.
dei:LegalEntity, us-gaap:Range, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:Range

aee:GrossAssetValueFinancingObligation
us-gaap:ConsolidatedEntities
aee:GuaranteesOutstanding
us-gaap:LossContingenciesByNatureOfContingency
aee:InsuranceAggregateMaximumCoverage
us-gaap:LossContingenciesByNatureOfContingency
aee:InsuranceMaximumCoveragePerIncident
us-gaap:DebtInstrument
aee:LineOfCreditFacilityCovenantTermsDefaultProvisionMaximumIndebtedness
us-gaap:CreditFacility
aee:LineOfCreditFacilityMaximumBorrowingCapacityPerLender

aee:MaximumValueOfSharesToBeIssuedUnderATMProgram
us-gaap:DebtInstrument
aee:NetLiquidityAvailable
dei:LegalEntity, us-gaap:FinancialInstrument
aee:NetReceivablesPayablesFromPendingSecuritiesSalesInterestandSecuritiesPurchasesCostBasis
dei:LegalEntity, us-gaap:FinancialInstrument
aee:NetReceivablesPayablesFromPendingSecuritiesSalesInterestandSecuritiesPurchasesFairValue

aee:Payablesforpurchasedreceivables
dei:LegalEntity

aee:PeriodEndNetCashSettlementPrice

aee:PeriodEndNetShareSettlementPrice
dei:LegalEntity
aee:PreferredStockIssuableBasedOnCoverageRatio

aee:PropertyPlantAndEquipmentNetBeforeConstructionWorkInProgress
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility
aee:RateBase
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
aee:RatioofIndebtednesstoTotalAssets

aee:ReceivablesPayablesAndAccruedIncomeNet

aee:RestrictedCashandCashEquivalentsNuclearDecommissioningTrustFund
dei:LegalEntity
dei:LegalEntity
aee:RetiredBondCapacity

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity
us-gaap:AccountsPayableRelatedPartiesCurrent
dei:LegalEntity, us-gaap:RelatedPartyTransaction
us-gaap:ConsolidatedEntities
dei:LegalEntity
us-gaap:AccountsReceivableRelatedPartiesCurrent
dei:LegalEntity, us-gaap:RelatedPartyTransaction
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:AccrualForEnvironmentalLossContingencies
us-gaap:LossContingenciesByNatureOfContingency
dei:LegalEntity
us-gaap:AccruedEnvironmentalLossContingenciesNoncurrent

us-gaap:AccumulatedDeferredInvestmentTaxCredit
dei:LegalEntity

us-gaap:AllowanceForDoubtfulAccountsReceivable
dei:LegalEntity

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity

us-gaap:AssetRetirementObligation
dei:LegalEntity
dei:LegalEntity, us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:RealEstateAndAccumulatedDepreciationDescriptionOfProperty

us-gaap:AssetRetirementObligationCurrent
dei:LegalEntity

us-gaap:AssetRetirementObligationsNoncurrent
dei:LegalEntity

us-gaap:AssetsFairValueDisclosure
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel
dei:LegalEntity, us-gaap:FinancialInstrument
us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis
dei:LegalEntity, us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtSecurities
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:CapitalizedComputerSoftwareAccumulatedAmortization
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:CapitalizedComputerSoftwareGross
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:CashSurrenderValueOfLifeInsurance
dei:LegalEntity

us-gaap:CreditDerivativeMaximumExposureUndiscounted
dei:LegalEntity
dei:LegalEntity
us-gaap:DebtInstrumentCarryingAmount
dei:LegalEntity
us-gaap:DebtInstrumentUnamortizedDiscountPremiumNet
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:DebtSecuritiesAvailableForSaleAndHeldToMaturity
us-gaap:FairValueByMeasurementBasis

us-gaap:DecommissioningFundInvestments
dei:LegalEntity
dei:LegalEntity, us-gaap:FinancialInstrument

us-gaap:DecommissioningTrustAssetsAmount

us-gaap:DeferredCompensationLiabilityClassifiedNoncurrent
dei:LegalEntity
us-gaap:DeferredFinanceCostsNet
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis
us-gaap:ConsolidatedEntities
us-gaap:DeferredIncomeTaxesAndOtherAssetsNoncurrent

us-gaap:DeferredIncomeTaxesAndOtherTaxLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:DeferredTaxAssetsCharitableContributionCarryforwards
dei:LegalEntity
dei:LegalEntity
us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsRegulatoryAssetsAndLiabilities
dei:LegalEntity

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits
dei:LegalEntity
dei:LegalEntity
us-gaap:DeferredTaxLiabilitiesDeferredExpense

us-gaap:DeferredTaxLiabilitiesOther
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment
dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmountsRecognizedInBalanceSheet
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
aee:DefinedBenefitPlanFundingSource, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
aee:DefinedBenefitPlanFundingSource, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
aee:DefinedBenefitPlanFundingSource, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
aee:DefinedBenefitPlanFundingSource, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
aee:DefinedBenefitPlanFundingSource, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
aee:DefinedBenefitPlanFundingSource, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo

us-gaap:DefinedBenefitPlanFundedStatusOfPlan
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
us-gaap:Range, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations
us-gaap:RetirementPlanType
us-gaap:Range, us-gaap:DerivativeInstrumentRisk, us-gaap:MeasurementInputType, us-gaap:ValuationTechnique
us-gaap:DerivativeAssetLiabilityNetMeasurementInput
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:DerivativeLiabilities
dei:LegalEntity
us-gaap:DueFromRelatedPartiesCurrent
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:ConsolidatedEntities
dei:LegalEntity
us-gaap:DueToRelatedPartiesCurrent
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:EnergyRelatedInventoryCoal
dei:LegalEntity

us-gaap:EnergyRelatedInventoryGasStoredUnderground
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:EquityMethodInvestments
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
dei:LegalEntity, us-gaap:FinancialInstrument
us-gaap:EquitySecuritiesFvNiCost
dei:LegalEntity, us-gaap:DerivativeInstrumentRisk
us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
us-gaap:DerivativeInstrumentRisk
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
dei:LegalEntity, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:ForwardContractIndexedToIssuersEquitySettlementAlternativesCashAtFairValue
dei:LegalEntity
us-gaap:HeldToMaturitySecurities

us-gaap:InterestPayableCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:InvestmentsFairValueDisclosure
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis

us-gaap:LiabilitiesOtherThanLongtermDebtNoncurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument
us-gaap:DebtInstrument

us-gaap:LoansInsurancePolicy
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtFairValue
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
dei:LegalEntity

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:Range, us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingencyEstimateOfPossibleLoss
dei:LegalEntity, us-gaap:FinancialInstrument
us-gaap:MarketableSecurities

us-gaap:NoncontrollingInterestInVariableInterestEntity

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

us-gaap:OtherReceivablesNetCurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities
us-gaap:LossContingenciesByNatureOfContingency
us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent
dei:LegalEntity
dei:LegalEntity
us-gaap:PreferredStockValue

us-gaap:PublicUtilitiesInventory
dei:LegalEntity
dei:LegalEntity, us-gaap:PropertyPlantAndEquipmentByType
us-gaap:PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress
us-gaap:PropertyPlantAndEquipmentByType
dei:LegalEntity, us-gaap:DebtInstrument
us-gaap:RatioOfIndebtednessToNetCapital1
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrument
us-gaap:Range, us-gaap:DebtInstrument

us-gaap:RegulatedEntityOtherAssetsNoncurrent
dei:LegalEntity

us-gaap:RegulatoryAssets
dei:LegalEntity
dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding
us-gaap:PublicUtilitiesRegulatoryProceeding

us-gaap:RegulatoryAssetsCurrent
dei:LegalEntity

us-gaap:RegulatoryAssetsNoncurrent

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

us-gaap:RegulatoryLiabilityCurrent
dei:LegalEntity
dei:LegalEntity, us-gaap:LitigationCase, us-gaap:RegulatoryAgency
us-gaap:LitigationCase, us-gaap:RegulatoryAgency

us-gaap:RegulatoryLiabilityNoncurrent
dei:LegalEntity

us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue
dei:LegalEntity

us-gaap:RestrictedCashAndCashEquivalentsNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities

us-gaap:SecuritiesLoaned
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
us-gaap:AwardType, us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized

us-gaap:ShortTermBorrowings
dei:LegalEntity
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ConsolidatedEntities
us-gaap:FairValueByMeasurementBasis
us-gaap:ShortTermDebtType

us-gaap:ShortTermDebtWeightedAverageInterestRate
dei:LegalEntity
dei:LegalEntity, us-gaap:ShortTermDebtType
us-gaap:ConsolidatedEntities
us-gaap:ShortTermDebtType
dei:LegalEntity, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:ShorttermDebtFairValue
dei:LegalEntity, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:FairValueByMeasurementBasis

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

us-gaap:UnbilledReceivablesCurrent
dei:LegalEntity

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

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

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

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

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

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

us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears
dei:LegalEntity
dei:LegalEntity, us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
us-gaap:LongTermPurchaseCommitmentByCategoryOfItemPurchased
dei:LegalEntity, us-gaap:ValuationAllowancesAndReservesType
us-gaap:ValuationAllowancesAndReservesBalance
us-gaap:ValuationAllowancesAndReservesType
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:VariableInterestEntityEntityMaximumLossExposureAmount

Plots across concepts


IncomeStatement
Comprehensive Income 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
Goodwill
PropertyPlantAndEquipmentNet
Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
Liabilities
Liabilities Current
Current Liabilities
Long Term Debt Current
Noncurrent Liabilities
Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent
Stockholders Equity
Accumulated Other Comprehensive Income Loss Net Of Tax
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
AccountsReceivable
Allowance For Doubtful Accounts Receivable Current

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:CommonStockValue ███▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁3.03.03.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.0NANANA2.0NANANA
us-gaap:CommonStockSharesOutstanding █▇▆▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁257.1255.5253.3247.2247.1246.9246.2246.0245.8245.6244.5244.2243.6243.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.6242.2241.6241.1240.4NANANA237.4NANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁257.2255.9NA249.2247.9248.1NA247.5247.2246.4NA246.3245.8244.4NA244.7243.5NANA242.9NANANA243.9NANANA244.3NANANA245.1NANANA242.9NANANANANANANANANANANANANANA
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁256.1254.4NA247.1246.9246.4NA245.9245.6244.9NA244.1243.7242.9NA242.6242.6242.6NA242.6242.6242.6NA242.6242.6242.6NA242.6242.6242.6NA242.6242.6242.6NA242.6246.6242.6NA241.7241.2240.6NA239.3238.4237.6NANANANA
us-gaap:EarningsPerShareBasic ▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▆█▇▇▇█▇▇▆█▇▆▁█▇▄0.810.920.469999999999999751.480.990.590.381.480.730.780.281.460.980.62-0.241.190.790.420.131.520.610.430.121.420.610.450.21.210.610.40.151.250.39-0.6-4.761.540.87-1.66NANANANANANANANANANANANA
us-gaap:EarningsPerShareDiluted ▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▆█▇▇▇█▇▇▆█▇▆▁█▇▄0.80.910.459999999999999961.470.980.590.381.470.720.780.281.450.970.62-0.241.180.790.420.131.520.610.430.121.410.610.450.21.20.610.40.151.240.39-0.6-4.761.540.87-1.66NANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
 EBT Margin dei:LegalEntity aee:AmerenIllinoisCompany▄█▄▃▂▆▄▂▂▇▅▂▂▇▅▂▂▅▃▅▂▅▂▄▁▆▄▂▁▇▂▂▁▅▃▄▂▆▃▆▃█▅▆▄629.0823.0656.0589.0567.0723.0654.0564.0547.0762.0674.0564.0578.0760.0674.0575.0576.0703.0595.0676.0542.0677.0553.0655.0513.0745.0633.0572.0519.0774.0564.0547.0516.0684.0589.0648.0564.0724.0611.0745.0623.0808.0710.0746.0647.0NANANANANA
 Net profit Margin dei:LegalEntity aee:AmerenIllinoisCompany▄█▄▃▂▆▄▂▂▇▅▂▂▇▅▂▂▅▃▅▂▅▂▄▁▆▄▂▁▇▂▂▁▅▃▄▂▆▃▆▃█▅▆▄629.0823.0656.0589.0567.0723.0654.0564.0547.0762.0674.0564.0578.0760.0674.0575.0576.0703.0595.0676.0542.0677.0553.0655.0513.0745.0633.0572.0519.0774.0564.0547.0516.0684.0589.0648.0564.0724.0611.0745.0623.0808.0710.0746.0647.0NANANANANA
 Operating Margin dei:LegalEntity aee:AmerenIllinoisCompany▄█▄▃▂▆▄▂▂▇▅▂▂▇▅▂▂▅▃▅▂▅▂▄▁▆▄▂▁▇▂▂▁▅▃▄▂▆▃▆▃█▅▆▄629.0823.0656.0589.0567.0723.0654.0564.0547.0762.0674.0564.0578.0760.0674.0575.0576.0703.0595.0676.0542.0677.0553.0655.0513.0745.0633.0572.0519.0774.0564.0547.0516.0684.0589.0648.0564.0724.0611.0745.0623.0808.0710.0746.0647.0NANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
 TTM Greenblatt ROC _ _▇▇▇▇▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▆█▇▇▇█▇▇▁█▇▅▆█▇▇▇▆▇▇▇286.0316.0211.0494.0354.0241.0179.0520.0280.0288.0166.0533.0385.0273.0225.0581.0398.0254.0145.0691.0325.0220.0140.0626.0237.0256.0125.0561.0322.0246.0171.0567.0261.0185.0-1816.0635.0363.0-422.0148.0550.0316.0227.0198.089.0331.0298.0245.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:ComprehensiveIncomeNetOfTax ▇▇▇█▇▇▇█▇▇▆█▇▇▆▇▇▇▆█▇▇▆█▇▇▆▇▇▇▆▇▇▆▁█▇▄▆▇▇▆206.0234.0129.0368.0243.0147.098.0364.0179.0192.063.0359.0237.0152.0-57.0288.0195.0102.011.0368.0151.0103.031.0343.0154.0108.033.0293.0152.096.059.0292.0101.0-152.0-1166.0406.0216.0-388.00.0281.0137.068.0NANANANANANANANA
us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest ▁█▁█▁█▁█▁█▁█▁█▁█▁█▁█▁█1.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.0NANANANANANANANANANANANA0.09.0-1.0NA-5.02.01.0NANANANANANANANANA
us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest ▅▆▄█▆▄▄█▅▅▃█▆▄▁▇▅▄▂█▄▄207.0236.0130.0370.0244.0149.099.0366.0180.0194.064.0361.0238.0154.0-56.0290.0196.0104.012.0370.0152.0105.0NANANANANANANANANANANANA-1166.0415.0215.0-388.0-5.0283.0138.071.045.0-164.0146.0118.0NANANANA
us-gaap:GainLossOnInvestments █▁63.022.0NA47.0107.0-111.0NA10.026.064.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments ▇▇▇█▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▇█▇▇▇█▇▇▁█▇▅▆█▇▇▇▆▇▇239.0262.0137.0432.0294.0169.0119.0458.0219.0220.085.0464.0314.0195.0141.0495.0308.0161.059.0604.0240.0138.061.0553.0158.0176.067.0490.0250.0163.072.0494.0172.091.0-1917.0532.0264.0-533.043.0450.0224.0119.084.0-27.0238.0181.0NANANANA
us-gaap:IncomeTaxExpenseBenefit ▇▇▇▇▇▇▇▇▇▇▆▇▇▇██▇▇▇█▇▇▇█▇▇▇█▇▇▇█▇▇▁▇▇▅▆█▇▇▇▇▇▇31.027.021.063.050.021.024.092.039.027.016.0105.074.042.0200.0205.0114.057.026.0233.092.031.030.0208.059.066.020.0194.099.064.023.0187.066.035.0-762.0158.054.0-130.017.0163.085.045.030.0137.083.075.0NANANANA
us-gaap:InterestExpense ▄▄▅▅▅▃▃▄▄▄▄▄▄▄▄▄▄▄▃▄▃▃▃▂▃▃▁▂▃▃▅▃▄▄▅▆▆▆▆▆▅▆▇█▆█96.0100.0108.0110.0108.093.091.096.097.097.099.0101.0100.0101.096.097.099.099.095.097.095.095.091.087.089.088.075.085.089.092.0109.088.0100.0101.0110.0113.0112.0113.0115.0113.0104.0119.0120.0130.0115.0132.0NANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity aee:AmerenIllinoisCompany▅█▅▄▅▇▅▄▄▇▅▄▄▅▄▃▃▄▂▆▃▃▂▅▂▃▃▄▂▃▂▄▂▂▁▄▂▂▂▅▂▂86.0149.099.077.083.0120.096.065.062.0120.084.063.062.095.077.055.057.079.027.0119.046.060.033.098.032.054.046.075.029.054.022.077.032.032.012.071.033.028.026.098.038.034.0NANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity aee:UnionElectricCompany▄▃▂█▅▂▁█▄▃▁█▅▃▁▇▄▂▂▇▄▂▂▇▃▃▂▆▄▃▂▇▄▃▂▇▅▂▁▆▄▂111.047.0-3.0297.0152.0-10.0-20.0300.0107.039.0-22.0294.0168.038.0-36.0234.0120.05.07.0242.093.015.011.0240.062.042.0-5.0223.0127.048.033.0239.085.041.016.0237.0144.022.0-14.0191.091.022.0NANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionNANA36.034.036.037.041.032.037.036.035.035.033.033.037.031.033.030.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionSegment▁█41.046.0NANA36.037.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisGasNANA33.02.09.055.027.0-1.01.057.021.00.07.042.020.02.05.033.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisGasSegment▁█8.075.0NANA9.055.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisTransmissionNANA30.041.038.028.028.034.024.027.028.028.022.020.020.022.019.016.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisTransmissionSegment█▁37.028.0NANA38.028.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionNANA36.034.036.037.041.032.037.036.035.035.033.033.037.031.033.030.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionSegment▁█41.046.0NANA36.037.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisGasNANA33.02.09.055.027.0-1.01.057.021.00.07.042.020.02.05.033.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisGasSegment▁█8.075.0NANA9.055.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenTransmissionNANA48.062.059.047.046.053.042.044.043.048.036.037.034.038.034.034.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenTransmissionSegment█▁55.047.0NANA59.047.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:OtherSegmentNANA1.0-28.0-13.017.00.0-20.0-8.015.0-9.0-20.0-5.01.0-115.0-17.01.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:UnionElectricCompany▄▃▂█▅▂▁█▄▃▁█▅▃▁▇111.047.0-3.0297.0152.0-10.0-20.0300.0107.039.0-22.0294.0168.038.0-36.0234.0NA5.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLossAttributableToNoncontrollingInterest ▁█▁█▁█▁█▁█▁█▁█▁█▁█▁█▁█1.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.0NANANANANANANANANANA1.02.0NA0.0-1.02.01.02.01.03.02.03.03.04.0NANANANA
us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic ▅▆▄█▆▄▄█▅▅▃█▆▄▁▇▅▄207.0233.0115.0367.0243.0146.094.0364.0179.0191.068.0357.0239.0151.0-60.0288.0193.0102.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OperatingExpenses ▁▂▁▁▁▁▁▁▁▂▂▁▁▂▁▁▁▂▂▁▁▂▁▂▁▂▂▁▁▂▁▁▁▂█▂▂▄▂▃▂▃▂▄▂▃1186.01250.01117.01134.01044.01199.01137.01139.01099.01268.01253.01191.01178.01312.01177.01142.01140.01260.01211.01168.01102.01214.01168.01207.01164.01300.01245.01109.01097.01348.01151.01071.01142.01290.03325.01366.01297.02080.01430.01718.01465.01677.01508.02178.01394.01642.0NANANANA
us-gaap:OperatingIncomeLoss ▇▇▇▇▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▆█▇▇▇█▇▇▁█▇▅▆█▇▇▇▆▇▇▇▇▇▇286.0316.0211.0494.0354.0241.0179.0520.0280.0288.0166.0533.0385.0273.0225.0581.0398.0254.0145.0691.0325.0220.0140.0626.0237.0256.0125.0561.0322.0246.0171.0567.0261.0185.0-1816.0635.0363.0-422.0148.0550.0316.0227.0198.089.0331.0298.0245.0485.0365.0321.0
us-gaap:OtherIncome █▅▄▂█▃▁▃▂▃▄▃▃▂▁▁▂▁▅▂▂▂▁▁▁▄▃▃▄▃▂▂▁▁▁▂▁▂▂▁▁▃▁▂▄▂7.04.03.01.07.02.00.02.01.02.03.02.02.01.00.00.01.00.04.01.01.01.00.00.00.03.02.02.03.02.01.01.00.00.00.01.00.01.01.00.00.02.00.01.03.01.0NANANANA
us-gaap:OtherNonoperatingIncomeExpense ██▆██▄▅▆▆▅▃▅▅▄▂▂▂▂▂▂▂▃▂▃▂▂▃▃▃▂▂▃▂▂▂▂▃▁▂▃▂▂▂▃▄▃49.046.034.048.048.021.031.034.036.029.018.032.029.023.012.011.09.06.09.010.010.013.012.014.010.08.017.014.017.09.010.015.011.07.09.010.013.02.010.013.012.011.06.014.022.015.0NANANANA
 us-gaap:PreferredStockDividendsIncomeStatementImpact dei:LegalEntity aee:AmerenIllinoisCompany▁▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▁▄█0.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.00.01.02.0NANANANANA
 us-gaap:PreferredStockDividendsIncomeStatementImpact dei:LegalEntity aee:UnionElectricCompany▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▁▄▄▄▄▄█1.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.00.01.01.01.01.01.02.0NANANANANA
us-gaap:ProfitLoss ▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▆█▇▇▇█▇▇▆█▇▆▁█▇▄▆█▇▇▇▆▇▇208.0235.0116.0369.0244.0148.095.0366.0180.0193.069.0359.0240.0153.0-59.0290.0194.0104.033.0371.0148.0107.030.0345.0151.0110.049.0295.0150.098.038.0304.096.0-143.0-1155.0374.0210.0-403.026.0287.0139.074.054.0-164.0155.0106.0NANANANA
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax ▂▃▁▃▂▂▁▄▂▃▂▄▃▃▂▄▃▃▁▅▂▂▁▅▂▃▁▄▂▃▁▃▂▂▂▆▄▄▃█▄▅▄█▄▆▄▅▄▆1472.01566.01328.01628.01398.01440.01316.01659.01379.01556.01419.01724.01563.01585.01402.01723.01537.01514.01356.01859.01427.01434.01308.01833.01401.01556.01370.01670.01419.01594.01322.01638.01403.01475.01509.02001.01660.01658.01578.02268.01781.01904.01706.02267.01725.01940.01684.01824.01696.01931.0
us-gaap:Revenues ▂▃▁▃▂▂▁▃▂▃▂▄▃▃▂▄▃▃▁▅▂▂▁▅▂▃▁▄▂▃▁▃▂▂▂▆▄▄▃█▄▅▄█▄▆▄▅▄▆1472.01566.01328.01628.01398.01440.01316.01640.01379.01556.01419.01724.01563.01585.01402.01723.01538.01514.01356.01859.01427.01434.01308.01833.01401.01556.01370.01670.01419.01594.01322.01638.01403.01475.01509.02001.01660.01658.01578.02268.01781.01904.01706.02267.01725.01940.01684.01824.01696.01931.0
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:Assets █▇▇▆▆▅▅▅▅▅▄▄▄▄▄▃▃▃▃▃▂▂▂▂▂▂▂▁▁▁▁▂▂▁▁▂▂▂▂▂▂▂▂33916.032789.032030.030517.030016.029272.028933.028546.028103.027509.027215.026959.026639.026079.025945.025617.025254.024811.024699.024134.023793.023385.023640.023459.023152.022884.022676.021876.021588.021166.021042.022385.022276.021952.021835.023498.022980.022899.023645.023356.023391.023329.023515.0NANANA23702.0NANANA
 us-gaap:Liabilities us-gaap:ConsolidatedEntities srt:ParentCompanyNANA2265.0NANANA1500.0NANANA1360.0NANANA1264.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LiabilitiesAndStockholdersEquity █▇▇▆▆▅▅▅▅▅▄▄▄▄▄▃▃▃▃▃▂▂▂▂▂▂▂▁▁▁▁▂▂▁▁▂▂▂▂▂▂▂▂33916.032789.032030.030517.030016.029272.028933.028546.028103.027509.027215.026959.026639.026079.025945.025617.025254.024811.024699.024134.023793.023385.023640.023459.023152.022884.022676.021876.021588.021166.021042.022385.022276.021952.021835.023498.022980.022899.023645.023356.023391.023329.023515.0NANANA23702.0NANANA
us-gaap:StockholdersEquity ██▇▆▅▅▅▅▄▄▄▄▃▃▃▃▃▃▃▃▂▂▂▃▂▂▂▂▁▁▁▁▁▁▂▅▄▃▅9353.09148.08938.08489.08227.08085.08059.08062.07791.07705.07631.07656.07386.07230.07184.07345.07158.07064.07103.07193.06922.06869.06946.07014.06764.06704.06713.06774.06572.06513.06544.06574.06374.06365.06616.07874.07555.07432.07919.0NANA7725.07730.0NANANA7856.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:AssetsCurrent ▃▂▂▂▂▁▁▁▁▁▁▂▂▂▂▂▂▁▂▂▂▁▃▃▃▃▃▃▃▂▃███▄▄▄▃▄▅▅▆▆2116.01823.01653.01590.01620.01464.01431.01495.01514.01422.01533.01640.01685.01567.01612.01581.01571.01450.01593.01599.01594.01458.01917.01983.01991.01993.02046.01942.01965.01840.01972.03273.03408.03296.02369.02406.02154.02124.02295.02680.02603.02715.02894.0NANANA2842.0NANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▂▁▃▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▄▂▁▁▁▁▁▁▁▃▃▃▃▄▂▃▄▇▅▇▇█▇▅█99.06.0139.06.08.042.016.020.06.08.016.011.029.030.010.09.010.08.09.018.013.013.0292.072.02.06.05.013.046.026.030.0169.0150.0161.0209.0298.0117.0208.0255.0522.0378.0573.0545.0608.0506.0360.0622.0NANANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▇▄█▄▄▅▄▄▃▃▃▂▂▂▁▁▁267.0172.0301.0168.0163.0203.0176.0155.0122.0118.0107.092.096.089.068.057.053.0NA52.0NANANA351.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:AccountsReceivableNetCurrent ▁▃▂▅▄▃▁▄▃▅▃█▇▅▃▅▃▃▃▆▃▂▁▅▃▅▂▄▃▆▂▄▂▄▁▅▂▃▄▇▅▅▅397.0464.0415.0525.0486.0456.0393.0478.0461.0517.0463.0605.0560.0514.0445.0507.0446.0457.0437.0543.0445.0428.0388.0508.0456.0524.0423.0467.0454.0553.0404.0469.0425.0479.0401.0523.0417.0446.0473.0575.0507.0517.0500.0NANANA424.0NANANA
us-gaap:InventoryNet ▃▂▃▄▃▂▃▃▂▁▃▃▂▂▃▄▃▂▃▄▃▃▄▄▃▂▃▄▃▁▃▅▃▂▇█▇▅▇█▆▄▇527.0467.0521.0557.0514.0471.0494.0488.0433.0402.0483.0525.0475.0453.0522.0547.0512.0467.0527.0551.0515.0483.0538.0548.0500.0449.0524.0561.0491.0424.0526.0581.0511.0461.0704.0756.0686.0625.0712.0734.0654.0572.0707.0NANANA782.0NANANA
us-gaap:OtherAssetsCurrent ▆▄▄█▄▄▄▃▂▁▁▂▂▂▃▃▃▃▃▂▁▁▂▃▃▂▂▁▁▁▂▃▃▁▃▃▃▄▄▄▃▃▃165.0114.0135.0210.0131.0127.0118.0106.090.070.063.083.072.084.098.096.097.0105.098.076.068.063.088.0103.095.091.086.066.068.070.085.0108.0104.060.095.098.099.0134.0132.0132.0104.0100.0109.0NANANA98.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:PropertyPlantAndEquipmentGross NANA39719.0NANANA36652.0NANANA34002.0NANANA32027.0NANANA30118.0NANANA27603.0NANANA26198.0NANANA23701.0NANANA23909.0NANANA26468.0NANANA26154.0NANANA24475.0NANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity aee:AmerenIllinoisCompanyNANA14602.0NANANA13417.0NANANA12181.0NANANA11123.0NANANA10208.0NANANA9250.0NANANA8371.0NANANA6988.0NANANA6446.0NANANA6052.0NANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity aee:OtherAffiliatedEntitiesAndIntercompanyEliminationsNANA2019.0NANANA1878.0NANANA1615.0NANANA1409.0NANANA951.0NANANA387.0NANANA344.0NANANA336.0NANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity aee:UnionElectricCompanyNANA23098.0NANANA21357.0NANANA20206.0NANANA19495.0NANANA18959.0NANANA17966.0NANANA17483.0NANANA16377.0NANANA16031.0NANANA15484.0NANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:AmerenIllinoisCompany,aee:ElectricdistributionequipmentNANA6649.0NANANA6299.0NANANA5970.0NANANA5649.0NANANA5287.0NANANA4952.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:AmerenIllinoisCompany,aee:ElectrictransmissionequipmentNANA3575.0NANANA3101.0NANANA2647.0NANANA2298.0NANANA2016.0NANANA1674.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:AmerenIllinoisCompany,us-gaap:GasDistributionEquipmentNANA3308.0NANANA3024.0NANANA2701.0NANANA2419.0NANANA2186.0NANANA1997.0NANANA1854.0NANANA1562.0NANANA1461.0NANANA1368.0NANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:AmerenIllinoisCompany,us-gaap:PropertyPlantAndEquipmentOtherTypesNANA1070.0NANANA993.0NANANA863.0NANANA757.0NANANA719.0NANANA627.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:OtherAffiliatedEntitiesAndIntercompanyEliminations,aee:ElectrictransmissionequipmentNANA1774.0NANANA1642.0NANANA1385.0NANANA1167.0NANANA712.0NANANA121.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:OtherAffiliatedEntitiesAndIntercompanyEliminations,us-gaap:PropertyPlantAndEquipmentOtherTypesNANA245.0NANANA236.0NANANA230.0NANANA242.0NANANA239.0NANANA266.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,aee:CoalFiredElectricGenerationEquipmentNANA4875.0NANANA4730.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,aee:ElectricdistributionequipmentNANA6784.0NANANA6371.0NANANA5989.0NANANA5766.0NANANA5563.0NANANA5303.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,aee:ElectrictransmissionequipmentNANA1482.0NANANA1405.0NANANA1277.0NANANA1201.0NANANA1151.0NANANA979.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,aee:NaturalGasAndOilFiredElectricGenerationEquipmentNANA1097.0NANANA1090.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,aee:NuclearPoweredElectricGenerationEquipmentNANA5608.0NANANA5414.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,aee:RenewableElectricGenerationEquipmentNANA1301.0NANANA646.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,us-gaap:GasDistributionEquipmentNANA561.0NANANA528.0NANANA500.0NANANA474.0NANANA455.0NANANA445.0NANANA431.0NANANA413.0NANANA393.0NANANA385.0NANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity,us-gaap:PropertyPlantAndEquipmentByType aee:UnionElectricCompany,us-gaap:PropertyPlantAndEquipmentOtherTypesNANA1390.0NANANA1173.0NANANA1008.0NANANA922.0NANANA879.0NANANA808.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType aee:CoalFiredElectricGenerationEquipmentNANA4875.0NANANA4730.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType aee:ElectricdistributionequipmentNANA13433.0NANANA12670.0NANANA11959.0NANANA11415.0NANANA10850.0NANANA10255.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType aee:ElectrictransmissionequipmentNANA6831.0NANANA6148.0NANANA5309.0NANANA4666.0NANANA3879.0NANANA2774.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType aee:NaturalGasAndOilFiredElectricGenerationEquipmentNANA1097.0NANANA1090.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType aee:NuclearPoweredElectricGenerationEquipmentNANA5608.0NANANA5414.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType aee:RenewableElectricGenerationEquipmentNANA1301.0NANANA646.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:GasDistributionEquipmentNANA3869.0NANANA3552.0NANANA3201.0NANANA2893.0NANANA2641.0NANANA2442.0NANANA2285.0NANANA1975.0NANANA1854.0NANANA1746.0NANANA1661.0NANANA1583.0NANANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:PropertyPlantAndEquipmentOtherTypesNANA2705.0NANANA2402.0NANANA2101.0NANANA1921.0NANANA1837.0NANANA1701.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment NANA13773.0NANANA13006.0NANANA12273.0NANANA11633.0NANANA10961.0NANANA10347.0NANANA9759.0NANANA8644.0NANANA8823.0NANANA9429.0NANANA9194.0NANANA8787.0NANANA
 us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity aee:AmerenIllinoisCompanyNANA3780.0NANANA3536.0NANANA3294.0NANANA3082.0NANANA2850.0NANANA2632.0NANANA2422.0NANANA1627.0NANANA1495.0NANANA1364.0NANANANANANANANANANANA
 us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity aee:OtherAffiliatedEntitiesAndIntercompanyEliminationsNANA304.0NANANA275.0NANANA253.0NANANA246.0NANANA231.0NANANA255.0NANANA251.0NANANA251.0NANANANANANANANANANANANANANANANANANANA
 us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity aee:UnionElectricCompanyNANA9689.0NANANA9195.0NANANA8726.0NANANA8305.0NANANA7880.0NANANA7460.0NANANA7086.0NANANA6766.0NANANA6614.0NANANA6276.0NANANANANANANANANANANA
us-gaap:PropertyPlantAndEquipmentNet ██▇▇▆▆▆▆▅▅▅▅▅▄▄▄▄▄▄▃▃▃▃▃▂▂▂▂▂▂▁▁▁▁▁▂▂▂▃▂▂▂▂28020.027307.026807.025541.025081.024678.024376.023894.023479.023044.022810.022379.021998.021666.021466.020906.020589.020298.020113.019647.019324.019000.018799.018307.017986.017700.017424.016991.016726.016425.016205.015834.015601.015408.016096.017833.017690.017535.018127.017873.017945.017888.017853.0NANANA17610.0NANANA
us-gaap:Goodwill ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0411.0NANANA831.0NANANA
us-gaap:OtherAssetsNoncurrent ▇▇█▇▆▆▅▄▄▄▃▃▂▁▁▁▁▁▁▂▁▂▂▃▃▃▃▄▄▃▃▃▃▃▄▄▄▄▅▅▅▄▄1027.0989.01077.0993.0917.0885.0876.0780.0741.0744.0650.0647.0626.0532.0522.0538.0526.0532.0538.0566.0552.0573.0575.0646.0649.0645.0664.0724.0731.0719.0698.0660.0654.0665.0749.0772.0776.0773.0845.0843.0848.0738.0754.0NANANA655.0NANANA
 us-gaap:EquitySecuritiesFvNi dei:LegalEntity,us-gaap:FinancialInstrument aee:UnionElectricCompany,us-gaap:EquitySecuritiesNANA680.0NANANA569.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent ▆▄█▄▄▃▇▄▄▃▆▄▄▃▇▃▃▂▆▃▃▂▆▃▃▂▅▂▄▃▆▂▂▁▄▂▃▁▅▂▃▂▅779.0581.0958.0640.0616.0544.0874.0598.0593.0522.0817.0591.0565.0497.0902.0548.0522.0460.0805.0513.0499.0429.0777.0525.0486.0434.0711.0466.0575.0559.0806.0414.0428.0341.0625.0458.0479.0366.0693.0410.0482.0401.0651.0NANANA694.0NANANA
us-gaap:ContractWithCustomerLiabilityCurrent NANANA109.0126.0NA111.0NANA111.0116.0126.0NANA108.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:ContractWithCustomerLiabilityCurrent dei:LegalEntity aee:AmerenIllinoisCompany▁▁▂▄█▄▃▂▂▂▃▅69.070.074.080.094.080.077.071.071.073.076.084.0NANA69.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LiabilitiesCurrent ▃▄▃▃▃▄▅▄▆▄▅▅▆█▆▅▆▆▅▄▄▂▃▅▅▅▄▃▄▆▅██▅▂▁▁▁▂▂▂▂▂2177.02307.02180.02105.02000.02367.02505.02285.02752.02392.02687.02580.02711.03345.02940.02581.02765.02762.02674.02291.02430.01839.02093.02489.02556.02520.02249.02119.02312.02725.02461.03228.03286.02577.01698.01546.01603.01614.01785.01848.01727.01837.01888.0NANANA1711.0NANANA
us-gaap:LongTermDebtCurrent ▁▁▁▃▃▃▄▃▃▃▄▅▆█▆▆▄▅▅▄▄▂▃▃▃▃▂▂▂▅▄▆▆▃▃▂▂▂▂▂▁▂▂8.08.08.0357.0357.0357.0442.0336.0336.0336.0580.0649.0847.01170.0841.0777.0578.0681.0681.0431.0431.0135.0395.0395.0395.0380.0120.0119.0119.0648.0534.0884.0884.0355.0355.0206.0179.0179.0179.0178.05.0155.0155.0NANANA204.0NANANA
us-gaap:OtherLiabilitiesCurrent ▄▄▆▅▄█▇▆█▃▃▃▃▃▃▃▃▃▂▂▂▃▄▄▄▅▅▄▄▄▁▁▁▁▁▁▂▂▂▂▂▃▃414.0392.0489.0432.0374.0662.0585.0522.0668.0301.0282.0317.0298.0285.0326.0318.0298.0280.0248.0252.0270.0305.0379.0404.0413.0437.0434.0350.0350.0344.0194.0190.0178.0163.0188.0193.0221.0237.0207.0251.0262.0294.0283.0NANANA337.0NANANA
us-gaap:TaxesPayableCurrent ▇▄▁█▅178.0128.082.0199.0142.0NA37.0164.0NA81.053.0154.0139.091.052.0159.0122.077.046.0159.0124.077.043.0160.0126.079.046.0161.0132.089.055.0159.0123.091.068.0163.0141.0101.065.0161.0139.0134.063.0NANANA54.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:LongTermDebt NANA11190.0NANANA9442.0NANANA8509.0NANANA7995.0NANANA7326.0NANANA7331.0NANANA6251.0NANANA6048.0NANANA6992.0NANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt dei:LegalEntity aee:AmerenIllinoisCompanyNANA3988.0NANANA3613.0NANANA3330.0NANANA2857.0NANANA2607.0NANANA2496.0NANANA2246.0NANANA1859.0NANANA1729.0NANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt dei:LegalEntity aee:AmerenparentDomainNANA1600.0NANANA1150.0NANANA700.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt dei:LegalEntity aee:UnionElectricCompanyNANA5152.0NANANA4229.0NANANA4029.0NANANA3988.0NANANA4019.0NANANA4135.0NANANA4005.0NANANA3764.0NANANA4013.0NANANANANANANANANANANANANANANA
us-gaap:LongTermDebtNoncurrent █▇▇▆▆▅▅▄▄▄▄▃▃▂▃▃▃▂▂▂▂▃▃▂▂▂▂▂▂▁▁▁▁▂▂▂▂▂▂▂▃▃▃12492.011527.011078.010172.010171.09378.08915.08651.08222.08221.07859.07614.07613.06766.07094.06922.06821.06597.06595.06607.06605.06881.06880.05981.05981.05860.06120.05825.05825.05226.05504.05274.05274.05803.06626.06781.06678.06677.06677.06682.06854.06853.06853.0NANANA7111.0NANANA
 us-gaap:LongTermDebtAndCapitalLeaseObligations dei:LegalEntity,us-gaap:FairValueByMeasurementBasis aee:AmerenIllinoisCompany,us-gaap:CarryingReportedAmountFairValueDisclosure█▇▇▆▆▆▆▅▅▅▅▅▅▄▄▃▃▃▃▃▃▃▃▂▂▂▂▂▂▁▁4391.03947.03946.03576.03576.03575.03575.03279.03296.03296.03296.03114.03113.02830.02830.02590.02589.02588.02588.02344.02343.02472.02471.02241.02241.02241.02241.01940.01940.01692.01856.0NANANA1727.0NANANANANANANANANANANANANANANA
 us-gaap:LongTermDebtAndCapitalLeaseObligations dei:LegalEntity,us-gaap:FairValueByMeasurementBasis aee:UnionElectricCompany,us-gaap:CarryingReportedAmountFairValueDisclosure█▆▆▄▄▄▃▂▂▂▂▂▃▂▂▂▂▂▂▂▂▁▂▂▂▂▂▂▂▁▁5626.05104.05104.04568.04567.04567.04190.04115.04116.04116.03998.04004.04202.03962.03961.03967.03966.03995.03994.04000.03999.03851.04110.04135.04135.03999.03999.04004.04004.03758.03757.0NANANA4006.0NANANANANANANANANANANANANANANA
 us-gaap:LongTermDebtAndCapitalLeaseObligations us-gaap:FairValueByMeasurementBasis us-gaap:CarryingReportedAmountFairValueDisclosure█▇▇▆▆▅▅▄▄▄▄▄▄▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁12500.011535.011086.010529.010528.09735.09357.08987.08558.08557.08439.08263.08460.07936.07935.07699.07399.07278.07276.07038.07036.07016.07275.06376.06376.06240.06240.05944.05944.05874.06038.0NANANA6157.0NANANANANANANANANANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ▁▁▁▃▃▃▃▄▄▄▄▄▄▄▄▅▅▅▅▃▄▄▄▄▄▅▅▃▃▃▃▆▇▇▇▇▇██▆▆▆▆39.038.037.0373.0414.0397.0401.0522.0539.0558.0558.0529.0545.0541.0545.0711.0758.0768.0769.0499.0537.0581.0580.0666.0689.0708.0705.0400.0463.0480.0466.01042.01140.01113.01178.01152.01251.01357.01344.0922.01067.01057.01045.0NANANA1165.0NANANA
us-gaap:MinorityInterest ▁▁▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▃▃▃▃▃▃▃███129.0129.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0151.0151.0151.0151.0152.0145.0147.0149.0155.0155.0155.0154.0155.0206.0206.0204.0NANANA
us-gaap:OtherLiabilitiesNoncurrent ▂▂▃▂▂▃▃▃▃▁▁▁▂▂▂▃▃▃▃▃▃▄▄▄▄▄▄▄▄▅▇▄▆▆█▅▅▅▂▃▃▅▇447.0452.0466.0438.0456.0482.0467.0466.0464.0422.0408.0409.0431.0445.0460.0469.0477.0481.0477.0481.0490.0530.0531.0530.0524.0524.0514.0522.0524.0554.0622.0534.0585.0593.0668.0563.0564.0567.0447.0469.0481.0553.0615.0NANANA491.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:StockholdersEquity ██▇▆▅▅▅▅▄▄▄▄▃▃▃▃▃▃▃▃▂▂▂▃▂▂▂▂▁▁▁▁▁▁▂▅▄▃▅9353.09148.08938.08489.08227.08085.08059.08062.07791.07705.07631.07656.07386.07230.07184.07345.07158.07064.07103.07193.06922.06869.06946.07014.06764.06704.06713.06774.06572.06513.06544.06574.06374.06365.06616.07874.07555.07432.07919.0NANA7725.07730.0NANANA7856.0NANANA
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest ██▇▆▅▅▅▅▄▄▄▄▃▃▃▃▃▃▃▃▂▂▂▃▂▂▂▂▁▁▁▁▁▁▂▅▄▄▅▅▄▄▄9482.09277.09080.08631.08369.08227.08201.08204.07933.07847.07773.07798.07528.07372.07326.07487.07300.07206.07245.07335.07064.07011.07088.07156.06906.06846.06855.06916.06714.06655.06686.06725.06525.06516.06767.08026.07700.07579.08068.08152.07943.07880.07884.0NANANA8060.0NANANA
us-gaap:CommonStockValue ███▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁3.03.03.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.0NANANA2.0NANANA
us-gaap:AdditionalPaidInCapital █▇▆▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁6436.06295.06179.05733.05716.05695.05694.05673.05649.05625.05627.05598.05576.05546.05540.05534.05528.05522.05556.05550.05545.05539.05616.05612.05606.05600.05617.05612.05607.05602.05632.05624.05619.05614.05616.05611.05600.05596.05598.05580.05559.05540.05520.0NANANA5412.0NANANA
us-gaap:RetainedEarningsAccumulatedDeficit ██▇█▇▆▆▆▆▅▅▅▄▄▄▄▄▄▄▄▃▃▃▃▂▂▂▂▂▁▁▂▁▁▂▆▅▅▆▆▆▆▆2915.02850.02757.02769.02525.02404.02380.02408.02161.02099.02024.02073.01827.01699.01660.01830.01649.01563.01568.01643.01376.01333.01331.01405.01161.01111.01103.01154.0957.0906.0907.0967.0762.0764.01006.02259.01983.01869.02369.02440.02248.02203.02225.0NANANA2455.0NANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax -1.0NA-1.0-15.0-16.0-16.0-17.0-21.0-21.0-21.0-22.0-17.0-19.0-17.0-18.0-21.0-21.0-23.0-23.0-2.0-1.0-5.0-3.0-5.0-5.0-9.0-9.06.06.03.03.0-19.0-9.0-15.0-8.02.0-30.0-35.0-50.0-25.0-21.0-20.0-17.0NANANA-13.0NANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities srt:ParentCompanyNANA-1.0NANANA-17.0NANANA-22.0NANANA-18.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:MinorityInterest ▁▁▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▃▃▃▃▃▂▃▃▃▃▃▃▃███129.0129.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0142.0151.0151.0151.0151.0152.0145.0147.0149.0155.0155.0155.0154.0155.0206.0206.0204.0NANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital█▁▁▁▁▁▁▁▂▂▂▁▂▁121.012.014.010.014.013.014.017.018.019.018.016.023.017.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital▇▄▇▇▇▃▇▇▇▁█▇▇▃8.0-9.08.07.07.0-12.07.07.06.0-21.011.06.07.0-11.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:StatementEquityComponents us-gaap:NoncontrollingInterest▁█▁█▁█▁█▁█▁█▁█1.02.01.02.01.02.01.02.01.02.01.02.01.02.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▅▁▄▆▄▄▅▇▅▄▅█▆▃▅▇▅▄▆▇▄▄▅▇▅▄▄▆▄▃▄▆▄▄▄▆▄▄▄▆▄▆▄▇▄▄471.0-35.0398.0635.0404.0290.0502.0789.0492.0387.0484.0866.0562.0258.0461.0780.0532.0331.0564.0796.0414.0349.0489.0761.0469.0298.0348.0549.0415.0239.0379.0546.0389.0379.0329.0556.0413.0392.0312.0663.0349.0554.0346.0725.0391.0380.0NANANANA
us-gaap:NetCashProvidedByUsedInInvestingActivities ▄▄▁▅▅▅▅▅▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▇▇▆▇▇▇▅▇▇▇▇▇▇▇████▇██▇-871.0-889.0-1348.0-666.0-631.0-684.0-637.0-644.0-587.0-567.0-617.0-590.0-532.0-597.0-620.0-526.0-520.0-539.0-590.0-516.0-525.0-510.0-614.0-487.0-436.0-439.0-505.0-442.0-457.0-313.0-690.0-396.0-334.0-303.0-299.0-373.0-312.0-326.0-291.0-259.0-248.0-250.0-336.0-216.0-243.0-317.0NANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity aee:AmerenIllinoisCompany▂▂▁▂▂▃▃▂▃▄▃▂▃▃▃▃▄▄▄▄▅▄▃▄▅▅▅▅▄▅▄▅▆▆▆▇▅▇▇▇▆█▇▇-331.0-337.0-414.0-371.0-336.0-323.0-302.0-345.0-291.0-267.0-311.0-338.0-299.0-300.0-316.0-274.0-253.0-227.0-239.0-241.0-169.0-269.0-298.0-240.0-168.0-207.0-201.0-195.0-218.0-214.0-239.0-177.0-141.0-138.0-133.0-57.0-161.0-86.0-84.0-87.0-106.0-19.0-64.0-72.0NANANANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity aee:UnionElectricCompany▃▅▁▆▆▆▆▆▆▆▆▇▆▆▆▇▇▇▆▅▇▇█▅▇▇▆▇▆▇▇▆▇▇▇▇▇▆▇▇▇▇▆▇-655.0-398.0-1027.0-273.0-276.0-328.0-310.0-264.0-257.0-264.0-241.0-192.0-278.0-265.0-230.0-202.0-185.0-68.0-210.0-370.0-184.0-170.015.0-411.0-159.0-169.0-244.0-180.0-209.0-204.0-181.0-221.0-156.0-129.0-133.0-177.0-175.0-218.0-168.0-139.0-164.0-156.0-219.0-130.0NANANANANANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅▇█▃▄▅▄▂▃▄▄▂▃▅▄▂▃▄▃▂▃▂▅▂▃▄▄▂▃▃▄▂▃▂▂▃▂▂▂▂▂▂▃▁▃▁495.0795.01083.036.0187.0421.0156.0-112.099.0191.0148.0-280.0-23.0360.0160.0-255.0-10.0207.017.0-275.0111.0-118.0345.0-204.0-37.0142.0149.0-140.062.070.0147.0-131.0-66.0-99.0-119.0-2.0-192.0-113.0-288.0-260.0-296.0-276.0-73.0-407.0-2.0-325.0NANANANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect █▁95.0-129.0NA5.0-40.027.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:IncreaseDecreaseInInventories ▇▄▄▇▇▅▆▇▆▃▄▇▆▃▄▆▇▄▅▆▆▄▅▇▇▃▄▇▇▂▄▇▇▂▄▇▇▃▅██▁▄▇▇▁59.0-54.0-36.042.042.0-23.06.054.031.0-81.0-43.050.022.0-68.0-37.034.046.0-60.0-24.036.032.0-55.0-9.048.050.0-75.0-37.069.067.0-102.0-53.070.050.0-127.0-49.071.053.0-80.0-7.089.080.0-135.0-39.069.040.0-148.0NANANANA
us-gaap:NetCashProvidedByUsedInOperatingActivities ▅▁▄▆▄▄▅▇▅▄▅█▆▃▅▇▅▄▆▇▄▄▅▇▅▄▄▆▄▃▄▆▄▄▄▆▄▄▄▆▄▆▄▇▄▄471.0-35.0398.0635.0404.0290.0502.0789.0492.0387.0484.0866.0562.0258.0461.0780.0532.0331.0564.0796.0414.0349.0489.0761.0469.0298.0348.0549.0415.0239.0379.0546.0389.0379.0329.0556.0413.0392.0312.0663.0349.0554.0346.0725.0391.0380.0NANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity aee:AmerenIllinoisCompany▅█▅▄▅▇▅▄▄▇▅▄▄▅▄▃▃▄▂▆▃▃▂▅▂▃▃▄▂▃▂▄▂▂▁▄▂▂▂▅▂▂86.0149.099.077.083.0120.096.065.062.0120.084.063.062.095.077.055.057.079.027.0119.046.060.033.098.032.054.046.075.029.054.022.077.032.032.012.071.033.028.026.098.038.034.0NANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity aee:UnionElectricCompany▄▃▂█▅▂▁█▄▃▁█▅▃▁▇▄▂▂▇▄▂▂▇▃▃▂▆▄▃▂▇▄▃▂▇▅▂▁▆▄▂111.047.0-3.0297.0152.0-10.0-20.0300.0107.039.0-22.0294.0168.038.0-36.0234.0120.05.07.0242.093.015.011.0240.062.042.0-5.0223.0127.048.033.0239.085.041.016.0237.0144.022.0-14.0191.091.022.0NANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionNANA36.034.036.037.041.032.037.036.035.035.033.033.037.031.033.030.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionSegment▁█41.046.0NANA36.037.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisGasNANA33.02.09.055.027.0-1.01.057.021.00.07.042.020.02.05.033.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisGasSegment▁█8.075.0NANA9.055.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisTransmissionNANA30.041.038.028.028.034.024.027.028.028.022.020.020.022.019.016.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments aee:AmerenIllinoisCompany,us-gaap:OperatingSegments,aee:AmerenIllinoisTransmissionSegment█▁37.028.0NANA38.028.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionNANA36.034.036.037.041.032.037.036.035.035.033.033.037.031.033.030.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisElectricDistributionSegment▁█41.046.0NANA36.037.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisGasNANA33.02.09.055.027.0-1.01.057.021.00.07.042.020.02.05.033.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenIllinoisGasSegment▁█8.075.0NANA9.055.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenTransmissionNANA48.062.059.047.046.053.042.044.043.048.036.037.034.038.034.034.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:AmerenTransmissionSegment█▁55.047.0NANA59.047.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:OtherSegmentNANA1.0-28.0-13.017.00.0-20.0-8.015.0-9.0-20.0-5.01.0-115.0-17.01.00.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,aee:UnionElectricCompany▄▃▂█▅▂▁█▄▃▁█▅▃▁▇111.047.0-3.0297.0152.0-10.0-20.0300.0107.039.0-22.0294.0168.038.0-36.0234.0NA5.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:ProfitLoss ▇▇▇█▇▇▇█▇▇▇█▇▇▆█▇▇▆█▇▇▆█▇▇▇█▇▇▆█▇▆▁█▇▄▆█▇▇▇▆▇▇208.0235.0116.0369.0244.0148.095.0366.0180.0193.069.0359.0240.0153.0-59.0290.0194.0104.033.0371.0148.0107.030.0345.0151.0110.049.0295.0150.098.038.0304.096.0-143.0-1155.0374.0210.0-403.026.0287.0139.074.054.0-164.0155.0106.0NANANANA
us-gaap:ShareBasedCompensation ▄▅▄▄▄▅▄▄▄▅▄▄▄▅▄▄▄▄▁▄▅▅▄▅▅▆▄▄▅▇▆▄▄▇▅█▄▆5.06.05.05.05.06.05.05.04.06.05.05.04.06.05.04.04.04.00.05.06.06.04.06.06.08.05.05.06.09.08.05.05.09.06.011.04.08.0NANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▄▄▁▅▅▅▅▅▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▇▇▆▇▇▇▅▇▇▇▇▇▇▇████▇██▇-871.0-889.0-1348.0-666.0-631.0-684.0-637.0-644.0-587.0-567.0-617.0-590.0-532.0-597.0-620.0-526.0-520.0-539.0-590.0-516.0-525.0-510.0-614.0-487.0-436.0-439.0-505.0-442.0-457.0-313.0-690.0-396.0-334.0-303.0-299.0-373.0-312.0-326.0-291.0-259.0-248.0-250.0-336.0-216.0-243.0-317.0NANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity aee:AmerenIllinoisCompany▂▂▁▂▂▃▃▂▃▄▃▂▃▃▃▃▄▄▄▄▅▄▃▄▅▅▅▅▄▅▄▅▆▆▆▇▅▇▇▇▆█▇▇-331.0-337.0-414.0-371.0-336.0-323.0-302.0-345.0-291.0-267.0-311.0-338.0-299.0-300.0-316.0-274.0-253.0-227.0-239.0-241.0-169.0-269.0-298.0-240.0-168.0-207.0-201.0-195.0-218.0-214.0-239.0-177.0-141.0-138.0-133.0-57.0-161.0-86.0-84.0-87.0-106.0-19.0-64.0-72.0NANANANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity aee:UnionElectricCompany▃▅▁▆▆▆▆▆▆▆▆▇▆▆▆▇▇▇▆▅▇▇█▅▇▇▆▇▆▇▇▆▇▇▇▇▇▆▇▇▇▇▆▇-655.0-398.0-1027.0-273.0-276.0-328.0-310.0-264.0-257.0-264.0-241.0-192.0-278.0-265.0-230.0-202.0-185.0-68.0-210.0-370.0-184.0-170.015.0-411.0-159.0-169.0-244.0-180.0-209.0-204.0-181.0-221.0-156.0-129.0-133.0-177.0-175.0-218.0-168.0-139.0-164.0-156.0-219.0-130.0NANANANANANA
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▆▇█▆▆▆▆▆▆▅▆▅▅▅▆▅▄▅▆▄▅▄▆▄▄▄▄▄▄▄▄▃▂▂▃▃▂▂▂▁▂▁▂▁▂▂652.0694.0785.0656.0592.0636.0650.0636.0581.0544.0597.0577.0533.0579.0609.0525.0494.0504.0580.0496.0504.0496.0585.0486.0429.0417.0475.0427.0441.0442.0436.0368.0300.0275.0335.0340.0283.0282.0272.0251.0280.0227.0274.0210.0258.0289.0NANANANA
us-gaap:PaymentsToAcquireProductiveAssets ▁█876.0887.0NANA592.0636.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅▇█▃▄▅▄▂▃▄▄▂▃▅▄▂▃▄▃▂▃▂▅▂▃▄▄▂▃▃▄▂▃▂▂▃▂▂▂▂▂▂▃▁▃▁495.0795.01083.036.0187.0421.0156.0-112.099.0191.0148.0-280.0-23.0360.0160.0-255.0-10.0207.017.0-275.0111.0-118.0345.0-204.0-37.0142.0149.0-140.062.070.0147.0-131.0-66.0-99.0-119.0-2.0-192.0-113.0-288.0-260.0-296.0-276.0-73.0-407.0-2.0-325.0NANANANA
us-gaap:ProceedsFromIssuanceOfLongTermDebt █▄█▁▇▄▆▄▁▄▅▁▇▁▅▃973.0450.0920.00.0798.0465.0627.0450.00.0450.0499.00.0853.00.0496.0300.0NANA240.00.0NANA948.00.0NANA300.00.0NANANANANANA0.0NANANANANANANANANANANANANANANA
us-gaap:RepaymentsOfLongTermDebt NANANA0.00.085.0NA0.00.0329.0NA199.0323.00.0NA0.0425.00.0NA0.0129.0260.0NA0.0114.00.0NA0.0529.0163.0NANANANANANANANANA0.0NANANANANANANANANANA
 us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity aee:UnionElectricCompanyNANANA0.00.085.0NA0.00.0329.0NA199.0179.00.0NA0.0425.00.0NA0.00.0260.0NA0.0114.00.0NA0.0NANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PaymentsOfDividendsCommonStock ██▆▅▅▅▅▅▅▄▅▄▄▄▄▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▂▁▁▁▁▁▁▁142.0140.0127.0123.0122.0122.0122.0117.0117.0116.0117.0111.0112.0111.0111.0106.0107.0107.0107.0103.0103.0103.0104.099.0100.099.099.097.097.097.097.097.097.097.098.097.097.090.096.093.093.093.092.093.092.091.0NANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3.03.03.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-31
Value3.02.0
Percentage of CommonStockValue100.0100.0
Percentage of Assets0.00.0
Percentage of Assets srt:ParentCompany0.00.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding

us-gaap:CommonStockSharesOutstanding


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value257255253247247246246246245245244244243243242242242242242242242242242242242242242242242242242242242242242242242242242242241241240237212
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockSharesOutstanding us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-312018-12-312017-12-31
Value253246244242
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302016-09-302015-09-302014-09-302013-09-302012-09-30
Value257255249247248247247246246245244244243242243244245242
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value256254247246246245245244244243242242242242242242242242242242242242242242242242242246242241241240239238237
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value0.810.920.471.480.990.590.381.480.730.780.281.460.980.62-0.241.190.790.420.131.520.610.430.121.420.610.450.21.210.610.40.151.250.39-0.6-4.761.540.87-1.66
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value0.80.910.461.470.980.590.381.470.720.780.281.450.970.62-0.241.180.790.420.131.520.610.430.121.410.610.450.21.20.610.40.151.240.39-0.6-4.761.540.87-1.66
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value2062341293682431479836417919263359237152-57.02881951021136815110331343154108332931529659292101-152.0-1166.0406216-388.00.028113768
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.014.90.022.617.410.27.421.913.012.34.420.815.29.6-4.116.712.76.70.819.810.67.22.418.711.06.92.417.510.76.04.517.87.2-10.3-77.320.313.0-23.40.012.47.73.6

Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312012-12-312012-09-302012-06-302011-12-312011-09-302011-06-30
Value1.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.00.09.0-1.0-5.02.01.0
Percentage of ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.00.4-0.1-0.30.10.1

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2072361303702441499936618019464361238154-56.029019610412370152105-1166.0415215-388.0-5.02831387145-164.0146118
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.115.10.022.717.510.37.522.113.112.54.520.915.29.7-4.016.812.86.90.919.910.77.3-77.320.713.0-23.4-0.312.57.73.72.6-7.28.56.1

Gain Loss On Investments

us-gaap:GainLossOnInvestments

us-gaap:GainLossOnInvestments


Gain
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value632247107-111.010.02664
Percentage of GainLossOnInvestments100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.31.42.97.7-7.70.61.94.1

us-gaap:GainLossOnInvestments dei:LegalEntity

aee:UnionElectricCompany


Gain
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value632247107-111.010.02664
Percentage of GainLossOnInvestments100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.31.42.97.7-7.70.61.94.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany7.83.14.713.5-16.30.93.38.4

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
Value239262137432294169119458219220854643141951414953081615960424013861553158176674902501637249417291-1917.0532264-533.04345022411984-27.0238181
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 RevenueFromContractWithCustomerIncludingAssessedTax16.216.70.026.521.011.79.027.615.914.16.026.920.112.310.128.720.010.64.432.516.89.64.730.211.311.34.929.317.610.25.430.212.36.2-127.026.615.9-32.12.719.812.66.24.9-1.213.89.3

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments dei:LegalEntity

aee:AmerenIllinoisCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1172001311021131601288583160110868112811793951324419675984615752897912950893912854522011755464216364546514579
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments49.076.395.623.638.494.7107.618.637.972.7129.418.525.865.683.018.830.882.074.632.531.271.075.428.432.950.6117.926.320.054.654.225.931.457.1-1.022.020.8-8.697.736.228.645.477.4-537.033.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.912.80.06.38.111.19.75.16.010.37.85.05.28.18.35.46.28.73.210.55.36.83.58.63.75.75.87.73.55.63.07.83.83.51.35.83.32.82.77.23.62.83.86.44.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany18.624.30.017.319.922.119.615.115.221.016.315.214.016.817.416.216.518.87.429.013.814.58.324.010.111.912.522.69.611.56.923.410.57.63.418.19.86.46.921.910.36.70.019.412.2

aee:UnionElectricCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value109462.0316165-10.0-22.035212344-30.0360223520.03781939.011390151241538010168-10.03522037758388134602538522734-19.0293144331.0344173
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments45.617.61.573.156.1-5.9-18.576.956.220.0-35.377.671.026.70.076.462.75.618.664.662.917.424.668.763.938.6-14.971.881.247.280.678.577.965.9-1.372.486.0-6.4-44.265.164.327.71.2-1274.172.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.42.90.019.411.8-0.7-1.721.28.92.8-2.120.914.33.30.021.912.60.60.821.010.61.71.120.77.24.4-0.721.114.34.84.423.79.64.11.719.213.72.1-1.212.98.11.70.115.210.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany13.56.50.031.620.8-1.5-3.533.215.45.8-4.231.923.46.60.033.920.71.11.533.517.43.22.032.511.48.5-1.432.122.69.47.635.515.17.53.736.226.94.9-2.826.317.54.30.032.522.7

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
Value3127216350212492392716105744220020511457262339231302085966201949964231876635-762.015854-130.0171638545301378375
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 RevenueFromContractWithCustomerIncludingAssessedTax2.11.70.03.93.61.51.85.52.81.71.16.14.72.614.311.97.43.81.912.56.42.22.311.34.24.21.511.67.04.01.711.44.72.4-50.57.93.3-7.81.17.24.82.41.86.04.83.9

us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity

aee:AmerenIllinoisCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value315031252939312020392523183239383752147729381359203533542135175122208.046221816652620285431
Percentage of IncomeTaxExpenseBenefit100.0185.2147.639.758.0185.7129.221.751.3144.4156.221.924.376.219.518.532.591.253.833.031.5122.643.328.433.953.0165.027.821.254.773.927.333.357.1-1.029.140.7-13.894.139.930.644.493.339.437.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.13.20.01.52.12.72.41.21.52.51.81.31.22.02.82.22.43.41.04.12.02.61.03.21.42.22.43.21.52.21.33.11.61.40.52.31.31.11.02.91.51.11.62.41.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany4.96.10.04.25.15.44.73.53.75.13.74.13.14.25.86.66.47.42.411.45.45.62.49.03.94.75.29.44.04.53.09.34.32.91.47.13.92.52.68.74.22.50.07.24.8

aee:UnionElectricCompany


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-3.0-2.05.01812-1.0-2.051154.0-8.065541336143723.01.0148589.04.01403926-5.012976292514949199.01488312-5.01025311-1.012058
Percentage of IncomeTaxExpenseBenefit-9.7-7.423.828.624.0-4.8-8.355.438.514.8-50.061.973.031.018.069.863.25.33.863.563.029.013.367.366.139.4-25.066.576.845.3108.779.774.254.3-1.293.7153.7-9.2-29.462.662.424.4-3.387.669.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.2-0.10.01.10.9-0.1-0.23.11.10.3-0.63.83.50.82.68.34.70.20.18.04.10.60.37.62.81.7-0.47.75.41.81.99.13.51.30.67.45.00.7-0.34.53.00.6-0.15.33.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany-0.4-0.30.01.81.5-0.1-0.34.81.90.5-1.15.85.71.65.212.87.70.40.112.76.71.20.512.04.43.2-0.711.88.43.53.313.65.52.41.313.99.81.7-0.79.16.41.40.011.37.6

us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility

aee:UnionElectricCompany, aee:FinalRateOrder, us-gaap:Electricity


Income
Period End2020-12-312020-09-302020-06-302020-03-31
Value0.00.00.020
Percentage of IncomeTaxExpenseBenefit0.00.00.095.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.01.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany aee:FinalRateOrder us-gaap:Electricity0.00.00.00.0

Interest Expense

us-gaap:InterestExpense

us-gaap:InterestExpense


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value961001081101089391969797991011001019697999995979595918789887585899210988100101110113112113115113104119120130115132
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.56.40.06.87.76.56.95.87.06.27.05.96.46.46.85.66.46.57.05.26.76.67.04.76.45.75.55.16.35.88.25.47.16.87.35.66.76.87.35.05.86.27.05.76.76.8

us-gaap:InterestExpense dei:LegalEntity

aee:AmerenIllinoisCompany


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
Value404239393839363836373738373735363637353535353233333322312930473134313134313333333535353734
Percentage of InterestExpense41.742.036.135.535.241.939.639.637.138.137.437.637.036.636.537.136.437.436.836.136.836.835.237.937.137.529.336.532.632.643.135.234.030.728.230.127.729.228.729.233.729.429.228.529.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.72.70.02.42.72.72.72.32.62.42.62.22.42.32.52.12.32.42.61.92.52.42.41.82.42.11.61.92.01.93.61.92.42.12.11.71.92.02.11.52.01.82.11.62.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany6.45.10.06.66.75.45.56.76.64.95.56.76.44.95.26.36.25.35.95.26.55.25.85.06.44.43.55.45.63.98.35.76.64.55.35.25.54.65.44.45.64.30.05.05.3

aee:UnionElectricCompany


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
Value363950505040424445474850515150505354535353525554555552535452514356605655565656544554555643
Percentage of InterestExpense37.539.046.345.546.343.046.245.846.448.548.549.551.050.552.151.553.554.555.854.655.854.760.462.161.862.569.362.460.756.546.848.956.059.450.948.750.049.648.747.843.345.445.843.137.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.42.50.03.13.62.83.22.73.33.03.42.93.33.23.62.93.43.63.92.93.73.64.22.93.93.53.83.23.83.33.92.64.04.13.72.73.43.43.52.42.52.83.22.52.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany4.45.50.05.06.35.96.74.25.66.26.74.45.36.47.24.55.76.87.14.56.17.07.34.66.26.97.04.86.06.46.73.96.37.58.35.26.68.18.34.85.57.00.05.35.7

Net Income Loss

us-gaap:NetIncomeLoss dei:LegalEntity

us-gaap:NetIncomeLoss

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value8614999778312096656212084636295775557792711946603398325446752954227732321271332826983834
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.50.04.75.98.37.33.94.57.75.93.74.06.05.53.23.75.22.06.43.24.22.55.32.33.53.44.52.03.41.74.72.32.20.83.52.01.71.64.32.11.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany13.718.10.013.114.616.614.711.511.315.712.511.210.712.511.49.69.911.24.517.68.58.96.015.06.27.27.313.15.67.03.914.16.24.72.011.05.93.94.313.26.14.2

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value11147-3.0297152-10.0-20.030010739-22.029416838-36.02341205.07.02429315112406242-5.0223127483323985411623714422-14.01919122
Percentage of NetIncomeLoss129.131.5-3.0385.7183.1-8.3-20.8461.5172.632.5-26.2466.7271.040.0-46.8425.5210.56.325.9203.4202.225.033.3244.9193.877.8-10.9297.3437.988.9150.0310.4265.6128.1133.3333.8436.478.6-53.8194.9239.564.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.53.00.018.210.9-0.7-1.518.17.82.5-1.617.110.72.4-2.613.67.80.30.513.06.51.00.813.14.42.7-0.413.48.93.02.514.66.12.81.111.88.71.3-0.98.45.11.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany13.76.70.029.719.2-1.5-3.228.313.45.1-3.126.017.64.8-5.221.012.80.60.920.810.72.01.520.57.05.2-0.720.314.15.94.321.99.65.22.422.317.13.2-2.117.111.12.8

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

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistribution


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value36343637413237363535333337313330
Percentage of NetIncomeLoss36.444.243.430.842.749.259.730.041.755.653.234.748.156.457.938.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.02.12.62.63.11.92.72.32.52.02.12.12.61.82.12.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value41463637
Percentage of NetIncomeLoss47.730.943.430.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.82.92.62.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistributionSegment10.611.210.29.5

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisGas


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value332.09.05527-1.01.057210.07.042202.05.033
Percentage of NetIncomeLoss33.32.610.845.828.1-1.51.647.525.00.011.344.226.03.68.841.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.10.63.82.1-0.10.13.71.50.00.42.61.40.10.32.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisGas0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value8.0759.055
Percentage of NetIncomeLoss9.350.310.845.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.54.80.63.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisGasSegment4.821.66.420.3

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisTransmission


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value30413828283424272828222020221916
Percentage of NetIncomeLoss30.353.245.823.329.252.338.722.533.344.435.521.126.040.033.320.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.02.52.71.92.12.01.71.72.01.61.41.31.41.31.21.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisTransmission0.00.00.00.00.00.00.00.00.039.435.50.00.030.629.20.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisTransmissionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value37283828
Percentage of NetIncomeLoss43.018.845.823.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.51.82.71.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisTransmissionSegment50.743.150.745.2

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value-8.018-13.017
Percentage of NetIncomeLoss-9.312.1-15.714.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.51.1-0.91.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MaterialReconcilingItems0.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistribution


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value36343637413237363535333337313330
Percentage of NetIncomeLoss36.444.243.430.842.749.259.730.041.755.653.234.748.156.457.938.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.02.12.62.63.11.92.72.32.52.02.12.12.61.82.12.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistribution0.08.710.29.50.08.210.39.30.08.98.58.20.07.78.57.8

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value41463637
Percentage of NetIncomeLoss47.730.943.430.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.82.92.62.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistributionSegment10.611.210.29.5

us-gaap:OperatingSegments, aee:AmerenIllinoisGas


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value332.09.05527-1.01.057210.07.042202.05.033
Percentage of NetIncomeLoss33.32.610.845.828.1-1.51.647.525.00.011.344.226.03.68.841.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.10.63.82.1-0.10.13.71.50.00.42.61.40.10.32.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisGas0.01.66.420.30.0-0.90.717.80.00.04.913.50.01.83.712.5

us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value8.0759.055
Percentage of NetIncomeLoss9.350.310.845.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.54.80.63.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisGasSegment4.821.66.420.3

us-gaap:OperatingSegments, aee:AmerenTransmission


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value48625947465342444348363734383434
Percentage of NetIncomeLoss48.580.571.139.247.981.567.736.751.276.258.138.944.269.159.643.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.03.84.23.33.53.23.02.83.02.82.32.32.42.22.22.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenTransmission0.044.043.438.20.041.438.538.60.042.535.035.60.031.932.40.0

us-gaap:OperatingSegments, aee:AmerenTransmissionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value55475947
Percentage of NetIncomeLoss64.031.571.139.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.73.04.23.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenTransmissionSegment46.241.647.642.7

us-gaap:OperatingSegments, aee:OtherSegment


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.0-28.0-13.0170.0-20.0-8.015-9.0-20.0-5.01.0-115.0-17.01.00.0
Percentage of NetIncomeLoss1.0-36.4-15.714.20.0-30.8-12.912.5-10.7-31.7-8.11.1-149.4-30.91.80.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-1.7-0.91.20.0-1.2-0.61.0-0.6-1.2-0.30.1-8.2-1.00.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:OtherSegment0.00.00.00.00.00.00.00.00.00.00.00.00.0850.050.00.0

us-gaap:OperatingSegments, aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-03-31
Value11147-3.0297152-10.0-20.030010739-22.029416838-36.02345.0
Percentage of NetIncomeLoss129.131.5-3.0385.7183.1-8.3-20.8461.5172.632.5-26.2466.7271.040.0-46.8425.56.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.53.00.018.210.9-0.7-1.518.17.82.5-1.617.110.72.4-2.613.60.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:UnionElectricCompany13.96.80.029.719.2-1.50.028.313.45.10.026.017.64.80.021.00.6

Net Income Loss Attributable To Noncontrolling Interest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312013-06-302013-03-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.01.02.00.0-1.02.01.02.01.03.02.03.03.04.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.0-0.10.10.10.10.10.20.10.10.20.2

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:NoncontrollingInterest


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-1.0-2.011-2.0-1.0-2.011-2.01.02.011-2.01.02.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest-100.0-100.01100.0-100.0-100.0-100.01100.0-100.0100.0100.01100.0-100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.1-0.10.0-0.1-0.1-0.10.8-0.10.10.10.8-0.10.10.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2072331153672431469436417919168357239151-60.0288193102
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.114.90.022.517.410.17.121.913.012.34.820.715.39.5-4.316.712.66.7

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value2072331153672431469436417919168357239151
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.114.90.022.517.410.17.121.913.012.34.820.715.39.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Expenses

us-gaap:OperatingExpenses

us-gaap:OperatingExpenses


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1186125011171134104411991137113910991268125311911178131211771142114012601211116811021214116812071164130012451109109713481151107111421290332513661297208014301718146516771508217813941642
Percentage of OperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax80.679.80.069.774.783.386.468.779.781.588.369.175.482.884.066.374.283.289.362.877.284.789.365.883.183.590.966.477.384.687.165.481.487.5220.368.378.1125.590.675.782.388.188.496.180.884.6

us-gaap:OperatingExpenses dei:LegalEntity

aee:AmerenIllinoisCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value488595500465433535504454443576539451473601524447446531521446435544479466430625536414444654479389429599538497478635536549524720604564535
Percentage of OperatingExpenses41.147.644.841.041.544.644.339.940.345.443.037.940.245.844.539.139.142.143.038.239.544.841.038.636.948.143.137.340.548.541.636.337.646.416.236.436.930.537.532.035.842.940.125.938.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax33.238.00.028.631.037.238.327.432.137.038.026.230.337.937.425.929.035.138.424.030.537.936.625.430.740.239.124.831.341.036.223.730.640.635.724.828.838.334.024.229.437.835.424.931.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany77.672.30.078.976.474.077.180.581.075.680.080.081.879.177.777.977.475.587.666.080.380.486.671.183.883.984.772.485.584.584.971.183.187.691.376.784.887.787.773.784.189.10.075.682.7

aee:UnionElectricCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value688642605661602654623678646679706735697702659698698737696734670678696748738685710703657698667676710685604635575613651782646695655675564
Percentage of OperatingExpenses58.051.454.258.357.754.554.859.558.853.556.361.759.253.556.061.161.258.557.562.860.855.859.662.063.452.757.063.459.951.857.963.162.253.118.246.544.329.545.545.544.141.443.431.040.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax46.741.00.040.643.145.447.340.946.843.649.842.644.644.347.040.545.448.751.339.547.047.353.240.852.744.051.842.146.343.850.541.350.646.440.031.734.637.041.334.536.336.538.429.832.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany85.091.20.066.076.096.299.264.081.089.699.065.173.088.694.362.574.793.392.863.077.391.592.363.983.585.696.164.173.085.487.461.879.986.189.759.768.188.796.670.178.690.00.063.774.1

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value286316211494354241179520280288166533385273225581398254145691325220140626237256125561322246171567261185-1816.0635363-422.014855031622719889331298245485365321
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax19.420.20.030.325.316.713.631.320.318.511.730.924.617.216.033.725.916.810.737.222.815.310.734.216.916.59.133.622.715.412.934.618.612.5-120.331.721.9-25.59.424.317.711.911.63.919.215.414.526.621.516.6

us-gaap:OperatingIncomeLoss dei:LegalEntity

aee:AmerenIllinoisCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1412281561241341881501101041861351131051591501281301727423010713374189831209715875120851588785511518689751969988106182112
Percentage of OperatingIncomeLoss49.372.273.925.137.978.083.821.237.164.681.321.227.358.266.722.032.767.751.033.332.960.552.930.235.046.977.628.223.348.849.727.933.345.9-2.823.823.7-21.150.735.631.338.853.5204.533.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.614.60.07.69.613.111.46.67.512.09.56.66.710.010.77.48.511.45.512.47.59.35.710.35.97.77.19.55.37.56.49.66.25.83.47.55.25.44.88.65.64.66.28.06.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany22.427.70.021.123.626.022.919.519.024.420.020.018.220.922.322.322.624.512.434.019.719.613.428.916.216.115.327.614.515.515.128.916.912.48.723.315.212.312.326.315.910.90.024.417.3

aee:UnionElectricCompany


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1216231340190265.0381152797.039425890404172375354431197635842314611529394243119964171791116942926978233331767739385197
Percentage of OperatingIncomeLoss42.319.614.768.853.710.82.873.354.327.44.273.967.033.017.871.859.520.937.262.460.628.641.467.661.644.923.270.275.548.456.173.568.660.0-3.867.674.1-18.515.560.555.733.919.7432.659.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.24.00.020.913.61.80.423.011.05.10.522.916.55.72.924.215.43.54.023.213.84.44.423.110.47.42.123.617.17.57.325.512.87.54.621.416.24.71.514.79.94.02.317.011.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany15.08.80.034.024.03.80.836.019.010.41.034.927.011.45.737.425.46.77.237.022.78.57.736.116.514.43.935.927.014.612.638.220.113.910.340.331.911.33.429.921.410.00.036.325.9

Other Income

us-gaap:OtherIncome

us-gaap:OtherIncome


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
Value7.04.03.01.07.02.00.02.01.02.03.02.02.01.00.00.01.00.04.01.01.01.00.00.00.03.02.02.03.02.01.01.00.00.00.01.00.01.01.00.00.02.00.01.03.01.0
Percentage of OtherIncome100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.00.0100.00.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.0100.0100.00.00.0100.00.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.30.00.10.50.10.00.10.10.10.20.10.10.10.00.00.10.00.30.10.10.10.00.00.00.20.10.10.20.10.10.10.00.00.00.00.00.10.10.00.00.10.00.00.20.1

us-gaap:OtherIncome dei:LegalEntity

aee:AmerenIllinoisCompany


Other
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-312012-09-302012-06-302011-12-312011-09-30
Value3.00.01.04.01.00.01.01.01.00.01.02.00.00.00.01.03.01.01.00.0-1.00.00.02.03.01.03.01.01.01.00.00.01.01.01.00.0
Percentage of OtherIncome42.90.0100.057.150.00.050.0100.050.00.050.0100.00.00.00.0100.075.0100.0100.00.00.00.00.066.7150.050.0100.050.0100.0100.00.00.0100.00.0100.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.00.10.30.10.00.10.10.10.00.10.10.00.00.00.10.20.10.10.0-0.10.00.00.10.20.10.20.10.10.10.00.00.00.10.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany0.50.00.20.70.10.00.20.20.10.00.20.30.00.00.00.20.50.10.20.0-0.20.00.00.30.50.20.60.10.20.20.00.00.20.20.20.0

aee:UnionElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.01.01.01.01.01.01.02.02.01.01.02.00.01.02.00.01.00.00.00.00.01.02.00.00.00.0
Percentage of OtherIncome0.025.033.3100.014.350.00.0100.0200.050.033.3100.00.0100.00.00.0100.00.00.00.00.0100.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.10.00.10.10.10.10.10.10.10.10.10.00.10.10.00.10.00.00.00.00.10.20.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany0.00.10.00.10.10.10.20.20.30.10.10.20.00.10.30.00.10.00.00.00.00.10.30.00.00.0

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
Value494634484821313436291832292312119.06.09.010.010.013121410.08.01714179.010.015117.09.010.0132.010.01312116.0142215
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 RevenueFromContractWithCustomerIncludingAssessedTax3.32.90.02.93.41.52.42.02.61.91.31.91.91.50.90.60.60.40.70.50.70.90.90.80.70.51.20.81.20.60.80.90.80.50.60.50.80.10.60.60.70.60.40.61.30.8

us-gaap:OtherNonoperatingIncomeExpense dei:LegalEntity

aee:AmerenIllinoisCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-06-30
Value161414171711141315111211136.02.01.01.0-3.05.01.03.00.04.01.02.02.04.02.04.0-1.01.01.01.0-2.00.00.00.0-10.00.00.00.01.01.0
Percentage of OtherNonoperatingIncomeExpense32.730.441.235.435.452.445.238.241.737.966.734.444.826.116.79.111.1-50.055.610.030.00.033.37.120.025.023.514.323.5-11.110.06.79.1-28.60.00.00.0-500.00.00.00.09.14.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.10.90.01.01.20.81.10.81.10.70.80.60.80.40.10.10.1-0.20.40.10.20.00.30.10.10.10.30.10.3-0.10.10.10.1-0.10.00.00.0-0.60.00.00.00.10.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany2.51.70.02.93.01.52.12.32.71.41.82.02.20.80.30.20.2-0.40.80.10.60.00.70.20.40.30.60.30.8-0.10.20.20.2-0.30.00.00.0-1.40.00.00.00.10.2

aee:UnionElectricCompany


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
Value24232126254.0151516121116161310.0119.010.010.0127.013121110.08.013111410.01314119.01211141214141310.0171519
Percentage of OtherNonoperatingIncomeExpense49.050.061.854.252.119.048.444.144.441.461.150.055.256.583.3100.0100.0166.7111.1120.070.0100.0100.078.6100.0100.076.578.682.4111.1130.093.3100.0128.6133.3110.0107.7600.0140.0107.7108.390.9283.3107.186.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.61.50.01.61.80.31.10.91.20.80.80.91.00.80.70.60.60.70.70.60.50.90.90.60.70.50.90.71.00.61.00.90.80.60.80.50.80.70.90.60.70.51.00.71.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany3.03.30.02.63.20.62.41.42.01.61.51.41.71.61.41.01.01.31.31.00.81.81.60.91.11.01.81.01.61.21.71.31.21.11.81.01.71.72.11.31.61.30.01.42.5

Preferred Stock Dividends Income Statement Impact

us-gaap:PreferredStockDividendsIncomeStatementImpact dei:LegalEntity

us-gaap:PreferredStockDividendsIncomeStatementImpact

aee:AmerenIllinoisCompany


Preferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.001000000.02000000.0
Percentage of PreferredStockDividendsIncomeStatementImpact0.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.00.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.10.00.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.00.00.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany0.00.10.00.00.20.10.20.00.20.10.10.00.20.10.10.00.20.10.20.00.20.10.20.00.20.10.20.00.20.10.20.00.20.10.20.00.20.10.20.00.20.10.00.10.3

aee:UnionElectricCompany


Preferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.001000000.01000000.01000000.01000000.01000000.02000000.0
Percentage of PreferredStockDividendsIncomeStatementImpact0.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.00.0100.0100.00.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.00.10.10.00.00.10.10.10.00.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany0.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.10.10.00.10.3

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2082351163692441489536618019369359240153-59.0290194104333711481073034515111049295150983830496-143.0-1155.0374210-403.0262871397454-164.0155106
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.115.00.022.717.510.37.222.113.112.44.920.815.49.7-4.216.812.66.92.420.010.47.52.318.810.87.13.617.710.66.12.918.66.8-9.7-76.518.712.7-24.31.612.77.83.93.2-7.29.05.5

us-gaap:ProfitLoss dei:LegalEntity

aee:AmerenIllinoisCompany


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value861501007784121976563121856363967855588030119466033983254467529542277323212713328269838343711057
Percentage of ProfitLoss41.363.886.220.934.481.8102.117.835.062.7123.217.526.262.7-132.219.029.976.990.932.131.156.1110.028.421.249.193.925.419.355.157.925.333.3-22.4-1.019.015.7-6.9100.034.127.345.968.5-67.136.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.60.04.76.08.47.43.94.67.86.03.74.06.15.63.23.85.32.26.43.24.22.55.32.33.53.44.52.03.41.74.72.32.20.83.52.01.71.64.32.11.82.24.93.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany13.718.20.013.114.816.714.811.511.515.912.611.210.912.611.69.610.111.45.017.68.58.96.015.06.27.27.313.15.67.03.914.16.24.72.011.05.93.94.313.26.14.20.014.78.8

aee:UnionElectricCompany


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value11248-3.0298153-9.0-20.030110840-22.029516939-36.02351216.010.02429315112406242-5.0223127483323985411623714422-14.019191222.0224115
Percentage of ProfitLoss53.820.4-2.680.862.7-6.1-21.182.260.020.7-31.982.270.425.561.081.062.45.830.365.262.814.036.769.641.138.2-10.275.684.749.086.878.688.5-28.7-1.463.468.6-5.5-53.866.665.529.73.7-136.674.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.63.10.018.310.9-0.6-1.518.17.82.6-1.617.110.82.5-2.613.67.90.40.713.06.51.00.813.14.42.7-0.413.48.93.02.514.66.12.81.111.88.71.3-0.98.45.11.20.19.96.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany13.86.80.029.819.3-1.3-3.228.413.55.3-3.126.117.74.9-5.221.113.00.81.320.810.72.01.520.57.05.2-0.720.314.15.94.321.99.65.22.422.317.13.2-2.117.111.12.80.021.115.1

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

aee:AmerenIllinoisCompany, us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value86150100778412197656312185636396
Percentage of ProfitLoss41.363.886.220.934.481.8102.117.835.062.7123.217.526.262.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.60.04.76.08.47.43.94.67.86.03.74.06.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value11248-3.0298153-9.0-20.030110840-22.029516939
Percentage of ProfitLoss53.820.4-2.680.862.7-6.1-21.182.260.020.7-31.982.270.425.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.63.10.018.310.9-0.6-1.518.17.82.6-1.617.110.82.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value14721566132816281398144013161659137915561419172415631585140217231537151413561859142714341308183314011556137016701419159413221638140314751509200116601658157822681781190417062267172519401684182416961931
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312009-09-302009-06-302009-03-31
Value14721566132816281398144013161640137915561419172415631585140217231538151413561859142714341308183314011556137016701419159413221638140314751509200116601658157822681781190417062267172519401684182416961931
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.098.9100.0100.0100.0100.0100.0100.0100.0100.0100.1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues dei:LegalEntity

aee:AmerenIllinoisCompany


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value629823656589567723654564547762674564578760674575576703595676542677553655513745633572519774564547516684589648564724611745623808710746647
Percentage of Revenues42.752.649.436.240.650.249.734.439.749.047.532.737.047.948.133.437.546.443.936.438.047.242.335.736.647.946.234.336.648.642.733.436.846.439.032.434.043.738.732.835.042.441.632.937.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax42.752.649.436.240.650.249.734.039.749.047.532.737.047.948.133.437.546.443.936.438.047.242.335.736.647.946.234.336.648.642.733.436.846.439.032.434.043.738.732.835.042.441.632.937.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.2100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0

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

aee:AmerenIllinoisCompany, us-gaap:IntersegmentElimination


Revenuesdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-15.0-16.0-13.0-15.0-12.0-12.0-62.00.00.00.00.00.00.00.00.00.00.00.0350.00.00.0
Percentage of Revenues-1.0-1.0-1.0-0.9-0.9-0.8-4.70.00.00.00.00.00.00.00.00.00.00.02.60.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.0-1.0-1.0-0.9-0.9-0.8-4.70.00.00.00.00.00.00.00.00.00.00.02.60.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:IntersegmentElimination100.0100.00.0100.0100.0100.00.0-0.0-0.0-0.00.0-0.0-0.0-0.00.0-0.0-0.0-0.00.0-0.0-0.0-0.0

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

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, srt:NaturalGasReserves, aee:AmerenIllinoisGasSegment


Revenuesdei:
Period End2021-06-302021-03-312020-06-302020-03-31
Value168347140271
Percentage of Revenues11.422.210.018.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax11.422.210.018.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments srt:NaturalGasReserves aee:AmerenIllinoisGasSegment0.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, us-gaap:Electricity, aee:AmerenIllinoisElectricDistributionSegment


Revenuesdei:
Period End2021-06-302021-03-312020-06-302020-03-31
Value388411352390
Percentage of Revenues26.426.225.227.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax26.426.225.227.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments us-gaap:Electricity aee:AmerenIllinoisElectricDistributionSegment0.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, us-gaap:Electricity, aee:AmerenIllinoisTransmissionSegment


Revenuesdei:
Period End2021-06-302021-03-312020-06-302020-03-31
Value88818774
Percentage of Revenues6.05.26.25.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.05.26.25.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments us-gaap:Electricity aee:AmerenIllinoisTransmissionSegment0.00.00.00.0

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

aee:UnionElectricCompany, aee:FinalRateOrder


Revenuesdei:
Period End2021-06-302021-03-31
Value0.04.0
Percentage of Revenues0.00.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany aee:FinalRateOrder0.00.0

us-gaap:Revenues dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility

aee:UnionElectricCompany, aee:FinalRateOrder, us-gaap:Electricity


Revenuesdei:
Period End2020-12-312020-09-302020-06-302020-03-31
Value0.00.00.020
Percentage of Revenues0.00.00.01.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.01.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany aee:FinalRateOrder us-gaap:Electricity0.00.00.00.0

us-gaap:Revenues dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:RegulatoryAsset

aee:UnionElectricCompany, aee:FinalRateOrder, us-gaap:Electricity, aee:MEEIA2019


Revenuesdei:
Period End2020-09-30
Value6.0
Percentage of Revenues0.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany aee:FinalRateOrder us-gaap:Electricity aee:MEEIA20190.0

us-gaap:Revenues dei:LegalEntity, us-gaap:PublicUtilitiesRegulatoryProceeding, us-gaap:PublicUtility, us-gaap:RegulatoryAsset, us-gaap:SubsequentEventType

aee:UnionElectricCompany, aee:FinalRateOrder, us-gaap:Electricity, aee:MEEIA2019, us-gaap:SubsequentEvent


Revenuesdei:
Period End2020-09-30
Value6.0
Percentage of Revenues0.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany aee:FinalRateOrder us-gaap:Electricity aee:MEEIA2019 us-gaap:SubsequentEvent0.0

us-gaap:Revenues us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-29.0-26.0-23.0-27.0-22.0-24.0-98.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.035-13.0
Percentage of Revenues-2.0-1.7-1.7-1.7-1.6-1.7-7.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.02.7-0.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.0-1.7-1.7-1.7-1.6-1.7-7.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.02.7-0.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination0.00.00.0100.0100.0100.00.0-0.0-0.0-0.00.0-0.0-0.0-0.00.0-0.0-0.0-0.00.0-0.0-0.0-0.00.0100.0

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

us-gaap:IntersegmentElimination, us-gaap:Electricity


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
Value-29.0-26.0-21.0-27.0-22.0-24.0-21.0-29.0-23.0-23.0-20.0-26.0-24.0-22.0
Percentage of Revenues-2.0-1.7-1.6-1.7-1.6-1.7-1.6-1.8-1.7-1.5-1.4-1.5-1.5-1.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.0-1.7-1.6-1.7-1.6-1.7-1.6-1.7-1.7-1.5-1.4-1.5-1.5-1.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination us-gaap:Electricity0.00.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0

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

us-gaap:OperatingSegments, srt:NaturalGasReserves, aee:AmerenIllinoisGasSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value168347140271
Percentage of Revenues11.422.210.018.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax11.422.210.018.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments srt:NaturalGasReserves aee:AmerenIllinoisGasSegment0.00.00.00.0

us-gaap:OperatingSegments, srt:NaturalGasReserves, aee:UnionElectricCompany


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value2063381721493619255444182551431722
Percentage of Revenues1.44.02.91.01.53.42.71.21.83.53.11.01.63.23.11.01.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.44.02.91.01.53.42.71.11.83.53.11.01.63.23.11.01.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments srt:NaturalGasReserves aee:UnionElectricCompany0.00.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0

us-gaap:OperatingSegments, us-gaap:Electricity, aee:AmerenIllinoisElectricDistributionSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value388411352390
Percentage of Revenues26.426.225.227.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax26.426.225.227.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments us-gaap:Electricity aee:AmerenIllinoisElectricDistributionSegment0.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Electricity, aee:AmerenTransmissionSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value136130136123
Percentage of Revenues9.28.39.78.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.28.39.78.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments us-gaap:Electricity aee:AmerenTransmissionSegment0.00.00.00.0

us-gaap:OperatingSegments, us-gaap:Electricity, aee:UnionElectricCompany


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value789641598984771631592104077370466911119307416531099912
Percentage of Revenues53.640.945.060.455.243.845.063.456.145.247.164.459.546.846.663.859.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax53.640.945.060.455.243.845.062.756.145.247.164.459.546.846.663.859.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments us-gaap:Electricity aee:UnionElectricCompany0.00.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0

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

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value388411352390
Percentage of Revenues26.426.225.227.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax26.426.225.227.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistributionSegment100.5100.0100.0100.3

us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value168347140271
Percentage of Revenues11.422.210.018.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax11.422.210.018.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisGasSegment100.0100.0100.0100.0

us-gaap:OperatingSegments, aee:AmerenTransmissionSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-31
Value136130136123
Percentage of Revenues9.28.39.78.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.28.39.78.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenTransmissionSegment114.3115.0109.7111.8

us-gaap:OperatingSegments, aee:UnionElectricCompany


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value809704636100179268065210507907517071118946784691110492377273611508577267411160
Percentage of Revenues55.045.047.961.556.747.249.564.057.348.349.864.860.549.549.364.160.051.054.361.960.150.656.763.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax55.045.047.961.556.747.249.563.357.348.349.864.860.549.549.364.160.151.054.361.960.150.656.763.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:UnionElectricCompany101.3101.30.0100.0100.0100.00.099.299.099.10.099.099.199.00.098.998.8100.00.0100.0100.0100.00.0100.0

us-gaap:Revenues us-gaap:ProductOrService

srt:NaturalGasReserves


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value188410263139161320263131161374289134167362275129155
Percentage of Revenues12.826.219.88.511.522.220.08.011.724.020.47.810.722.819.67.510.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.826.219.88.511.522.220.07.911.724.020.47.810.722.819.67.510.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:NaturalGasReserves100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0

us-gaap:Electricity


Revenuesus-gaap:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value12841156106514891237112010531528121811821130159013961223112415941382
Percentage of Revenues87.273.880.291.588.577.880.093.288.376.079.692.289.377.280.292.589.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax87.273.880.291.588.577.880.092.188.376.079.692.289.377.280.292.589.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:Electricity100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3391632789320303051730016292722893328546281032750927215269592663926079259452561725254248112469924134237932338523640234592315222884226762187621588211662104222385222762195221835234982298022899236452335623391233292351523702
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 dei:LegalEntity

aee:AmerenIllinoisCompany


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1431613972135351309912802124331218511946117241149411319110101077110471103451002298019569947492028999894489038656850084568381798377197640745474397366728872827227712772567213706471547406
Percentage of Assets42.242.642.342.942.742.542.141.841.741.841.640.840.440.239.939.138.838.638.438.137.838.237.736.936.737.037.036.535.836.135.433.233.133.233.430.831.031.730.530.230.631.5
Percentage of Assets42.242.642.342.942.742.542.141.841.741.841.640.840.440.239.939.138.838.638.438.137.838.237.736.936.737.037.036.535.836.135.433.233.133.233.430.831.031.730.530.230.631.5
Percentage of Assets aee:AmerenIllinoisCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

aee:UnionElectricCompany


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value178251697016783155231534714993149371486014698143711429114383143921404014043140681400513814140351388913649134431385113941137211355513541131791320312948129041323113131128671304312967126801254612757126381252712504
Percentage of Assets52.651.852.450.951.151.251.652.152.352.252.553.454.053.854.154.955.555.756.857.557.457.558.659.459.359.259.760.261.261.261.359.158.958.659.755.255.254.854.054.153.653.2
Percentage of Assets52.651.852.450.951.151.251.652.152.352.252.553.454.053.854.154.955.555.756.857.557.457.558.659.459.359.259.760.261.261.261.359.158.958.659.755.255.254.854.054.153.653.2
Percentage of Assets aee:UnionElectricCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidatedEntities

srt:ParentCompany


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-31
Value11203955989918448
Percentage of Assets35.033.033.032.6
Percentage of Assets35.033.033.032.6
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0

Liabilities

us-gaap:Liabilities us-gaap:ConsolidatedEntities

us-gaap:Liabilities

srt:ParentCompany


Liabilitiesus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-31
Value2265150013601264
Percentage of Liabilities100.0100.0100.0100.0
Percentage of Assets7.15.25.04.9
Percentage of Assets srt:ParentCompany20.215.715.115.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3391632789320303051730016292722893328546281032750927215269592663926079259452561725254248112469924134237932338523640234592315222884226762187621588211662104222385222762195221835234982298022899236452335623391233292351523702
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity

aee:AmerenIllinoisCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1431613972135351309912802124331218511946117241149411319110101077110471103451002298019569947492028999894489038656850084568381798377197640745474397366728872827227712772567213706471547406
Percentage of LiabilitiesAndStockholdersEquity42.242.642.342.942.742.542.141.841.741.841.640.840.440.239.939.138.838.638.438.137.838.237.736.936.737.037.036.535.836.135.433.233.133.233.430.831.031.730.530.230.631.5
Percentage of Assets42.242.642.342.942.742.542.141.841.741.841.640.840.440.239.939.138.838.638.438.137.838.237.736.936.737.037.036.535.836.135.433.233.133.233.430.831.031.730.530.230.631.5
Percentage of Assets aee:AmerenIllinoisCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

aee:UnionElectricCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value178251697016783155231534714993149371486014698143711429114383143921404014043140681400513814140351388913649134431385113941137211355513541131791320312948129041323113131128671304312967126801254612757126381252712504
Percentage of LiabilitiesAndStockholdersEquity52.651.852.450.951.151.251.652.152.352.252.553.454.053.854.154.955.555.756.857.557.457.558.659.459.359.259.760.261.261.261.359.158.958.659.755.255.254.854.054.153.653.2
Percentage of Assets52.651.852.450.951.151.251.652.152.352.252.553.454.053.854.154.955.555.756.857.557.457.558.659.459.359.259.760.261.261.261.359.158.958.659.755.255.254.854.054.153.653.2
Percentage of Assets aee:UnionElectricCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilities
Period End2020-12-312019-12-312018-12-312017-12-31
Value11203955989918448
Percentage of LiabilitiesAndStockholdersEquity35.033.033.032.6
Percentage of Assets35.033.033.032.6
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value935391488938848982278085805980627791770576317656738672307184734571587064710371936922686969467014676467046713677465726513654465746374636566167874755574327919772577307856
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.627.927.927.827.427.627.928.227.728.028.028.427.727.727.728.728.328.528.829.829.129.429.429.929.229.329.631.030.430.831.129.428.629.030.333.532.932.533.533.132.933.1

us-gaap:StockholdersEquity dei:LegalEntity

aee:AmerenIllinoisCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value5258514249664762468543524132402139563894377436103547342533103225317031133034302129382925289728412742271326612602252725002448249324312416240124472434244124522502249325763072
Percentage of StockholdersEquity56.256.255.656.156.953.851.349.950.850.549.547.248.047.446.143.944.344.142.742.042.442.641.740.540.540.539.638.438.538.437.437.938.138.036.331.132.232.831.00.00.033.339.1
Percentage of Assets15.515.715.515.615.614.914.314.114.114.213.913.413.313.112.812.612.612.512.312.512.312.512.312.111.811.911.711.911.711.811.611.110.911.011.010.410.610.710.410.710.711.013.0
Percentage of Assets aee:AmerenIllinoisCompany36.736.836.736.436.635.033.933.733.733.933.332.832.932.732.032.232.332.532.032.832.632.732.532.832.332.131.832.632.732.732.833.533.033.233.033.934.233.634.035.434.834.80.0

aee:UnionElectricCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value5551537052104788449143394349442542754268422943564237406940814117404340354090414739793956408241183954399440524121401139633993409639984004405441374001395840374235413041534057
Percentage of StockholdersEquity59.358.758.356.454.653.754.054.954.955.455.456.957.456.356.856.156.557.157.657.757.557.658.858.758.559.660.460.861.060.861.062.362.762.961.352.553.053.351.00.00.053.751.6
Percentage of Assets16.416.416.315.715.014.815.015.515.215.515.516.215.915.615.716.116.016.316.617.216.716.917.317.617.117.517.918.818.618.719.018.317.918.218.617.617.417.317.118.117.717.717.1
Percentage of Assets aee:UnionElectricCompany31.131.631.030.829.328.929.129.829.129.729.630.329.429.029.129.328.929.229.129.929.229.429.529.528.829.529.931.330.430.630.931.030.431.131.131.931.631.531.633.533.033.20.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:Parent


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value9353914889388489822780858059806277917705763176567386723071847103694667136544661679197730
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.627.927.927.827.427.627.928.227.728.028.028.427.727.727.728.829.429.631.130.333.532.9
Percentage of Assets us-gaap:Parent0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value21161823165315901620146414311495151414221533164016851567161215811571145015931599159414581917198319911993204619421965184019723273340832962369240621542124229526802603271528942842
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 Assets6.25.65.25.25.45.04.95.25.45.25.66.16.36.06.26.26.25.86.46.66.76.28.18.58.68.79.08.99.18.79.414.615.315.010.810.29.49.39.711.511.111.612.312.0

us-gaap:AssetsCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value99594164759960457161460961265767662957662667260260659268361758268676063270281184468560567763362571074774987490610611017110812011438
Percentage of AssetsCurrent47.051.639.137.737.339.042.940.740.446.244.138.434.239.941.738.138.640.842.938.636.547.139.631.935.340.741.335.330.836.832.119.120.822.731.636.342.150.044.341.346.149.7
Percentage of Assets2.92.92.02.02.02.02.12.12.22.42.52.32.22.42.62.42.42.42.82.62.42.93.22.73.03.53.73.12.83.23.02.83.23.43.43.73.94.64.34.75.16.1
Percentage of Assets aee:AmerenIllinoisCompany7.06.74.84.64.74.65.05.15.25.76.05.75.36.06.56.06.26.27.26.76.57.78.57.38.39.610.18.67.88.98.58.49.610.210.312.112.714.614.115.716.819.4

aee:UnionElectricCompany


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value127495111929689938588148829027518321042117290190596495078810041147974788118613251100964103910211117948959116511339791159119110238881134133911251275
Percentage of AssetsCurrent60.252.272.160.961.358.656.959.059.652.854.363.569.657.556.161.060.554.363.071.761.154.061.966.855.248.450.852.656.851.548.635.633.229.748.949.547.541.849.450.043.244.1
Percentage of Assets3.82.93.73.23.32.92.83.13.22.73.13.94.43.53.53.83.83.24.14.84.13.45.05.64.84.24.64.75.24.54.65.25.14.55.35.14.53.94.85.74.85.4
Percentage of Assets aee:UnionElectricCompany7.15.67.16.26.55.75.45.96.15.25.87.28.16.46.46.96.85.77.28.37.15.98.69.58.07.17.77.78.57.37.48.88.67.68.99.28.17.18.910.69.010.2

us-gaap:AssetsCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Assets
Period End2020-12-312019-12-312018-12-312017-12-31
Value4718212367
Percentage of AssetsCurrent2.812.78.04.2
Percentage of Assets0.10.60.50.3
Percentage of Assets srt:ParentCompany0.41.91.40.8

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
Value996.01396.08.04216206.08.01611293010.09.010.08.09.0181313292722.06.05.01346263016915016120929811720825552237857354560850636062292355
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 Assets0.30.00.40.00.00.10.10.10.00.00.10.00.10.10.00.00.00.00.00.10.10.11.20.30.00.00.00.10.20.10.10.80.70.71.01.30.50.91.12.21.62.52.30.00.00.02.60.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity

aee:AmerenIllinoisCompany


Cash
Period End2021-06-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-312008-12-31
Value962.06.00.00.00.00.00.00.00.03.00.00.00.00.00.03.00.00.0710.00.00.01.01.02.01.01.01.098930.093601872111625350832228538330650
Percentage of CashAndCashEquivalentsAtCarryingValue97.025.014.30.00.00.00.00.00.00.010.00.00.00.00.00.016.70.00.024.30.00.00.020.07.74.33.83.30.665.357.80.031.251.389.98.222.266.988.759.146.975.749.254.3
Percentage of Assets0.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.30.00.00.00.00.00.00.00.00.00.40.40.00.40.30.80.10.51.12.21.40.00.01.30.0
Percentage of Assets aee:AmerenIllinoisCompany0.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.80.00.00.00.00.00.00.00.00.01.31.30.01.30.82.60.31.63.50.04.30.00.00.00.0

aee:UnionElectricCompany


Cash
Period End2021-03-312020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-31
Value1.01360.03.09.00.00.00.00.00.0173.00.00.00.00.00.01.00.00.0199690.01.01.01.0280.01.0100191.01481320.03.0201356793820229191267
Percentage of CashAndCashEquivalentsAtCarryingValue16.797.80.07.156.20.00.00.00.00.058.610.00.00.00.00.00.05.60.00.068.295.80.016.720.07.760.90.03.359.212.70.670.844.30.01.478.868.220.96.637.147.918.042.9
Percentage of Assets0.00.40.00.00.00.00.00.00.00.00.10.00.00.00.00.00.00.00.00.00.80.30.00.00.00.00.10.00.00.40.10.00.70.60.00.00.91.50.30.20.90.00.01.1
Percentage of Assets aee:UnionElectricCompany0.00.80.00.00.10.00.00.00.00.00.10.00.00.00.00.00.00.00.00.01.40.50.00.00.00.00.20.00.00.80.10.01.11.00.00.01.62.80.60.01.60.00.00.0

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

aee:UnionElectricCompany, us-gaap:Cash


Cash
Period End2020-12-312019-12-312018-12-31
Value4.0263.0
Percentage of CashAndCashEquivalentsAtCarryingValue2.9162.518.8
Percentage of Assets0.00.10.0
Percentage of Assets aee:UnionElectricCompany us-gaap:Cash0.00.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value26717230116816320317615512211810792968968575352351
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.50.90.60.50.70.60.50.40.40.40.30.40.30.30.20.20.21.5

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents dei:LegalEntity

aee:AmerenIllinoisCompany


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value2421491471471421401251179993807157524132282899
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents90.686.648.887.587.169.071.075.581.178.874.877.259.458.460.356.152.853.828.2
Percentage of Assets0.70.50.50.50.50.50.40.40.40.30.30.30.20.20.20.10.10.10.4
Percentage of Assets aee:AmerenIllinoisCompany1.71.11.11.11.11.11.01.00.80.80.70.60.50.50.40.30.30.31.1

aee:UnionElectricCompany


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value171214510.01124391413128.07.02510.07.06.05.05.0207
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents6.47.048.26.06.711.822.29.010.710.27.57.626.011.210.310.59.49.659.0
Percentage of Assets0.10.00.50.00.00.10.10.00.00.00.00.00.10.00.00.00.00.00.9
Percentage of Assets aee:UnionElectricCompany0.10.10.90.10.10.20.30.10.10.10.10.00.20.10.00.00.00.01.5

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

aee:AmerenIllinoisCompany, us-gaap:FairValueInputsLevel1, us-gaap:EstimateOfFairValueFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value242149147147142140125117999380715741
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents90.686.648.887.587.169.071.075.581.178.874.877.259.460.3
Percentage of Assets0.70.50.50.50.50.50.40.40.40.30.30.30.20.2
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:FairValueInputsLevel1 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:FairValueInputsLevel1, us-gaap:EstimateOfFairValueFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value171214510.01124391413128.07.0257.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents6.47.048.26.06.711.822.29.010.710.27.57.626.010.3
Percentage of Assets0.10.00.50.00.00.10.10.00.00.00.00.00.10.0
Percentage of Assets aee:UnionElectricCompany us-gaap:FairValueInputsLevel1 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

aee:AmerenIllinoisCompany, us-gaap:CarryingReportedAmountFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value2421491471471421401251179993807141
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents90.686.648.887.587.169.071.075.581.178.874.877.260.3
Percentage of Assets0.70.50.50.50.50.50.40.40.40.30.30.30.2
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:EstimateOfFairValueFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value242149147147142140125117999380715741
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents90.686.648.887.587.169.071.075.581.178.874.877.259.460.3
Percentage of Assets0.70.50.50.50.50.50.40.40.40.30.30.30.20.2
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:CarryingReportedAmountFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value171214510.01124391413128.07.0257.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents6.47.048.26.06.711.822.29.010.710.27.57.626.010.3
Percentage of Assets0.10.00.50.00.00.10.10.00.00.00.00.00.10.0
Percentage of Assets aee:UnionElectricCompany us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:EstimateOfFairValueFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value171214510.01124391413128.07.0257.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents6.47.048.26.06.711.822.29.010.710.27.57.626.010.3
Percentage of Assets0.10.00.50.00.00.10.10.00.00.00.00.00.10.0
Percentage of Assets aee:UnionElectricCompany us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents us-gaap:ConsolidatedEntities

srt:ParentCompany


Cash
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value4.03.01.08.09.08.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents1.31.70.911.817.32.3
Percentage of Assets0.00.00.00.00.00.0
Percentage of Assets srt:ParentCompany0.00.00.00.10.00.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis

us-gaap:FairValueInputsLevel1, us-gaap:EstimateOfFairValueFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value267172301168163203176155122118107929668
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.50.90.60.50.70.60.50.40.40.40.30.40.3
Percentage of Assets us-gaap:FairValueInputsLevel1 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value267172301168163203176155122118107929668
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.50.90.60.50.70.60.50.40.40.40.30.40.3
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:EstimateOfFairValueFairValueDisclosure


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value267172301168163203176155122118107929668
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.50.90.60.50.70.60.50.40.40.40.30.40.3
Percentage of Assets us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value397464415525486456393478461517463605560514445507446457437543445428388508456524423467454553404469425479401523417446473575507517500424
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.21.41.31.71.61.61.41.71.61.91.72.22.12.01.72.01.81.81.82.21.91.81.62.22.02.31.92.12.12.61.92.11.92.21.82.21.81.92.02.52.22.22.11.8

us-gaap:AccountsReceivableNetCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value212293234247256268215222225315224251251298234219219270242259225262204229207304212192221328201185185274182197175228201194197230
Percentage of AccountsReceivableNetCurrent53.463.156.447.052.758.854.746.448.860.948.441.544.858.052.643.249.159.155.447.750.661.252.645.145.458.050.141.148.759.349.839.443.557.245.437.742.051.142.533.738.946.0
Percentage of Assets0.60.90.70.80.90.90.70.80.81.10.80.90.91.10.90.90.91.11.01.10.91.10.91.00.91.30.90.91.01.51.00.80.81.20.80.80.81.00.90.80.81.0
Percentage of Assets aee:AmerenIllinoisCompany1.52.11.71.92.02.21.81.91.92.72.02.32.32.82.32.22.22.82.62.82.52.92.32.62.43.62.52.42.94.32.72.52.53.82.52.72.53.12.82.72.83.1

aee:UnionElectricCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value168156166263216174164243221189223331285205200274212175187272206150174260227202190261217218191270229202161263180170212308236217
Percentage of AccountsReceivableNetCurrent42.333.640.050.144.438.241.750.847.936.648.254.750.939.944.954.047.538.342.850.146.335.044.851.249.838.544.955.947.839.447.357.653.942.240.150.343.238.144.853.646.543.4
Percentage of Assets0.50.50.50.90.70.60.60.90.80.70.81.21.10.80.81.10.80.70.81.10.90.60.71.11.00.90.81.21.01.00.91.21.00.90.71.10.80.70.91.31.00.9
Percentage of Assets aee:UnionElectricCompany0.90.91.01.71.41.21.11.61.51.31.62.32.01.51.41.91.51.31.32.01.51.11.31.91.71.51.42.01.61.71.52.01.71.61.22.01.41.41.72.41.91.7

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
Value527467521557514471494488433402483525475453522547512467527551515483538548500449524561491424526581511461704756686625712734654572707782
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 Assets1.61.41.61.81.71.61.71.71.51.51.81.91.81.72.02.12.01.92.12.32.22.12.32.32.22.02.32.62.32.02.52.62.32.13.23.23.02.73.03.12.82.53.03.3

us-gaap:InventoryNet dei:LegalEntity

aee:AmerenIllinoisCompany


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1321051351491088012113297731251409570134151114861351591199415117412988177211138861742111418617320213796199239145198
Percentage of InventoryNet25.022.525.926.821.017.024.527.022.418.225.926.720.015.525.727.622.318.425.628.923.119.528.131.825.819.633.837.628.120.333.136.327.618.724.626.720.015.427.932.622.228.0
Percentage of Assets0.40.30.40.50.40.30.40.50.30.30.50.50.40.30.50.60.50.30.50.70.50.40.60.70.60.40.81.00.60.40.80.90.60.40.80.90.60.40.81.00.60.8
Percentage of Assets aee:AmerenIllinoisCompany0.90.81.01.10.80.61.01.10.80.61.11.30.90.71.31.51.20.91.41.71.31.11.72.01.51.02.12.61.81.12.32.81.91.22.42.81.91.32.83.42.02.7

aee:UnionElectricCompany


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value395362386408406391373356336329358385380383388396399381392392396389387374371361347350352338352370369375397402388365348337343341
Percentage of InventoryNet75.077.574.173.279.083.075.573.077.681.874.173.380.084.574.372.477.981.674.471.176.980.571.968.274.280.466.262.471.779.766.963.772.281.356.453.256.658.448.945.952.448.2
Percentage of Assets1.21.11.21.31.41.31.31.21.21.21.31.41.41.51.51.51.61.51.61.61.71.71.61.61.61.61.51.61.61.61.71.71.71.71.81.71.71.61.51.41.51.5
Percentage of Assets aee:UnionElectricCompany2.22.12.32.62.62.62.52.42.32.32.52.72.62.72.82.82.82.82.82.82.92.92.82.72.72.72.62.72.72.62.72.82.82.93.03.13.12.92.72.72.72.7

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
Value1651141352101311271181069070638372849896971059876686388103959186666870851081046095989913413213210410010998
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 Assets0.50.30.40.70.40.40.40.40.30.30.20.30.30.30.40.40.40.40.40.30.30.30.40.40.40.40.40.30.30.30.40.50.50.30.40.40.40.60.60.60.40.40.50.4

us-gaap:OtherAssetsCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value38242931353129262415161810.0121518111625171113151610.0131517142026332936474710.01165108109106
Percentage of OtherAssetsCurrent23.021.121.514.826.724.424.624.526.721.425.421.713.914.315.318.811.315.225.522.416.220.617.015.510.514.317.425.820.628.630.630.627.960.049.548.010.18.249.281.8104.897.2
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.00.00.10.10.00.10.10.10.00.10.10.10.00.10.10.10.10.10.10.10.10.20.20.20.00.00.30.50.50.5
Percentage of Assets aee:AmerenIllinoisCompany0.30.20.20.20.30.20.20.20.20.10.10.20.10.10.10.20.10.20.30.20.10.10.20.20.10.20.20.20.20.30.30.40.40.50.60.70.10.20.91.51.51.4

aee:UnionElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value106707911991966666523226404248504343454937332941578977924082507165100516963662482681420
Percentage of OtherAssetsCurrent64.261.458.556.769.575.655.962.357.845.741.348.258.357.151.044.844.342.950.048.748.546.046.655.393.784.6107.060.6120.671.483.560.296.285.072.664.366.717.962.151.513.518.3
Percentage of Assets0.30.20.20.40.30.30.20.20.20.10.10.10.20.20.20.20.20.20.20.20.10.10.20.20.40.30.40.20.40.20.30.30.40.20.30.30.30.10.30.30.10.1
Percentage of Assets aee:UnionElectricCompany0.60.40.50.80.60.60.40.40.40.20.20.30.30.30.40.30.30.30.30.30.20.20.30.40.60.60.70.30.60.40.60.50.80.40.50.50.50.20.60.50.10.2

us-gaap:OtherAssetsCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value4.03.04.08.0
Percentage of OtherAssetsCurrent3.02.56.38.2
Percentage of Assets0.00.00.00.0
Percentage of Assets srt:ParentCompany0.00.00.00.1

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value397193665234002320273011827603261982370123909264682615424475
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets124.0126.7124.9123.4121.9116.8115.5112.6109.5111.9111.2103.3

us-gaap:PropertyPlantAndEquipmentGross dei:LegalEntity

aee:AmerenIllinoisCompany


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value146021341712181111231020892508371698864466052
Percentage of PropertyPlantAndEquipmentGross36.836.635.834.733.933.532.029.527.022.9
Percentage of Assets45.646.444.842.941.339.136.933.229.525.6
Percentage of Assets aee:AmerenIllinoisCompany107.9110.1107.6107.5107.7103.999.993.788.583.9

aee:OtherAffiliatedEntitiesAndIntercompanyEliminations


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2019187816151409951387344336
Percentage of PropertyPlantAndEquipmentGross5.15.14.74.43.21.41.31.4
Percentage of Assets6.36.55.95.43.91.61.51.6
Percentage of Assets aee:OtherAffiliatedEntitiesAndIntercompanyEliminations0.00.00.00.00.00.00.00.0

aee:UnionElectricCompany


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value23098213572020619495189591796617483163771603115484
Percentage of PropertyPlantAndEquipmentGross58.258.359.460.962.965.166.769.167.158.5
Percentage of Assets72.173.874.275.176.876.077.177.873.465.5
Percentage of Assets aee:UnionElectricCompany137.6143.0141.4138.8135.1129.7129.1126.9122.9121.4

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

aee:AmerenIllinoisCompany, aee:Electricdistributionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value664962995970564952874952
Percentage of PropertyPlantAndEquipmentGross16.717.217.617.617.617.9
Percentage of Assets20.821.821.921.821.420.9
Percentage of Assets aee:AmerenIllinoisCompany aee:Electricdistributionequipment0.00.00.00.00.00.0

aee:AmerenIllinoisCompany, aee:Electrictransmissionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value357531012647229820161674
Percentage of PropertyPlantAndEquipmentGross9.08.57.87.26.76.1
Percentage of Assets11.210.79.78.98.27.1
Percentage of Assets aee:AmerenIllinoisCompany aee:Electrictransmissionequipment0.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value3308302427012419218619971854156214611368
Percentage of PropertyPlantAndEquipmentGross8.38.37.97.67.37.27.16.66.15.2
Percentage of Assets10.310.59.99.38.98.48.27.46.75.8
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:GasDistributionEquipment0.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:PropertyPlantAndEquipmentOtherTypes


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value1070993863757719627
Percentage of PropertyPlantAndEquipmentGross2.72.72.52.42.42.3
Percentage of Assets3.33.43.22.92.92.7
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:PropertyPlantAndEquipmentOtherTypes0.00.00.00.00.00.0

aee:OtherAffiliatedEntitiesAndIntercompanyEliminations, aee:Electrictransmissionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value1774164213851167712121
Percentage of PropertyPlantAndEquipmentGross4.54.54.13.62.40.4
Percentage of Assets5.55.75.14.52.90.5
Percentage of Assets aee:OtherAffiliatedEntitiesAndIntercompanyEliminations aee:Electrictransmissionequipment0.00.00.00.00.00.0

aee:OtherAffiliatedEntitiesAndIntercompanyEliminations, us-gaap:PropertyPlantAndEquipmentOtherTypes


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value245236230242239266
Percentage of PropertyPlantAndEquipmentGross0.60.60.70.80.81.0
Percentage of Assets0.80.80.80.91.01.1
Percentage of Assets aee:OtherAffiliatedEntitiesAndIntercompanyEliminations us-gaap:PropertyPlantAndEquipmentOtherTypes0.00.00.00.00.00.0

aee:UnionElectricCompany, aee:CoalFiredElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value48754730
Percentage of PropertyPlantAndEquipmentGross12.312.9
Percentage of Assets15.216.3
Percentage of Assets aee:UnionElectricCompany aee:CoalFiredElectricGenerationEquipment0.00.0

aee:UnionElectricCompany, aee:Electricdistributionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value678463715989576655635303
Percentage of PropertyPlantAndEquipmentGross17.117.417.618.018.519.2
Percentage of Assets21.222.022.022.222.522.4
Percentage of Assets aee:UnionElectricCompany aee:Electricdistributionequipment0.00.00.00.00.00.0

aee:UnionElectricCompany, aee:Electrictransmissionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value14821405127712011151979
Percentage of PropertyPlantAndEquipmentGross3.73.83.83.73.83.5
Percentage of Assets4.64.94.74.64.74.1
Percentage of Assets aee:UnionElectricCompany aee:Electrictransmissionequipment0.00.00.00.00.00.0

aee:UnionElectricCompany, aee:NaturalGasAndOilFiredElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value10971090
Percentage of PropertyPlantAndEquipmentGross2.83.0
Percentage of Assets3.43.8
Percentage of Assets aee:UnionElectricCompany aee:NaturalGasAndOilFiredElectricGenerationEquipment0.00.0

aee:UnionElectricCompany, aee:NuclearPoweredElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value56085414
Percentage of PropertyPlantAndEquipmentGross14.114.8
Percentage of Assets17.518.7
Percentage of Assets aee:UnionElectricCompany aee:NuclearPoweredElectricGenerationEquipment0.00.0

aee:UnionElectricCompany, aee:RenewableElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value1301646
Percentage of PropertyPlantAndEquipmentGross3.31.8
Percentage of Assets4.12.2
Percentage of Assets aee:UnionElectricCompany aee:RenewableElectricGenerationEquipment0.00.0

aee:UnionElectricCompany, us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value561528500474455445431413393385
Percentage of PropertyPlantAndEquipmentGross1.41.41.51.51.51.61.61.71.61.5
Percentage of Assets1.81.81.81.81.81.91.92.01.81.6
Percentage of Assets aee:UnionElectricCompany us-gaap:GasDistributionEquipment0.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:PropertyPlantAndEquipmentOtherTypes


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value139011731008922879808
Percentage of PropertyPlantAndEquipmentGross3.53.23.02.92.92.9
Percentage of Assets4.34.13.73.63.63.4
Percentage of Assets aee:UnionElectricCompany us-gaap:PropertyPlantAndEquipmentOtherTypes0.00.00.00.00.00.0

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType

aee:CoalFiredElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value48754730
Percentage of PropertyPlantAndEquipmentGross12.312.9
Percentage of Assets15.216.3
Percentage of Assets aee:CoalFiredElectricGenerationEquipment0.00.0

aee:Electricdistributionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value134331267011959114151085010255
Percentage of PropertyPlantAndEquipmentGross33.834.635.235.636.037.2
Percentage of Assets41.943.843.944.043.943.4
Percentage of Assets aee:Electricdistributionequipment0.00.00.00.00.00.0

aee:Electrictransmissionequipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value683161485309466638792774
Percentage of PropertyPlantAndEquipmentGross17.216.815.614.612.910.0
Percentage of Assets21.321.219.518.015.711.7
Percentage of Assets aee:Electrictransmissionequipment0.00.00.00.00.00.0

aee:NaturalGasAndOilFiredElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value10971090
Percentage of PropertyPlantAndEquipmentGross2.83.0
Percentage of Assets3.43.8
Percentage of Assets aee:NaturalGasAndOilFiredElectricGenerationEquipment0.00.0

aee:NuclearPoweredElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value56085414
Percentage of PropertyPlantAndEquipmentGross14.114.8
Percentage of Assets17.518.7
Percentage of Assets aee:NuclearPoweredElectricGenerationEquipment0.00.0

aee:RenewableElectricGenerationEquipment


Property
Period End2020-12-312019-12-31
Value1301646
Percentage of PropertyPlantAndEquipmentGross3.31.8
Percentage of Assets4.12.2
Percentage of Assets aee:RenewableElectricGenerationEquipment0.00.0

us-gaap:GasDistributionEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value386935523201289326412442228519751854174616611583
Percentage of PropertyPlantAndEquipmentGross9.79.79.49.08.88.88.78.37.86.66.46.5
Percentage of Assets12.112.311.811.210.710.310.19.48.57.47.16.7
Percentage of Assets us-gaap:GasDistributionEquipment0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PropertyPlantAndEquipmentOtherTypes


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value270524022101192118371701
Percentage of PropertyPlantAndEquipmentGross6.86.66.26.06.16.2
Percentage of Assets8.48.37.77.47.47.2
Percentage of Assets us-gaap:PropertyPlantAndEquipmentOtherTypes0.00.00.00.00.00.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value137731300612273116331096110347975986448823942991948787
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets43.045.045.144.844.443.843.041.140.439.939.137.1

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment dei:LegalEntity

aee:AmerenIllinoisCompany


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value3780353632943082285026322422162714951364
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment27.427.226.826.526.025.424.818.816.914.5
Percentage of Assets11.812.212.111.911.511.110.77.76.85.8
Percentage of Assets aee:AmerenIllinoisCompany27.929.029.129.830.129.628.921.820.518.9

aee:OtherAffiliatedEntitiesAndIntercompanyEliminations


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value304275253246231255251251
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment2.22.12.12.12.12.52.62.9
Percentage of Assets0.91.00.90.90.91.11.11.2
Percentage of Assets aee:OtherAffiliatedEntitiesAndIntercompanyEliminations0.00.00.00.00.00.00.00.0

aee:UnionElectricCompany


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value9689919587268305788074607086676666146276
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment70.370.771.171.471.972.172.678.375.066.6
Percentage of Assets30.231.832.132.031.931.631.232.230.326.5
Percentage of Assets aee:UnionElectricCompany57.761.661.159.156.153.952.352.450.749.2

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value2802027307268072554125081246782437623894234792304422810223792199821666214662090620589202982011319647193241900018799183071798617700174241699116726164251620515834156011540816096178331769017535181271787317945178881785317610
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets82.683.383.783.783.684.384.283.783.583.883.883.082.683.182.781.681.581.881.481.481.281.279.578.077.777.376.877.777.577.677.070.770.070.273.775.977.076.676.776.576.776.775.974.3

us-gaap:PropertyPlantAndEquipmentNet dei:LegalEntity

aee:AmerenIllinoisCompany


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1159711358112011086110559102801008398199585934791988969871684638293798777807596746972857121695668486615641662726165603058825731558953695216511750524948486948044770469946574576
Percentage of PropertyPlantAndEquipmentNet41.441.641.842.542.141.741.441.140.840.640.340.139.639.138.638.237.837.437.137.136.936.636.436.135.735.435.435.535.234.934.533.933.433.231.427.727.527.426.326.326.025.6
Percentage of Assets34.234.635.035.635.235.134.834.434.134.033.833.332.732.532.031.230.830.630.230.229.929.729.028.227.727.427.227.627.227.126.624.023.423.323.121.121.221.020.220.119.919.5
Percentage of Assets aee:AmerenIllinoisCompany81.081.382.882.982.582.782.782.281.881.381.381.580.980.880.279.779.479.478.879.279.177.876.976.475.574.273.675.576.275.075.072.270.870.269.468.568.366.266.166.565.161.8

aee:OtherAffiliatedEntitiesAndIntercompanyEliminations


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value17271658150914221166768392164
Percentage of PropertyPlantAndEquipmentNet6.46.86.66.65.84.12.21.0
Percentage of Assets5.45.75.55.54.73.21.70.8
Percentage of Assets aee:OtherAffiliatedEntitiesAndIntercompanyEliminations0.00.00.00.00.00.00.00.0

aee:UnionElectricCompany


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1469014221138791299112844127311263512452123151215912103119331183511768117511153811497114711147811294112421118111183110411101710959108671066010599104991045210337102641015210161100921003899769958979698629775
Percentage of PropertyPlantAndEquipmentNet52.452.151.850.951.251.651.852.152.552.853.153.353.854.354.755.255.856.557.157.558.258.859.560.361.361.962.462.763.463.964.565.365.865.963.156.656.756.954.954.855.054.8
Percentage of Assets43.343.443.342.642.843.543.743.643.844.244.544.344.445.145.345.045.546.246.546.847.247.847.347.147.647.947.948.749.149.649.746.246.146.246.542.943.743.642.141.942.241.6
Percentage of Assets aee:UnionElectricCompany82.483.882.783.783.784.984.683.883.884.684.783.082.283.883.782.082.183.081.881.382.483.280.779.280.380.880.380.980.381.181.078.178.278.977.977.879.279.578.177.578.778.2

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
Value411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411411831
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 Assets1.21.31.31.31.41.41.41.41.51.51.51.51.51.61.61.61.61.71.71.71.71.81.71.81.81.81.81.91.91.92.01.81.81.91.91.71.81.81.71.81.81.81.73.5

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value10279891077993917885876780741744650647626532522538526532538566552573575646649645664724731719698660654665749772776773845843848738754655
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.03.03.43.33.13.03.02.72.62.72.42.42.32.02.02.12.12.12.22.32.32.52.42.82.82.82.93.33.43.43.32.92.93.03.43.33.43.43.63.63.63.23.22.8

us-gaap:OtherAssetsNoncurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value49144253448041940038331129330327525824615914710197959598991141137678797814514411512081838897112117115211214193162
Percentage of OtherAssetsNoncurrent47.844.749.648.345.745.243.739.939.540.742.339.939.329.928.218.818.417.917.717.317.919.919.711.812.012.211.720.019.716.017.212.312.713.213.014.515.114.925.025.422.821.5
Percentage of Assets1.41.31.71.61.41.41.31.11.01.11.01.00.90.60.60.40.40.40.40.40.40.50.50.30.30.30.30.70.70.50.60.40.40.40.40.50.50.50.90.90.80.7
Percentage of Assets aee:AmerenIllinoisCompany3.43.23.93.73.33.23.12.62.52.62.42.32.31.51.41.01.01.01.01.11.11.31.30.90.90.90.91.81.91.51.61.11.11.21.31.51.61.62.93.02.72.2

aee:UnionElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value361375383350352357356370355356306305304293288318317314327335315316321395389387391410416442443443444451449452447441446474489421
Percentage of OtherAssetsNoncurrent35.237.935.635.238.440.340.647.447.947.847.147.148.655.155.259.160.359.060.859.257.155.155.861.159.960.058.956.656.961.563.567.167.967.859.958.557.657.152.856.257.755.8
Percentage of Assets1.11.11.21.11.21.21.21.31.31.31.11.11.11.11.11.21.31.31.31.41.31.41.41.71.71.71.71.91.92.12.12.02.02.12.11.91.91.91.92.02.11.8
Percentage of Assets aee:UnionElectricCompany2.02.22.32.32.32.42.42.52.42.52.12.12.12.12.12.32.32.32.32.42.32.42.32.82.82.92.93.13.23.43.43.33.43.53.43.53.53.53.53.83.93.4

us-gaap:OtherAssetsNoncurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value167145126140
Percentage of OtherAssetsNoncurrent15.516.619.426.8
Percentage of Assets0.50.50.50.5
Percentage of Assets srt:ParentCompany1.51.51.41.7

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi dei:LegalEntity, us-gaap:FinancialInstrument

us-gaap:EquitySecuritiesFvNi

aee:UnionElectricCompany, us-gaap:EquitySecurities


Equity
Period End2020-12-312019-12-31
Value680569
Percentage of EquitySecuritiesFvNi100.0100.0
Percentage of Assets2.12.0
Percentage of Assets aee:UnionElectricCompany us-gaap:EquitySecurities0.00.0

Accounts Payable And Accrued Liabilities Current

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent


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
Value779581958640616544874598593522817591565497902548522460805513499429777525486434711466575559806414428341625458479366693410482401651694
Percentage of AccountsPayableAndAccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.31.83.02.12.11.93.02.12.11.93.02.22.11.93.52.12.11.93.32.12.11.83.32.22.11.93.12.12.72.63.81.81.91.62.91.92.11.62.91.82.11.72.82.9

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value314255363318293246299247272242302275291243337247236198264214212180249251229193207212209230243189184151146148171115133135185182
Percentage of AccountsPayableAndAccruedLiabilitiesCurrent40.343.937.949.747.645.234.241.345.946.437.046.551.548.937.445.145.243.032.841.742.542.032.047.847.144.529.145.536.341.130.145.743.044.323.432.335.731.419.232.938.428.0
Percentage of Assets0.90.81.11.01.00.81.00.91.00.91.11.01.10.91.31.00.90.81.10.90.90.81.11.11.00.80.91.01.01.11.20.80.80.70.70.60.70.50.60.60.80.8
Percentage of Assets aee:AmerenIllinoisCompany2.21.82.72.42.32.02.52.12.32.12.72.52.72.33.32.52.42.12.82.32.42.02.82.92.72.32.52.72.73.03.32.52.52.12.02.02.41.61.81.92.62.5

aee:UnionElectricCompany


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value403267501256246238465261240224428246226203475226208191444209204174417187183182405189195183387186198153345187168142414160179326
Percentage of AccountsPayableAndAccruedLiabilitiesCurrent51.746.052.340.039.943.853.243.640.542.952.441.640.040.852.741.239.841.555.240.740.940.653.735.637.741.957.040.633.932.748.044.946.344.955.240.835.138.859.739.037.150.1
Percentage of Assets1.20.81.60.80.80.81.60.90.90.81.60.90.80.81.80.90.80.81.80.90.90.71.80.80.80.81.80.90.90.91.80.80.90.71.60.80.70.61.80.70.81.4
Percentage of Assets aee:UnionElectricCompany2.31.63.01.61.61.63.11.81.61.63.01.71.61.43.41.61.51.43.21.51.51.33.01.31.31.33.01.41.51.43.01.41.51.22.61.41.31.13.21.31.42.6

Contract With Customer Liability Current

us-gaap:ContractWithCustomerLiabilityCurrent

us-gaap:ContractWithCustomerLiabilityCurrent


Contract
Period End2020-09-302020-06-302019-12-312019-03-312018-12-312018-09-302017-12-31
Value109126111111116126108
Percentage of ContractWithCustomerLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.40.40.40.40.50.4

us-gaap:ContractWithCustomerLiabilityCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value69707480948077717173768469
Percentage of ContractWithCustomerLiabilityCurrent0.00.00.073.474.60.069.40.00.065.865.566.763.9
Percentage of Assets0.20.20.20.30.30.30.30.20.30.30.30.30.3
Percentage of Assets aee:AmerenIllinoisCompany0.50.50.50.60.70.60.60.60.60.60.70.80.7

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
Value21772307218021052000236725052285275223922687258027113345294025812765276226742291243018392093248925562520224921192312272524613228328625771698154616031614178518481727183718881711
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 Assets6.47.06.86.96.78.18.78.09.88.79.99.610.212.811.310.110.911.110.89.510.27.98.910.611.011.09.99.710.712.911.714.414.811.77.86.67.07.07.57.97.47.98.07.2

us-gaap:LiabilitiesCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value847109881696479680784497689780379611821057137513581266121196297181174271375285475766070085477910027718478237927976827648208587538381015
Percentage of LiabilitiesCurrent38.947.637.445.839.834.133.742.732.633.629.645.839.041.146.249.143.834.836.335.430.538.835.934.329.626.231.140.333.736.831.326.225.030.746.944.147.750.848.140.748.553.8
Percentage of Assets2.53.32.53.22.72.82.93.43.22.92.94.44.05.35.24.94.83.93.93.43.13.03.23.63.32.93.13.93.64.73.73.83.73.63.72.93.33.63.63.23.64.3
Percentage of Assets aee:AmerenIllinoisCompany5.97.96.07.46.26.56.98.27.77.07.010.79.813.113.112.612.410.110.28.88.28.08.49.98.97.88.410.710.113.110.311.411.210.910.99.410.711.311.910.711.713.7

aee:UnionElectricCompany


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value9208258337518877941126125512429851402103512211495116410569149641162107110936659779849361088903781946116710471069951656799795830778942745624700
Percentage of LiabilitiesCurrent42.335.838.235.744.433.545.054.945.141.252.240.145.044.739.640.933.134.943.546.745.036.246.739.536.643.240.236.940.942.842.533.128.925.547.151.451.848.252.840.336.137.1
Percentage of Assets2.72.52.62.53.02.73.94.44.43.65.23.84.65.74.54.13.63.94.74.44.62.84.14.24.04.84.03.64.45.55.04.84.33.03.73.43.63.44.03.22.73.0
Percentage of Assets aee:UnionElectricCompany5.24.95.04.85.85.37.58.48.56.99.87.28.510.68.37.56.57.08.37.78.04.97.17.16.88.06.75.97.29.08.18.17.25.16.16.16.56.27.45.95.05.6

us-gaap:LiabilitiesCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilities
Period End2020-12-312019-12-312018-12-312017-12-31
Value565589538444
Percentage of LiabilitiesCurrent25.923.520.015.1
Percentage of Assets1.82.02.01.7
Percentage of Assets srt:ParentCompany5.06.26.05.3

Long Term Debt Current

us-gaap:LongTermDebtCurrent

us-gaap:LongTermDebtCurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value8.08.08.035735735744233633633658064984711708417775786816814314311353953953953801201191196485348848843553552061791791791785.0155155204
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.01.21.21.21.51.21.21.22.12.43.24.53.23.02.32.72.81.81.80.61.71.71.71.70.50.50.63.12.53.94.01.61.60.90.80.80.80.80.00.70.70.9

us-gaap:LongTermDebtCurrent dei:LegalEntity

aee:UnionElectricCompany


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value8.08.08.07.07.07.0923363363365803365347133843831854314314314316.02662662663801201191192231093093092052052051781781781785.0-5.0-4.0
Percentage of LongTermDebtCurrent100.0100.0100.02.02.02.020.8100.0100.0100.0100.051.863.060.945.749.332.063.363.3100.0100.04.467.367.367.3100.0100.0100.0100.034.420.435.035.057.757.799.599.499.499.4100.0100.0-3.2-2.0
Percentage of Assets0.00.00.00.00.00.00.31.21.21.22.11.22.02.71.51.50.71.71.71.81.80.01.11.11.11.70.50.50.61.10.51.41.40.90.90.90.80.80.80.80.0-0.0-0.0
Percentage of Assets aee:UnionElectricCompany0.00.00.00.00.00.00.62.32.32.34.12.33.75.12.72.71.33.13.13.13.20.01.91.91.92.80.90.90.91.70.82.32.41.61.61.61.41.41.41.40.0-0.00.0

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value414392489432374662585522668301282317298285326318298280248252270305379404413437434350350344194190178163188193221237207251262294283337
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 Assets1.21.21.51.41.22.32.01.82.41.11.01.21.11.11.31.21.21.11.01.01.11.31.61.71.81.91.91.61.61.60.90.80.80.70.90.81.01.00.91.11.11.31.21.4

us-gaap:OtherLiabilitiesCurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value2052072212342091952071761841291301611501411771531288894998882114908010012414812115311411479639262865792587790
Percentage of OtherLiabilitiesCurrent49.552.845.254.255.929.535.433.727.542.946.150.850.349.554.348.143.031.437.939.332.626.930.122.319.422.928.642.334.644.558.860.044.438.748.932.138.924.144.423.129.431.8
Percentage of Assets0.60.60.70.80.70.70.70.60.70.50.50.60.60.50.70.60.50.40.40.40.40.40.50.40.30.40.50.70.60.70.50.50.40.30.40.30.40.20.40.20.30.4
Percentage of Assets aee:AmerenIllinoisCompany1.41.51.61.81.61.61.71.51.61.11.11.51.41.31.71.51.30.91.01.11.00.91.31.00.91.21.51.91.62.01.51.51.10.91.30.91.20.81.30.81.11.2

aee:UnionElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value16111697102120128221240210128123115107991031181301281231161391321201161241141179910187829790867711413012084829089
Percentage of OtherLiabilitiesCurrent38.929.619.823.632.119.337.846.031.442.543.636.335.934.731.637.143.645.749.646.051.543.331.728.730.026.127.028.328.925.342.351.150.652.841.059.158.850.640.632.734.431.4
Percentage of Assets0.50.40.30.30.40.40.80.80.70.50.50.40.40.40.40.50.50.50.50.50.60.60.50.50.50.50.50.50.50.40.40.40.40.40.40.50.60.50.40.40.40.4
Percentage of Assets aee:UnionElectricCompany0.90.70.60.70.80.91.51.61.40.90.90.80.70.70.70.80.90.90.90.81.01.00.90.80.90.80.90.80.80.70.60.70.70.70.60.91.01.00.70.60.70.7

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

aee:UnionElectricCompany, aee:AssetRetirementObligationBalance


Other
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value53535353232323236.06.06.06.0151515
Percentage of OtherLiabilitiesCurrent12.314.28.09.14.43.47.68.21.92.02.11.84.75.06.0
Percentage of Assets0.20.20.20.20.10.10.10.10.00.00.00.00.10.10.1
Percentage of Assets aee:UnionElectricCompany aee:AssetRetirementObligationBalance0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherLiabilitiesCurrent us-gaap:BalanceSheetLocation

aee:AssetRetirementObligationBalance


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value59596053535353232323236.06.06.06.01515155.0
Percentage of OtherLiabilitiesCurrent14.315.112.312.314.28.09.14.43.47.68.21.92.02.11.84.75.06.01.3
Percentage of Assets0.20.20.20.20.20.20.20.10.10.10.10.00.00.00.00.10.10.10.0
Percentage of Assets aee:AssetRetirementObligationBalance0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherLiabilitiesCurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value34231227
Percentage of OtherLiabilitiesCurrent7.03.94.38.3
Percentage of Assets0.10.10.00.1
Percentage of Assets srt:ParentCompany0.30.20.10.3

Taxes Payable Current

us-gaap:TaxesPayableCurrent

us-gaap:TaxesPayableCurrent


Taxes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312019-09-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value17812882199142371648153154139915215912277461591247743160126794616113289551591239168163141101651611391346354
Percentage of TaxesPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.40.30.70.50.10.60.30.20.60.50.30.20.60.50.30.20.70.50.30.20.70.50.30.20.70.60.40.30.70.60.40.30.70.60.40.30.70.60.60.30.2

us-gaap:TaxesPayableCurrent dei:LegalEntity

aee:UnionElectricCompany


Taxes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value137854216412164241481106227138110643014811363301491136431273151693220015725222028810766281331031137413113476
Percentage of TaxesPayableCurrent77.066.451.282.485.20.064.990.20.076.550.989.679.170.357.793.192.681.865.293.791.183.172.1170.6119.887.369.6124.2118.9283.1400.0181.187.072.541.281.673.0111.9113.881.496.4120.6
Percentage of Assets0.40.30.10.50.40.20.10.50.40.20.10.50.40.20.10.60.40.30.10.60.50.30.11.20.70.30.10.90.71.21.01.30.50.30.10.60.40.50.30.60.60.3
Percentage of Assets aee:UnionElectricCompany0.80.50.31.10.80.40.21.00.70.40.21.00.80.50.21.10.80.50.21.10.80.50.22.01.10.50.21.51.21.91.72.20.80.50.21.00.80.90.61.01.10.6

Long Term Debt

us-gaap:LongTermDebt

us-gaap:LongTermDebt


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value1119094428509799573267331625160486992
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets34.932.631.330.829.731.027.628.732.0

us-gaap:LongTermDebt dei:LegalEntity

aee:AmerenIllinoisCompany


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value398836133330285726072496224618591729
Percentage of LongTermDebt35.638.339.135.735.634.035.930.724.7
Percentage of Assets12.512.512.211.010.610.69.98.87.9
Percentage of Assets aee:AmerenIllinoisCompany29.529.729.427.627.528.026.824.923.7

aee:AmerenparentDomain


Long
Period End2020-12-312019-12-312018-12-31
Value16001150700
Percentage of LongTermDebt14.312.28.2
Percentage of Assets5.04.02.6
Percentage of Assets aee:AmerenparentDomain0.00.00.0

aee:UnionElectricCompany


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value515242294029398840194135400537644013
Percentage of LongTermDebt46.044.847.349.954.956.464.162.257.4
Percentage of Assets16.114.614.815.416.317.517.717.918.4
Percentage of Assets aee:UnionElectricCompany30.728.328.228.428.629.929.629.230.8

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1249211527110781017210171937889158651822282217859761476136766709469226821659765956607660568816880598159815860612058255825522655045274527458036626678166786677667766826854685368537111
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets36.835.234.633.333.932.030.830.329.329.928.928.228.625.927.327.027.026.626.727.427.829.429.125.525.825.627.026.627.024.726.223.623.726.430.328.929.129.228.228.629.329.429.130.0

us-gaap:LongTermDebtNoncurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value439139473946357635763575357532793296329632962801280023732373219621952338233823442343234323422112211222412241194019401692185615771577157715771727165716571657165816581657
Percentage of LongTermDebtNoncurrent35.234.235.635.235.238.140.137.940.140.141.936.836.835.133.531.732.235.435.535.535.534.134.035.335.338.236.633.333.332.433.729.929.927.223.825.524.824.824.824.824.224.2
Percentage of Assets12.912.012.311.711.912.212.411.511.712.012.110.410.59.19.18.68.79.49.59.79.810.09.99.09.19.89.98.99.08.08.87.07.17.27.27.37.27.27.07.17.17.0
Percentage of Assets aee:AmerenIllinoisCompany30.728.229.227.327.928.829.327.428.128.729.125.426.022.722.921.922.424.424.725.526.026.226.324.424.826.526.724.325.122.124.921.221.421.621.723.923.222.823.023.523.222.4

aee:AmerenTransmissionCompanyOfIllinois


Long
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4484484484480.0
Percentage of LongTermDebtNoncurrent4.05.05.76.30.0
Percentage of Assets1.41.51.61.70.0
Percentage of Assets aee:AmerenTransmissionCompanyOfIllinois0.00.00.00.00.0

aee:AmerenparentDomain


Long
Period End2020-12-312019-12-312018-12-312017-12-31
Value1588794697696
Percentage of LongTermDebtNoncurrent14.38.98.99.8
Percentage of Assets5.02.72.62.7
Percentage of Assets aee:AmerenparentDomain0.00.00.00.0

aee:UnionElectricCompany


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value5618509650964561456045604098377937803780341836683668324935773584378135643563356935683845384438693869361938793885388535353648369736973801380138063772377237723777394939494018
Percentage of LongTermDebtNoncurrent45.044.246.044.844.848.646.043.746.046.043.548.248.248.050.451.855.454.054.054.054.055.955.964.764.761.863.466.766.767.666.370.170.165.557.456.156.556.556.556.557.657.656.5
Percentage of Assets16.615.515.914.915.215.614.213.213.513.712.613.613.812.513.814.015.014.414.414.815.016.416.316.516.715.817.117.818.016.717.316.516.617.317.416.216.416.516.016.216.916.817.0
Percentage of Assets aee:UnionElectricCompany31.530.030.429.429.730.427.425.425.726.323.925.525.523.125.525.527.025.825.425.726.128.627.827.828.226.728.629.529.427.328.327.928.229.529.129.429.730.129.629.931.531.60.0

us-gaap:LongTermDebtNoncurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Long
Period End2020-12-312019-12-312018-12-312017-12-31
Value1588794697696
Percentage of LongTermDebtNoncurrent14.38.98.99.8
Percentage of Assets5.02.72.62.7
Percentage of Assets srt:ParentCompany14.28.37.88.2

Long Term Debt And Capital Lease Obligations

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

us-gaap:LongTermDebtAndCapitalLeaseObligations

aee:AmerenIllinoisCompany, us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value43913947394635763576357535753279329632963296311431132830283025902589258825882344234324722471224122412241224119401940169218561727
Percentage of LongTermDebtAndCapitalLeaseObligations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets12.912.012.311.711.912.212.411.511.712.012.111.611.710.910.910.110.310.410.59.79.810.610.59.69.79.89.98.99.08.08.87.9
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value56265104510445684567456741904115411641163998400442023962396139673966399539944000399938514110413541353999399940044004375837574006
Percentage of LongTermDebtAndCapitalLeaseObligations128.1129.3129.3127.7127.7127.7117.2125.5124.9124.9121.3128.6135.0140.0140.0153.2153.2154.4154.3170.6170.7155.8166.3184.5184.5178.4178.4206.4206.4222.1202.4232.0
Percentage of Assets16.615.615.915.015.215.614.514.414.615.014.714.915.815.215.315.515.716.116.216.616.816.517.417.617.917.517.618.318.517.817.918.3
Percentage of Assets aee:UnionElectricCompany us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LongTermDebtAndCapitalLeaseObligations us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value1250011535110861052910528973593578987855885578439826384607936793576997399727872767038703670167275637663766240624059445944587460386157
Percentage of LongTermDebtAndCapitalLeaseObligations284.7292.2280.9294.4294.4272.3261.7274.1259.6259.6256.0265.4271.8280.4280.4297.3285.8281.2281.1300.3300.3283.8294.4284.5284.5278.4278.4306.4306.4347.2325.3356.5
Percentage of Assets36.935.234.634.535.133.332.331.530.531.131.030.731.830.430.630.129.329.329.529.229.630.030.827.227.527.327.527.227.527.828.728.2
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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
Value393837373414397401522539558558529545541545711758768769499537581580666689708705400463480466104211401113117811521251135713449221067105710451165
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 Assets0.10.10.11.21.41.41.41.81.92.02.12.02.02.12.12.83.03.13.12.12.32.52.52.83.03.13.11.82.12.32.24.75.15.15.44.95.45.95.73.94.64.54.44.9

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value686769204225212214261274281280284292285285322350345346262284271271282292278277189215200197376416396406444458499495328446413
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent174.4176.3186.554.754.353.453.450.050.850.450.253.753.652.752.345.346.244.945.052.552.946.646.742.342.439.339.347.246.441.742.336.136.535.634.538.536.636.836.835.641.839.5
Percentage of Assets0.20.20.20.70.70.70.70.91.01.01.01.11.11.11.11.31.41.41.41.11.21.21.11.21.31.21.20.91.00.90.91.71.91.81.91.92.02.22.11.41.91.8
Percentage of Assets aee:AmerenIllinoisCompany0.50.50.51.61.81.71.82.22.32.42.52.62.72.72.83.23.63.63.72.83.23.03.03.33.43.33.32.42.82.62.65.15.65.45.66.16.46.96.94.66.25.6

aee:UnionElectricCompany


Pension
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value313435129141139141211214227228204209212213274287292291183195236234267275277274147172198189423465452461432442498491352371369
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent79.589.594.634.634.135.035.240.439.740.740.938.638.339.239.138.537.938.037.836.736.340.640.340.139.939.138.936.837.141.240.640.640.840.639.137.535.336.736.538.234.835.3
Percentage of Assets0.10.10.10.40.50.50.50.70.80.80.80.80.80.80.81.11.11.21.20.80.81.01.01.11.21.21.20.70.80.90.91.92.12.12.11.81.92.22.11.51.61.6
Percentage of Assets aee:UnionElectricCompany0.20.20.20.80.90.90.91.41.51.61.61.41.51.51.51.92.02.12.11.31.41.81.71.92.02.02.01.11.31.51.53.23.53.53.53.33.54.03.82.83.03.0

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value27374337
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent73.09.27.76.8
Percentage of Assets0.10.10.20.1
Percentage of Assets srt:ParentCompany0.20.40.50.4

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-31
Value37401558531
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.097.4
Percentage of Assets0.11.42.12.0
Percentage of Assets us-gaap:PensionPlansDefinedBenefit0.00.00.00.0

Minority Interest

us-gaap:MinorityInterest

us-gaap:MinorityInterest


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value129129142142142142142142142142142142142142142142142142142142142142142142142142142142142142142151151151151152145147149155155155154155206206204
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.40.40.50.50.50.50.50.50.50.50.50.50.50.50.60.60.60.60.60.60.60.60.60.60.60.60.60.70.70.70.70.70.70.70.60.60.60.60.70.70.70.70.00.00.00.9

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
Value447452466438456482467466464422408409431445460469477481477481490530531530524524514522524554622534585593668563564567447469481553615491
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 Assets1.31.41.51.41.51.61.61.61.71.51.51.51.61.71.81.81.91.91.92.02.12.32.22.32.32.32.32.42.42.63.02.42.62.73.12.42.52.51.92.02.12.42.62.1

us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity

aee:AmerenIllinoisCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value237249251245264277260260238203204207218230234229228236222212207236222224221216189165152173166152149146399276276291183231282460
Percentage of OtherLiabilitiesNoncurrent53.055.153.955.957.957.555.755.851.348.150.050.650.651.750.948.847.849.146.544.142.244.541.842.342.241.236.831.629.031.226.728.525.524.659.749.048.951.340.949.358.674.8
Percentage of Assets0.70.80.80.80.90.90.90.90.80.70.70.80.80.90.90.90.91.00.90.90.91.00.91.01.00.90.80.80.70.80.80.70.70.71.81.21.21.30.81.01.22.0
Percentage of Assets aee:AmerenIllinoisCompany1.71.81.91.92.12.22.12.22.01.81.81.92.02.22.32.32.32.52.32.32.32.62.52.62.62.62.32.12.02.32.22.02.02.05.53.83.94.02.53.33.96.2

aee:UnionElectricCompany


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value71596637385240444440165.07.013121316161921242728303032304442435249150146158161153150149172176218
Percentage of OtherLiabilitiesNoncurrent15.913.114.28.48.310.88.69.49.59.53.91.21.62.92.62.83.43.34.04.44.95.15.35.75.76.15.88.48.07.88.49.225.624.623.728.627.126.533.336.736.635.4
Percentage of Assets0.20.20.20.10.10.20.10.20.20.10.10.00.00.00.00.10.10.10.10.10.10.10.10.10.10.10.10.20.20.20.20.20.70.70.70.70.70.70.60.70.80.9
Percentage of Assets aee:UnionElectricCompany0.40.30.40.20.20.30.30.30.30.30.10.00.00.10.10.10.10.10.10.20.20.20.20.20.20.20.20.30.30.30.40.41.11.11.21.21.21.21.21.41.41.7

us-gaap:OtherLiabilitiesNoncurrent us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value85808287
Percentage of OtherLiabilitiesNoncurrent18.217.120.118.9
Percentage of Assets0.30.30.30.3
Percentage of Assets srt:ParentCompany0.80.80.91.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value935391488938848982278085805980627791770576317656738672307184734571587064710371936922686969467014676467046713677465726513654465746374636566167874755574327919772577307856
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.627.927.927.827.427.627.928.227.728.028.028.427.727.727.728.728.328.528.829.829.129.429.429.929.229.329.631.030.430.831.129.428.629.030.333.532.932.533.533.132.933.1

us-gaap:StockholdersEquity dei:LegalEntity

aee:AmerenIllinoisCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value5258514249664762468543524132402139563894377436103547342533103225317031133034302129382925289728412742271326612602252725002448249324312416240124472434244124522502249325763072
Percentage of StockholdersEquity56.256.255.656.156.953.851.349.950.850.549.547.248.047.446.143.944.344.142.742.042.442.641.740.540.540.539.638.438.538.437.437.938.138.036.331.132.232.831.00.00.033.339.1
Percentage of Assets15.515.715.515.615.614.914.314.114.114.213.913.413.313.112.812.612.612.512.312.512.312.512.312.111.811.911.711.911.711.811.611.110.911.011.010.410.610.710.410.710.711.013.0
Percentage of Assets aee:AmerenIllinoisCompany36.736.836.736.436.635.033.933.733.733.933.332.832.932.732.032.232.332.532.032.832.632.732.532.832.332.131.832.632.732.732.833.533.033.233.033.934.233.634.035.434.834.80.0

aee:UnionElectricCompany


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value5551537052104788449143394349442542754268422943564237406940814117404340354090414739793956408241183954399440524121401139633993409639984004405441374001395840374235413041534057
Percentage of StockholdersEquity59.358.758.356.454.653.754.054.954.955.455.456.957.456.356.856.156.557.157.657.757.557.658.858.758.559.660.460.861.060.861.062.362.762.961.352.553.053.351.00.00.053.751.6
Percentage of Assets16.416.416.315.715.014.815.015.515.215.515.516.215.915.615.716.116.016.316.617.216.716.917.317.617.117.517.918.818.618.719.018.317.918.218.617.617.417.317.118.117.717.717.1
Percentage of Assets aee:UnionElectricCompany31.131.631.030.829.328.929.129.829.129.729.630.329.429.029.129.328.929.229.129.929.229.429.529.528.829.529.931.330.430.630.931.030.431.131.131.931.631.531.633.533.033.20.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:Parent


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value9353914889388489822780858059806277917705763176567386723071847103694667136544661679197730
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.627.927.927.827.427.627.928.227.728.028.028.427.727.727.728.829.429.631.130.333.532.9
Percentage of Assets us-gaap:Parent0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value948292779080863183698227820182047933784777737798752873727326748773007206724573357064701170887156690668466855691667146655668667256525651667678026770075798068815279437880788480607179
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.028.328.328.327.928.128.328.728.228.528.628.928.328.328.229.228.929.029.330.429.730.030.030.529.829.930.231.631.131.431.830.029.329.731.034.233.533.134.134.934.033.833.534.00.0

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

aee:AmerenIllinoisCompany, aee:PreferredStockNotSubjectToMandatoryRedemption


Stockholders
Period End2020-12-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value626262626262626262626262626262115115
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest0.70.80.80.80.80.80.80.80.90.90.90.90.90.80.81.41.6
Percentage of Assets0.20.20.20.20.20.20.20.20.30.30.30.30.30.30.30.50.0
Percentage of Assets aee:AmerenIllinoisCompany aee:PreferredStockNotSubjectToMandatoryRedemption0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value272226922652253825382288218821732173217321732093209320332013200520051980196519651965195222231951
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest28.729.029.229.430.327.826.726.527.427.728.026.827.827.627.527.728.328.929.429.024.424.827.627.2
Percentage of Assets8.08.28.38.38.57.87.67.67.77.98.07.87.97.87.88.18.58.79.39.08.38.39.40.0
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:PreferredStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-30
Value4949626262626262626262
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest0.50.50.70.70.70.80.80.80.80.80.8
Percentage of Assets0.10.10.20.20.20.20.20.20.20.20.2
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value248724012252216220852002188217861721165915391455139213301235967825611410360408542709566
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest26.225.924.825.024.924.322.921.821.721.119.818.718.518.016.913.311.68.96.15.35.16.98.87.9
Percentage of Assets7.37.37.07.16.96.86.56.36.16.05.75.45.25.14.83.93.52.71.91.61.72.33.00.0
Percentage of Assets aee:AmerenIllinoisCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, aee:PreferredStockNotSubjectToMandatoryRedemption


Stockholders
Period End2020-12-312019-12-312019-06-302019-03-312018-12-312018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value808080808080808080808080808080113113
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest0.91.01.01.01.01.11.11.11.11.11.21.21.21.01.01.41.6
Percentage of Assets0.20.30.30.30.30.30.30.30.30.30.40.40.40.30.30.50.0
Percentage of Assets aee:UnionElectricCompany aee:PreferredStockNotSubjectToMandatoryRedemption0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value270126312518202720272027202719031903190319031858185818581858182818221569156015561555155515551119
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest28.528.427.723.524.224.624.723.224.024.324.523.824.725.225.425.225.722.923.323.019.319.719.315.6
Percentage of Assets8.08.07.96.66.86.97.06.76.86.97.06.97.07.17.27.47.76.97.47.16.66.66.60.0
Percentage of Assets aee:UnionElectricCompany us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value225921482101217018731721173119311781177417351907178816201632167116691892184219071891200718781794
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest23.823.223.125.122.420.921.123.522.522.622.324.523.822.022.323.123.527.627.628.223.425.523.325.0
Percentage of Assets6.76.66.67.16.25.96.06.86.36.46.47.16.76.26.36.87.18.38.88.78.08.57.90.0
Percentage of Assets aee:UnionElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:ConsolidatedEntities

srt:ParentCompany


Stockholders
Period End2020-12-312019-12-312018-12-312017-12-31
Value8938805976317184
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest98.498.398.298.1
Percentage of Assets27.927.928.027.7
Percentage of Assets srt:ParentCompany79.884.384.985.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

aee:DeferredRetirementBenefitCosts


Stockholders
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-1.0-1.0-15.0-16.0-16.0-17.0-21.0-21.0-21.0-22.0-17.0-19.0-17.0-18.0-23.0-3.0-9.03.0-33.0-57.0-17.0-23.0-43.025
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-0.0-0.0-0.2-0.2-0.2-0.2-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.2-0.3-0.0-0.10.0-0.5-0.7-0.2-0.3-0.60.0
Percentage of Assets-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.0-0.00.0-0.2-0.2-0.1-0.10.00.0
Percentage of Assets aee:DeferredRetirementBenefitCosts0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-1.0-1.0-15.0-16.0-16.0-17.0-21.0-21.0-21.0-22.0-17.0-19.0-17.0-18.0-23.0-3.0-9.03.0-8.0-50.0-17.0-13.05.0
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest-0.0-0.0-0.2-0.2-0.2-0.2-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.2-0.3-0.0-0.10.0-0.1-0.6-0.2-0.20.1
Percentage of Assets-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.0-0.00.0-0.0-0.2-0.1-0.10.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value6436629561795733571656955694567356495625562755985576554655405556561656175632561655985520541247804604
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest67.967.968.166.468.369.269.469.171.271.772.471.874.175.275.676.779.281.984.283.069.470.067.166.60.0
Percentage of Assets19.019.219.318.819.019.519.719.920.120.420.720.820.921.321.422.523.824.826.825.723.723.522.80.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value3.03.03.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.0
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NoncontrollingInterest


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value129129142142142142142142142142142142142142142142142142142151149154204211218
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest1.41.41.61.61.71.71.71.71.81.81.81.81.91.91.92.02.02.12.12.21.82.02.52.90.0
Percentage of Assets0.40.40.40.50.50.50.50.50.50.50.50.50.50.50.50.60.60.60.70.70.60.70.90.00.0
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value291528502757276925252404238024082161209920242073182716991660156813311103907100623692225245521812110
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest30.730.730.432.130.229.229.029.427.226.726.026.624.323.022.721.618.816.113.614.929.428.230.530.40.0
Percentage of Assets8.68.78.69.18.48.28.28.47.77.67.47.76.96.56.46.35.64.94.34.610.09.510.40.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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
Value3.03.03.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-31
Value3.02.0
Percentage of CommonStockValue100.0100.0
Percentage of Assets0.00.0
Percentage of Assets srt:ParentCompany0.00.0

Additional Paid In Capital

us-gaap:AdditionalPaidInCapital

us-gaap:AdditionalPaidInCapital


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value64366295617957335716569556945673564956255627559855765546554055345528552255565550554555395616561256065600561756125607560256325624561956145616561156005596559855805559554055205412
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets19.019.219.318.819.019.519.719.920.120.420.720.820.921.321.421.621.922.322.523.023.323.723.823.924.224.524.825.726.026.526.825.125.225.625.723.924.424.423.723.923.823.723.522.8

us-gaap:AdditionalPaidInCapital dei:LegalEntity

aee:AmerenIllinoisCompany


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value272226922652253825382288218821732173217321732093209320332013200520052005200520052005200520051980198019801980196519651965196519651965196519651965196519651965195219521952
Percentage of AdditionalPaidInCapital42.342.842.944.344.440.238.438.338.538.638.637.437.536.736.336.236.336.336.136.136.236.235.735.335.335.435.335.035.035.134.934.935.035.035.035.035.135.135.135.035.135.4
Percentage of Assets8.08.28.38.38.57.87.67.67.77.98.07.87.97.87.87.87.98.18.18.38.48.68.58.48.68.78.79.09.19.39.38.88.89.09.08.48.68.68.38.48.38.3
Percentage of Assets aee:AmerenIllinoisCompany19.019.319.619.419.818.418.018.218.518.919.219.019.419.419.520.020.521.021.221.822.322.422.522.923.323.423.624.625.525.726.426.426.727.027.027.227.627.127.227.627.326.4

aee:UnionElectricCompany


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value270126312518202720272027202719031903190319031858185818581858182818281828182818241822182218221784178417841569156015601560156015561556155615561555155515551555155515551555
Percentage of AdditionalPaidInCapital42.041.840.835.435.535.635.633.533.733.833.833.233.333.533.533.033.133.132.932.932.932.932.431.831.831.927.927.827.827.827.727.727.727.727.727.727.827.827.827.928.028.2
Percentage of Assets8.08.07.96.66.86.97.06.76.86.97.06.97.07.17.27.17.27.47.47.67.77.87.77.67.77.86.97.17.27.47.47.07.07.17.16.66.86.86.66.76.66.6
Percentage of Assets aee:UnionElectricCompany15.215.515.013.113.213.513.612.812.913.213.312.912.913.213.213.013.113.213.013.113.313.613.212.813.013.211.611.811.812.012.111.811.812.111.912.012.312.412.212.312.412.4

us-gaap:AdditionalPaidInCapital us-gaap:ConsolidatedEntities

srt:ParentCompany


Additional
Period End2020-12-312019-12-31
Value61795694
Percentage of AdditionalPaidInCapital100.0100.0
Percentage of Assets19.319.7
Percentage of Assets srt:ParentCompany55.259.6

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
Value29152850275727692525240423802408216120992024207318271699166018301649156315681643137613331331140511611111110311549579069079677627641006225919831869236924402248220322252455
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 Assets8.68.78.69.18.48.28.28.47.77.67.47.76.96.56.47.16.56.36.36.85.85.75.66.05.04.94.95.34.44.34.34.33.43.54.69.68.68.210.010.49.69.49.510.4

us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity

aee:AmerenIllinoisCompany


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value248724012252216220852002188217861721165915391455139213301235115811031046967952868854825793694664611566491463410454392376360406392398408471461542
Percentage of RetainedEarningsAccumulatedDeficit85.384.281.778.182.683.379.174.279.679.076.070.276.278.374.463.366.966.961.757.963.164.162.056.459.859.855.449.051.351.145.246.951.449.235.818.019.821.317.219.320.524.4
Percentage of Assets7.37.37.07.16.96.86.56.36.16.05.75.45.25.14.84.54.44.23.93.93.63.73.53.43.02.92.72.62.32.21.92.01.81.71.61.71.71.71.72.02.02.3
Percentage of Assets aee:AmerenIllinoisCompany17.417.216.616.516.316.115.415.014.714.413.613.212.912.711.911.611.310.910.210.39.69.59.39.28.27.97.37.16.46.15.56.15.35.24.95.65.55.55.76.76.47.3

aee:UnionElectricCompany


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value225921482101217018731721173119311781177417351907178816201632169816241616167117321566154316691743157916191892197018601812184219491851185719071991185518121891208919842007
Percentage of RetainedEarningsAccumulatedDeficit77.575.476.278.474.271.672.780.282.484.585.792.097.995.498.392.898.5103.4106.6105.4113.8115.8125.4124.1136.0145.7171.5170.7194.4200.0203.1201.6242.9243.1189.688.193.597.079.885.688.390.2
Percentage of Assets6.76.66.67.16.25.96.06.86.36.46.47.16.76.26.36.66.46.56.87.26.66.67.17.46.87.18.39.08.68.68.88.78.38.58.78.58.17.98.08.98.58.5
Percentage of Assets aee:UnionElectricCompany12.712.712.514.012.211.511.613.012.112.312.113.312.411.511.612.111.611.711.912.511.511.512.012.511.511.914.014.914.114.014.314.714.114.414.615.414.614.414.816.515.816.1

us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:ConsolidatedEntities

srt:ParentCompany


Retained
Period End2020-12-312019-12-312018-12-312017-12-31
Value2757238020241660
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0
Percentage of Assets8.68.27.46.4
Percentage of Assets srt:ParentCompany24.624.922.519.6

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value-1.0-1.0-15.0-16.0-16.0-17.0-21.0-21.0-21.0-22.0-17.0-19.0-17.0-18.0-21.0-21.0-23.0-23.0-2.0-1.0-5.0-3.0-5.0-5.0-9.0-9.06.06.03.03.0-19.0-9.0-15.0-8.02.0-30.0-35.0-50.0-25.0-21.0-20.0-17.0-13.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.0-0.0-0.0-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.1-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.0-0.1-0.0-0.1-0.00.0-0.1-0.2-0.2-0.1-0.1-0.1-0.1-0.1

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities

srt:ParentCompany


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value-1.0-17.0-22.0-18.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0
Percentage of Assets-0.0-0.1-0.1-0.1
Percentage of Assets srt:ParentCompany-0.0-0.2-0.2-0.2

Minority Interest

us-gaap:MinorityInterest

us-gaap:MinorityInterest


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-31
Value129129142142142142142142142142142142142142142142142142142142142142142142142142142142142142142151151151151152145147149155155155154155206206204
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.40.40.50.50.50.50.50.50.50.50.50.50.50.50.60.60.60.60.60.60.60.60.60.60.60.60.60.70.70.70.70.70.70.70.60.60.60.60.70.70.70.70.00.00.00.9

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:AdditionalPaidInCapital


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value121121410.014131417181918162317
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value8.0-9.08.07.07.0-12.07.07.06.0-21.0116.07.0-11.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Minority Interest Decrease From Distributions To Noncontrolling Interest Holders

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders us-gaap:StatementEquityComponents

us-gaap:MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders

us-gaap:NoncontrollingInterest


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1.02.01.02.01.02.01.02.01.02.01.02.01.02.0
Percentage of MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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
Value471-35.0398635404290502789492387484866562258461780532331564796414349489761469298348549415239379546389379329556413392312663349554346725391380
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 RevenueFromContractWithCustomerIncludingAssessedTax32.0-2.230.039.028.920.138.147.635.724.934.150.236.016.332.945.334.621.941.642.829.024.337.441.533.519.225.432.929.215.028.733.327.725.721.827.824.923.619.829.219.629.120.332.022.719.6

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value27313164175108232256254225227143229157130187253163212176245153229222155132254499510919214481155271788171289663390315134127
Percentage of NetCashProvidedByUsedInOperatingActivities58.0-37.141.227.626.780.051.032.245.758.729.526.427.950.440.632.430.664.031.230.837.065.645.420.428.185.214.117.326.380.338.014.839.871.523.714.617.273.721.25.025.856.938.717.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.50.812.310.77.716.119.515.316.314.610.113.310.08.213.314.710.614.013.013.210.716.017.08.59.416.33.65.77.712.010.94.911.018.45.24.04.317.44.21.55.116.57.95.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany43.41.60.029.719.032.139.145.041.129.821.240.627.217.127.744.128.330.229.636.228.233.840.123.725.734.17.716.621.024.825.514.830.039.613.212.512.639.910.84.414.439.00.017.0

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value275-51.0202417251412274792091522995493367619742330393281524195169207594289157290448116963624432706825642120612120250127380191491
Percentage of NetCashProvidedByUsedInOperatingActivities58.4145.750.865.762.114.145.260.742.539.361.863.459.829.542.754.257.028.149.865.847.148.442.378.161.652.783.381.628.040.295.581.169.417.977.875.749.930.964.775.678.214.455.267.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.7-3.315.225.618.02.817.228.915.29.821.131.821.54.814.124.619.76.120.728.213.711.815.832.420.610.121.226.88.26.027.427.019.24.617.021.012.47.312.822.115.34.211.221.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany34.0-7.20.041.731.76.036.145.226.220.141.948.635.29.628.237.932.411.837.545.022.522.827.550.732.719.639.240.812.911.847.440.530.48.538.039.624.417.530.044.933.210.40.046.3

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-871.0-889.0-1348.0-666.0-631.0-684.0-637.0-644.0-587.0-567.0-617.0-590.0-532.0-597.0-620.0-526.0-520.0-539.0-590.0-516.0-525.0-510.0-614.0-487.0-436.0-439.0-505.0-442.0-457.0-313.0-690.0-396.0-334.0-303.0-299.0-373.0-312.0-326.0-291.0-259.0-248.0-250.0-336.0-216.0-243.0-317.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-59.2-56.8-101.5-40.9-45.1-47.5-48.4-38.8-42.6-36.4-43.5-34.2-34.0-37.7-44.2-30.5-33.8-35.6-43.5-27.8-36.8-35.6-46.9-26.6-31.1-28.2-36.9-26.5-32.2-19.6-52.2-24.2-23.8-20.5-19.8-18.6-18.8-19.7-18.4-11.4-13.9-13.1-19.7-9.5-14.1-16.3

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-331.0-337.0-414.0-371.0-336.0-323.0-302.0-345.0-291.0-267.0-311.0-338.0-299.0-300.0-316.0-274.0-253.0-227.0-239.0-241.0-169.0-269.0-298.0-240.0-168.0-207.0-201.0-195.0-218.0-214.0-239.0-177.0-141.0-138.0-133.0-57.0-161.0-86.0-84.0-87.0-106.0-19.0-64.0-72.0
Percentage of NetCashProvidedByUsedInInvestingActivities38.037.930.755.753.247.247.453.649.647.150.457.356.250.351.052.148.742.140.546.732.252.748.549.338.547.239.844.147.768.434.644.742.245.544.515.351.626.428.933.642.77.619.033.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-22.5-21.5-31.2-22.8-24.0-22.4-22.9-20.8-21.1-17.2-21.9-19.6-19.1-18.9-22.5-15.9-16.5-15.0-17.6-13.0-11.8-18.8-22.8-13.1-12.0-13.3-14.7-11.7-15.4-13.4-18.1-10.8-10.0-9.4-8.8-2.8-9.7-5.2-5.3-3.8-6.0-1.0-3.8-3.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany-52.6-40.90.0-63.0-59.3-44.7-46.2-61.2-53.2-35.0-46.1-59.9-51.7-39.5-46.9-47.7-43.9-32.3-40.2-35.7-31.2-39.7-53.9-36.6-32.7-27.8-31.8-34.1-42.0-27.6-42.4-32.4-27.3-20.2-22.6-8.8-28.5-11.9-13.7-11.7-17.0-2.40.0-9.7

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-655.0-398.0-1027.0-273.0-276.0-328.0-310.0-264.0-257.0-264.0-241.0-192.0-278.0-265.0-230.0-202.0-185.0-68.0-210.0-370.0-184.0-170.015-411.0-159.0-169.0-244.0-180.0-209.0-204.0-181.0-221.0-156.0-129.0-133.0-177.0-175.0-218.0-168.0-139.0-164.0-156.0-219.0-130.0
Percentage of NetCashProvidedByUsedInInvestingActivities75.244.876.241.043.748.048.741.043.846.639.132.552.344.437.138.435.612.635.671.735.033.3-2.484.436.538.548.340.745.765.226.255.846.742.644.547.556.166.957.753.766.162.465.260.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-44.5-25.4-77.3-16.8-19.7-22.8-23.6-15.9-18.6-17.0-17.0-11.1-17.8-16.7-16.4-11.7-12.0-4.5-15.5-19.9-12.9-11.91.1-22.4-11.3-10.9-17.8-10.8-14.7-12.8-13.7-13.5-11.1-8.7-8.8-8.8-10.5-13.1-10.6-6.1-9.2-8.2-12.8-5.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany-81.0-56.50.0-27.3-34.8-48.2-49.4-24.9-32.2-34.8-33.8-17.0-29.1-33.5-32.9-18.1-19.8-8.6-28.0-31.8-21.2-22.92.0-35.1-18.0-21.1-33.0-16.4-23.2-25.0-23.7-20.2-17.5-16.2-19.8-16.6-20.7-31.5-24.9-12.5-20.0-20.20.0-12.3

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
Value495795108336187421156-112.099191148-280.0-23.0360160-255.0-10.020717-275.0111-118.0345-204.0-37.0142149-140.06270147-131.0-66.0-99.0-119.0-2.0-192.0-113.0-288.0-260.0-296.0-276.0-73.0-407.0-2.0-325.0
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax33.650.881.62.213.429.211.9-6.87.212.310.4-16.2-1.522.711.4-14.8-0.713.71.3-14.87.8-8.226.4-11.1-2.69.110.9-8.44.44.411.1-8.0-4.7-6.7-7.9-0.1-11.6-6.8-18.3-11.5-16.6-14.5-4.3-18.0-0.1-16.8

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value15132625020123010654109725317712314718112921901560-1.016-31.01478536-48.0152991102295-1.0-9.0-40.0-38.09.0-37.0-37.0-77.0-83.0-239.0-110.0-33.0-153.0
Percentage of NetCashProvidedByUsedInFinancingActivities30.541.023.1558.3123.025.234.6-97.372.727.7119.6-43.9-639.150.380.6-8.2-900.07.2352.90.414.426.342.6-41.7-97.3-33.8102.0-70.7177.431.464.60.813.640.431.9-450.019.332.726.731.980.739.945.237.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.320.818.812.316.57.44.16.65.23.412.57.19.411.49.21.25.91.04.4-0.11.1-2.211.24.62.6-3.111.15.97.81.47.2-0.1-0.6-2.7-2.50.4-2.2-2.2-4.9-3.7-13.4-5.8-1.9-6.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany24.039.60.034.140.614.78.319.313.27.026.321.825.423.819.13.715.62.110.1-0.13.0-4.626.613.07.0-6.424.017.321.22.816.8-0.2-1.7-5.8-6.51.4-6.6-5.1-12.6-11.1-38.4-13.60.0-20.5

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value385316960-145.012272108-214.049116-57.0-375.0-43.019233-221.0-118.0-25.0-72.0-153.0-11.0-198.0-92.0-114.0-131.012-46.0-295.0121107-280.0-141.0-96.0-86.0-107.0-112.0-34.0-101.0-189.0-85.0-68.0-88.0-61.0-161.0
Percentage of NetCashProvidedByUsedInFinancingActivities77.839.788.6-402.86.464.669.2191.149.560.7-38.5133.9187.053.320.686.71180.0-12.1-423.555.6-9.9167.8-26.755.9354.18.5-30.9210.7195.2152.9-190.5107.6145.586.989.95600.017.789.465.632.723.031.983.639.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax26.220.272.3-8.90.918.98.2-12.93.67.5-4.0-21.8-2.812.12.4-12.8-7.7-1.7-5.3-8.2-0.8-13.8-7.0-6.2-9.40.8-3.4-17.78.56.7-21.2-8.6-6.8-5.8-7.1-5.6-2.0-6.1-12.0-3.7-3.8-4.6-3.6-7.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany47.644.90.0-14.51.540.017.2-20.26.115.3-8.0-33.2-4.524.24.7-19.8-12.6-3.2-9.6-13.1-1.3-26.7-12.2-9.7-14.81.5-6.2-26.913.413.1-36.7-12.9-10.8-10.8-15.9-10.5-4.0-14.6-28.0-7.6-8.3-11.40.0-15.2

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value95-129.05.0-40.027
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.5-8.20.3-2.91.9

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect dei:LegalEntity

aee:AmerenIllinoisCompany


Cash
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value932.05.02.015
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect97.9-1.6100.0-5.055.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.30.10.30.11.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany14.80.20.80.42.1

aee:UnionElectricCompany


Cash
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value5.0-133.0-1.0-13.0-15.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect5.3103.1-20.032.5-55.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.3-8.5-0.1-0.9-1.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany0.6-18.9-0.1-1.6-2.2

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
Value59-54.0-36.04242-23.06.05431-81.0-43.05022-68.0-37.03446-60.0-24.03632-55.0-9.04850-75.0-37.06967-102.0-53.07050-127.0-49.07153-80.0-7.08980-135.0-39.06940-148.0
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInventories dei:LegalEntity

aee:AmerenIllinoisCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value27-30.0-13.04128-41.0-9.03524-52.0-15.04525-63.0-16.03729-49.0-23.04025-57.0-22.04541-89.0-33.07352-88.0-35.07055-105.0-26.06544-103.0-20.09470-123.0-40.091
Percentage of IncreaseDecreaseInInventories45.855.636.197.666.7178.3-150.064.877.464.234.990.0113.692.643.2108.863.081.795.8111.178.1103.6244.493.882.0118.789.2105.877.686.366.0100.0110.082.753.191.583.0128.8285.7105.687.591.1102.6131.9

aee:UnionElectricCompany


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value32-24.0-22.01.0141816197.0-29.0-27.05.0-3.0-5.0-21.0-4.018-11.0-1.0-4.07.02.0132.010.014-5.0-3.014-14.0-18.01.0-6.0-22.0-5.010.017269.0-4.016-14.03.012
Percentage of IncreaseDecreaseInInventories54.244.461.12.433.3-78.3266.735.222.635.862.810.0-13.67.456.8-11.839.118.34.2-11.121.9-3.6-144.44.220.0-18.713.5-4.320.913.734.01.4-12.017.310.214.132.1-32.5-128.6-4.520.010.4-7.717.4

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value471-35.0398635404290502789492387484866562258461780532331564796414349489761469298348549415239379546389379329556413392312663349554346725391380
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 RevenueFromContractWithCustomerIncludingAssessedTax32.0-2.230.039.028.920.138.147.635.724.934.150.236.016.332.945.334.621.941.642.829.024.337.441.533.519.225.432.929.215.028.733.327.725.721.827.824.923.619.829.219.629.120.332.022.719.6

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value27313164175108232256254225227143229157130187253163212176245153229222155132254499510919214481155271788171289663390315134127
Percentage of NetCashProvidedByUsedInOperatingActivities58.0-37.141.227.626.780.051.032.245.758.729.526.427.950.440.632.430.664.031.230.837.065.645.420.428.185.214.117.326.380.338.014.839.871.523.714.617.273.721.25.025.856.938.717.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.50.812.310.77.716.119.515.316.314.610.113.310.08.213.314.710.614.013.013.210.716.017.08.59.416.33.65.77.712.010.94.911.018.45.24.04.317.44.21.55.116.57.95.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany43.41.60.029.719.032.139.145.041.129.821.240.627.217.127.744.128.330.229.636.228.233.840.123.725.734.17.716.621.024.825.514.830.039.613.212.512.639.910.84.414.439.00.017.0

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value275-51.0202417251412274792091522995493367619742330393281524195169207594289157290448116963624432706825642120612120250127380191491
Percentage of NetCashProvidedByUsedInOperatingActivities58.4145.750.865.762.114.145.260.742.539.361.863.459.829.542.754.257.028.149.865.847.148.442.378.161.652.783.381.628.040.295.581.169.417.977.875.749.930.964.775.678.214.455.267.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.7-3.315.225.618.02.817.228.915.29.821.131.821.54.814.124.619.76.120.728.213.711.815.832.420.610.121.226.88.26.027.427.019.24.617.021.012.47.312.822.115.34.211.221.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany34.0-7.20.041.731.76.036.145.226.220.141.948.635.29.628.237.932.411.837.545.022.522.827.550.732.719.639.240.812.911.847.440.530.48.538.039.624.417.530.044.933.210.40.046.3

Net Income Loss

us-gaap:NetIncomeLoss dei:LegalEntity

us-gaap:NetIncomeLoss

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value8614999778312096656212084636295775557792711946603398325446752954227732321271332826983834
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.57.54.75.98.37.33.94.57.75.93.74.06.05.53.23.75.22.06.43.24.22.55.32.33.53.44.52.03.41.74.72.32.20.83.52.01.71.64.32.11.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany13.718.10.013.114.616.614.711.511.315.712.511.210.712.511.49.69.911.24.517.68.58.96.015.06.27.27.313.15.67.03.914.16.24.72.011.05.93.94.313.26.14.2

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value11147-3.0297152-10.0-20.030010739-22.029416838-36.02341205.07.02429315112406242-5.0223127483323985411623714422-14.01919122
Percentage of NetIncomeLoss129.131.5-3.0385.7183.1-8.3-20.8461.5172.632.5-26.2466.7271.040.0-46.8425.5210.56.325.9203.4202.225.033.3244.9193.877.8-10.9297.3437.988.9150.0310.4265.6128.1133.3333.8436.478.6-53.8194.9239.564.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.53.0-0.218.210.9-0.7-1.518.17.82.5-1.617.110.72.4-2.613.67.80.30.513.06.51.00.813.14.42.7-0.413.48.93.02.514.66.12.81.111.88.71.3-0.98.45.11.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany13.76.70.029.719.2-1.5-3.228.313.45.1-3.126.017.64.8-5.221.012.80.60.920.810.72.01.520.57.05.2-0.720.314.15.94.321.99.65.22.422.317.13.2-2.117.111.12.8

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

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistribution


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value36343637413237363535333337313330
Percentage of NetIncomeLoss36.444.243.430.842.749.259.730.041.755.653.234.748.156.457.938.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.72.12.62.63.11.92.72.32.52.02.12.12.61.82.12.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistribution0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value41463637
Percentage of NetIncomeLoss47.730.943.430.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.82.92.62.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistributionSegment10.611.210.29.5

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisGas


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value332.09.05527-1.01.057210.07.042202.05.033
Percentage of NetIncomeLoss33.32.610.845.828.1-1.51.647.525.00.011.344.226.03.68.841.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.50.10.63.82.1-0.10.13.71.50.00.42.61.40.10.32.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisGas0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value8.0759.055
Percentage of NetIncomeLoss9.350.310.845.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.54.80.63.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisGasSegment4.821.66.420.3

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisTransmission


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value30413828283424272828222020221916
Percentage of NetIncomeLoss30.353.245.823.329.252.338.722.533.344.435.521.126.040.033.320.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.32.52.71.92.12.01.71.72.01.61.41.31.41.31.21.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisTransmission0.00.00.00.00.00.00.00.00.039.435.50.00.030.629.20.0

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisTransmissionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value37283828
Percentage of NetIncomeLoss43.018.845.823.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.51.82.71.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:OperatingSegments aee:AmerenIllinoisTransmissionSegment50.743.150.745.2

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value-8.018-13.017
Percentage of NetIncomeLoss-9.312.1-15.714.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.51.1-0.91.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MaterialReconcilingItems0.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistribution


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value36343637413237363535333337313330
Percentage of NetIncomeLoss36.444.243.430.842.749.259.730.041.755.653.234.748.156.457.938.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.72.12.62.63.11.92.72.32.52.02.12.12.61.82.12.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistribution0.08.710.29.50.08.210.39.30.08.98.58.20.07.78.57.8

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value41463637
Percentage of NetIncomeLoss47.730.943.430.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.82.92.62.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisElectricDistributionSegment10.611.210.29.5

us-gaap:OperatingSegments, aee:AmerenIllinoisGas


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value332.09.05527-1.01.057210.07.042202.05.033
Percentage of NetIncomeLoss33.32.610.845.828.1-1.51.647.525.00.011.344.226.03.68.841.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.50.10.63.82.1-0.10.13.71.50.00.42.61.40.10.32.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisGas0.01.66.420.30.0-0.90.717.80.00.04.913.50.01.83.712.5

us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value8.0759.055
Percentage of NetIncomeLoss9.350.310.845.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.54.80.63.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenIllinoisGasSegment4.821.66.420.3

us-gaap:OperatingSegments, aee:AmerenTransmission


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value48625947465342444348363734383434
Percentage of NetIncomeLoss48.580.571.139.247.981.567.736.751.276.258.138.944.269.159.643.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.63.84.23.33.53.23.02.83.02.82.32.32.42.22.22.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenTransmission0.044.043.438.20.041.438.538.60.042.535.035.60.031.932.40.0

us-gaap:OperatingSegments, aee:AmerenTransmissionSegment


Net
Period End2021-06-302021-03-312020-06-302020-03-31
Value55475947
Percentage of NetIncomeLoss64.031.571.139.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.73.04.23.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:AmerenTransmissionSegment46.241.647.642.7

us-gaap:OperatingSegments, aee:OtherSegment


Net
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.0-28.0-13.0170.0-20.0-8.015-9.0-20.0-5.01.0-115.0-17.01.00.0
Percentage of NetIncomeLoss1.0-36.4-15.714.20.0-30.8-12.912.5-10.7-31.7-8.11.1-149.4-30.91.80.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.1-1.7-0.91.20.0-1.2-0.61.0-0.6-1.2-0.30.1-8.2-1.00.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:OtherSegment0.00.00.00.00.00.00.00.00.00.00.00.00.0850.050.00.0

us-gaap:OperatingSegments, aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-03-31
Value11147-3.0297152-10.0-20.030010739-22.029416838-36.02345.0
Percentage of NetIncomeLoss129.131.5-3.0385.7183.1-8.3-20.8461.5172.632.5-26.2466.7271.040.0-46.8425.56.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.53.0-0.218.210.9-0.7-1.518.17.82.5-1.617.110.72.4-2.613.60.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments aee:UnionElectricCompany13.96.80.029.719.2-1.50.028.313.45.10.026.017.64.80.021.00.6

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2082351163692441489536618019369359240153-59.0290194104333711481073034515111049295150983830496-143.0-1155.0374210-403.0262871397454-164.0155106
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.115.08.722.717.510.37.222.113.112.44.920.815.49.7-4.216.812.66.92.420.010.47.52.318.810.87.13.617.710.66.12.918.66.8-9.7-76.518.712.7-24.31.612.77.83.93.2-7.29.05.5

us-gaap:ProfitLoss dei:LegalEntity

aee:AmerenIllinoisCompany


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value861501007784121976563121856363967855588030119466033983254467529542277323212713328269838343711057
Percentage of ProfitLoss41.363.886.220.934.481.8102.117.835.062.7123.217.526.262.7-132.219.029.976.990.932.131.156.1110.028.421.249.193.925.419.355.157.925.333.3-22.4-1.019.015.7-6.9100.034.127.345.968.5-67.136.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.67.54.76.08.47.43.94.67.86.03.74.06.15.63.23.85.32.26.43.24.22.55.32.33.53.44.52.03.41.74.72.32.20.83.52.01.71.64.32.11.82.24.93.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany13.718.20.013.114.816.714.811.511.515.912.611.210.912.611.69.610.111.45.017.68.58.96.015.06.27.27.313.15.67.03.914.16.24.72.011.05.93.94.313.26.14.20.014.78.8

aee:UnionElectricCompany


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value11248-3.0298153-9.0-20.030110840-22.029516939-36.02351216.010.02429315112406242-5.0223127483323985411623714422-14.019191222.0224115
Percentage of ProfitLoss53.820.4-2.680.862.7-6.1-21.182.260.020.7-31.982.270.425.561.081.062.45.830.365.262.814.036.769.641.138.2-10.275.684.749.086.878.688.5-28.7-1.463.468.6-5.5-53.866.665.529.73.7-136.674.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.63.1-0.218.310.9-0.6-1.518.17.82.6-1.617.110.82.5-2.613.67.90.40.713.06.51.00.813.14.42.7-0.413.48.93.02.514.66.12.81.111.88.71.3-0.98.45.11.20.19.96.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany13.86.80.029.819.3-1.3-3.228.413.55.3-3.126.117.74.9-5.221.113.00.81.320.810.72.01.520.57.05.2-0.720.314.15.94.321.99.65.22.422.317.13.2-2.117.111.12.80.021.115.1

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

aee:AmerenIllinoisCompany, us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value86150100778412197656312185636396
Percentage of ProfitLoss41.363.886.220.934.481.8102.117.835.062.7123.217.526.262.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.67.54.76.08.47.43.94.67.86.03.74.06.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

aee:UnionElectricCompany, us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value11248-3.0298153-9.0-20.030110840-22.029516939
Percentage of ProfitLoss53.820.4-2.680.862.7-6.1-21.182.260.020.7-31.982.270.425.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax7.63.1-0.218.310.9-0.6-1.518.17.82.6-1.617.110.82.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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
Value5.06.05.05.05.06.05.05.04.06.05.05.04.06.05.04.04.04.00.05.06.06.04.06.06.08.05.05.06.09.08.05.05.09.06.0114.08.0
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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-871.0-889.0-1348.0-666.0-631.0-684.0-637.0-644.0-587.0-567.0-617.0-590.0-532.0-597.0-620.0-526.0-520.0-539.0-590.0-516.0-525.0-510.0-614.0-487.0-436.0-439.0-505.0-442.0-457.0-313.0-690.0-396.0-334.0-303.0-299.0-373.0-312.0-326.0-291.0-259.0-248.0-250.0-336.0-216.0-243.0-317.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-59.2-56.8-101.5-40.9-45.1-47.5-48.4-38.8-42.6-36.4-43.5-34.2-34.0-37.7-44.2-30.5-33.8-35.6-43.5-27.8-36.8-35.6-46.9-26.6-31.1-28.2-36.9-26.5-32.2-19.6-52.2-24.2-23.8-20.5-19.8-18.6-18.8-19.7-18.4-11.4-13.9-13.1-19.7-9.5-14.1-16.3

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-331.0-337.0-414.0-371.0-336.0-323.0-302.0-345.0-291.0-267.0-311.0-338.0-299.0-300.0-316.0-274.0-253.0-227.0-239.0-241.0-169.0-269.0-298.0-240.0-168.0-207.0-201.0-195.0-218.0-214.0-239.0-177.0-141.0-138.0-133.0-57.0-161.0-86.0-84.0-87.0-106.0-19.0-64.0-72.0
Percentage of NetCashProvidedByUsedInInvestingActivities38.037.930.755.753.247.247.453.649.647.150.457.356.250.351.052.148.742.140.546.732.252.748.549.338.547.239.844.147.768.434.644.742.245.544.515.351.626.428.933.642.77.619.033.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-22.5-21.5-31.2-22.8-24.0-22.4-22.9-20.8-21.1-17.2-21.9-19.6-19.1-18.9-22.5-15.9-16.5-15.0-17.6-13.0-11.8-18.8-22.8-13.1-12.0-13.3-14.7-11.7-15.4-13.4-18.1-10.8-10.0-9.4-8.8-2.8-9.7-5.2-5.3-3.8-6.0-1.0-3.8-3.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany-52.6-40.90.0-63.0-59.3-44.7-46.2-61.2-53.2-35.0-46.1-59.9-51.7-39.5-46.9-47.7-43.9-32.3-40.2-35.7-31.2-39.7-53.9-36.6-32.7-27.8-31.8-34.1-42.0-27.6-42.4-32.4-27.3-20.2-22.6-8.8-28.5-11.9-13.7-11.7-17.0-2.40.0-9.7

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-655.0-398.0-1027.0-273.0-276.0-328.0-310.0-264.0-257.0-264.0-241.0-192.0-278.0-265.0-230.0-202.0-185.0-68.0-210.0-370.0-184.0-170.015-411.0-159.0-169.0-244.0-180.0-209.0-204.0-181.0-221.0-156.0-129.0-133.0-177.0-175.0-218.0-168.0-139.0-164.0-156.0-219.0-130.0
Percentage of NetCashProvidedByUsedInInvestingActivities75.244.876.241.043.748.048.741.043.846.639.132.552.344.437.138.435.612.635.671.735.033.3-2.484.436.538.548.340.745.765.226.255.846.742.644.547.556.166.957.753.766.162.465.260.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-44.5-25.4-77.3-16.8-19.7-22.8-23.6-15.9-18.6-17.0-17.0-11.1-17.8-16.7-16.4-11.7-12.0-4.5-15.5-19.9-12.9-11.91.1-22.4-11.3-10.9-17.8-10.8-14.7-12.8-13.7-13.5-11.1-8.7-8.8-8.8-10.5-13.1-10.6-6.1-9.2-8.2-12.8-5.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:UnionElectricCompany-81.0-56.50.0-27.3-34.8-48.2-49.4-24.9-32.2-34.8-33.8-17.0-29.1-33.5-32.9-18.1-19.8-8.6-28.0-31.8-21.2-22.92.0-35.1-18.0-21.1-33.0-16.4-23.2-25.0-23.7-20.2-17.5-16.2-19.8-16.6-20.7-31.5-24.9-12.5-20.0-20.20.0-12.3

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
Value652694785656592636650636581544597577533579609525494504580496504496585486429417475427441442436368300275335340283282272251280227274210258289
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

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment dei:LegalEntity

aee:AmerenIllinoisCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value30933741637033732430834428926731134530230031627625722724124123121129824120517420219722121523917915013313312598869087105696668
Percentage of PaymentsToAcquirePropertyPlantAndEquipment47.448.653.056.456.950.947.454.149.749.152.159.856.751.851.952.652.045.041.648.645.842.550.949.647.841.742.546.150.148.654.848.650.048.439.736.834.630.533.134.737.530.424.132.4

aee:UnionElectricCompany


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value343341324262238278325256255240250210205249240178159196238147175178178155144145199173187188168207136137150146142157148130143129179124
Percentage of PaymentsToAcquirePropertyPlantAndEquipment52.649.141.339.940.243.750.040.343.944.141.936.438.543.039.433.932.238.941.029.634.735.930.431.933.634.841.940.542.442.538.556.245.349.844.842.950.255.754.451.851.156.865.359.0

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

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistribution


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value129139123128139127124114135132122122112122120111123119117
Percentage of PaymentsToAcquirePropertyPlantAndEquipment19.723.519.319.721.921.922.819.123.424.821.120.021.324.723.819.124.823.623.6

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisGas


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value8179617711377517411166606571585151504535
Percentage of PaymentsToAcquirePropertyPlantAndEquipment12.313.39.611.817.813.39.412.419.212.410.410.713.511.710.18.810.18.97.1

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisTransmission


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value1601191401039285921239910411812993775679686759
Percentage of PaymentsToAcquirePropertyPlantAndEquipment24.420.122.015.814.514.616.920.617.219.520.421.217.715.611.113.613.713.311.9

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-3.02.01.0-31.06.0-5.0-2.0-3.0-4.02.0-4.03.0-7.0-2.0-1.0-6.00.00.00.0
Percentage of PaymentsToAcquirePropertyPlantAndEquipment-0.50.30.2-4.80.9-0.9-0.4-0.5-0.70.4-0.70.5-1.3-0.4-0.2-1.00.00.00.0

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

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistribution


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value129139123128139127124114135132122122112122120111123119117
Percentage of PaymentsToAcquirePropertyPlantAndEquipment19.723.519.319.721.921.922.819.123.424.821.120.021.324.723.819.124.823.623.6

us-gaap:OperatingSegments, aee:AmerenIllinoisGas


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value8179617711377517411166606571585151504535
Percentage of PaymentsToAcquirePropertyPlantAndEquipment12.313.39.611.817.813.39.412.419.212.410.410.713.511.710.18.810.18.97.1

us-gaap:OperatingSegments, aee:AmerenTransmission


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value185135170151129127121163124130145181173156134186175164164
Percentage of PaymentsToAcquirePropertyPlantAndEquipment28.222.826.723.220.321.922.227.321.524.425.029.733.031.626.632.135.332.533.1

us-gaap:OperatingSegments, aee:OtherSegment


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value2.0-1.03.00.0-7.00.010.0-1.01.0-2.07.0-2.0-2.01.04.00.01.01.02.0
Percentage of PaymentsToAcquirePropertyPlantAndEquipment0.3-0.20.50.0-1.10.01.8-0.20.2-0.41.2-0.3-0.40.20.80.00.20.20.4

us-gaap:OperatingSegments, aee:UnionElectricCompany


Payments
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value262238278325256255240250210205249240178159196238147175178
Percentage of PaymentsToAcquirePropertyPlantAndEquipment39.940.243.750.040.343.944.141.936.438.543.039.433.932.238.941.029.634.735.9

Payments To Acquire Productive Assets

us-gaap:PaymentsToAcquireProductiveAssets

us-gaap:PaymentsToAcquireProductiveAssets


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value876887592636
Percentage of PaymentsToAcquireProductiveAssets100.0100.0100.0100.0

us-gaap:PaymentsToAcquireProductiveAssets dei:LegalEntity

aee:AmerenIllinoisCompany


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value309337337324
Percentage of PaymentsToAcquireProductiveAssets35.338.056.950.9

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

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value129157139123
Percentage of PaymentsToAcquireProductiveAssets14.717.723.519.3

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value61487961
Percentage of PaymentsToAcquireProductiveAssets7.05.413.39.6

aee:AmerenIllinoisCompany, us-gaap:OperatingSegments, aee:AmerenIllinoisTransmissionSegment


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value119132119140
Percentage of PaymentsToAcquireProductiveAssets13.614.920.122.0

us-gaap:PaymentsToAcquireProductiveAssets us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value-12.06.02.01.0
Percentage of PaymentsToAcquireProductiveAssets-1.40.70.30.2

us-gaap:MaterialReconcilingItems


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value0.01.0-1.03.0
Percentage of PaymentsToAcquireProductiveAssets0.00.1-0.20.5

us-gaap:PaymentsToAcquireProductiveAssets us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, aee:AmerenIllinoisElectricDistributionSegment


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value129157139123
Percentage of PaymentsToAcquireProductiveAssets14.717.723.519.3

us-gaap:OperatingSegments, aee:AmerenIllinoisGasSegment


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value61487961
Percentage of PaymentsToAcquireProductiveAssets7.05.413.39.6

us-gaap:OperatingSegments, aee:AmerenTransmissionSegment


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value131141135170
Percentage of PaymentsToAcquireProductiveAssets15.015.922.826.7

us-gaap:OperatingSegments, aee:UnionElectricCompany


Payments
Period End2021-06-302021-03-312020-06-302020-03-31
Value567534238278
Percentage of PaymentsToAcquireProductiveAssets64.760.240.243.7

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
Value495795108336187421156-112.099191148-280.0-23.0360160-255.0-10.020717-275.0111-118.0345-204.0-37.0142149-140.06270147-131.0-66.0-99.0-119.0-2.0-192.0-113.0-288.0-260.0-296.0-276.0-73.0-407.0-2.0-325.0
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax33.650.881.62.213.429.211.9-6.87.212.310.4-16.2-1.522.711.4-14.8-0.713.71.3-14.87.8-8.226.4-11.1-2.69.110.9-8.44.44.411.1-8.0-4.7-6.7-7.9-0.1-11.6-6.8-18.3-11.5-16.6-14.5-4.3-18.0-0.1-16.8

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

aee:AmerenIllinoisCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value15132625020123010654109725317712314718112921901560-1.016-31.01478536-48.0152991102295-1.0-9.0-40.0-38.09.0-37.0-37.0-77.0-83.0-239.0-110.0-33.0-153.0
Percentage of NetCashProvidedByUsedInFinancingActivities30.541.023.1558.3123.025.234.6-97.372.727.7119.6-43.9-639.150.380.6-8.2-900.07.2352.90.414.426.342.6-41.7-97.3-33.8102.0-70.7177.431.464.60.813.640.431.9-450.019.332.726.731.980.739.945.237.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.320.818.812.316.57.44.16.65.23.412.57.19.411.49.21.25.91.04.4-0.11.1-2.211.24.62.6-3.111.15.97.81.47.2-0.1-0.6-2.7-2.50.4-2.2-2.2-4.9-3.7-13.4-5.8-1.9-6.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax aee:AmerenIllinoisCompany24.039.60.034.140.614.78.319.313.27.026.321.825.423.819.13.715.62.110.1-0.13.0-4.626.613.07.0-6.424.017.321.22.816.8-0.2-1.7-5.8-6.51.4-6.6-5.1-12.6-11.1-38.4-13.60.0-20.5

aee:UnionElectricCompany


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value385