ES


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue

us-gaap:CommonStockSharesIssued
dei:LegalEntity

us-gaap:CommonStockSharesOutstanding
us-gaap:StatementEquityComponents

us-gaap:CommonStockSharesAuthorized

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

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

us-gaap:OperatingExpenses
dei:LegalEntity

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

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
dei:LegalEntity

us-gaap:NonoperatingIncomeExpense

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest

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

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

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

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

us-gaap:LiabilitiesAndStockholdersEquity
dei:LegalEntity

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

us-gaap:AssetsCurrent
dei:LegalEntity

us-gaap:Cash
dei:LegalEntity

us-gaap:AccountsReceivableNetCurrent
dei:LegalEntity

us-gaap:InventoryRawMaterialsAndSupplies
dei:LegalEntity

us-gaap:OtherAssetsCurrent
dei:LegalEntity

us-gaap:Goodwill

us-gaap:OtherAssetsNoncurrent
dei:LegalEntity

us-gaap:LiabilitiesCurrent
dei:LegalEntity

us-gaap:LongTermDebtCurrent
dei:LegalEntity

us-gaap:AccountsPayableCurrent
dei:LegalEntity

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

us-gaap:LongTermDebtNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity

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

us-gaap:CommonStockValue

us-gaap:RetainedEarningsAccumulatedDeficit
dei:LegalEntity

us-gaap:TreasuryStockValue

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

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

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

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet
dei:LegalEntity

us-gaap:IncreaseDecreaseInInventories
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

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

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:ShortTermDebtType

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

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity

us-gaap:ProceedsFromRepaymentsOfShortTermDebt
dei:LegalEntity

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

es:AmountofNaturalGasToBePurchasedUnderFuturesContracts

es:DerivativeInstrumentsGainLossRecognizedInRegulatoryAssetLiability

es:EnergyEfficiencyPrograms
dei:LegalEntity

es:EnvironmentalSiteQuantity
dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
es:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityGainLossIncludedInRegulatoryAssetLiability

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

es:LossContingencyPercentageOfBaseROEReasonablyJustified

es:LossContingencyPercentageOfIncentiveCapOnTotalROE
us-gaap:LossContingenciesByNatureOfContingency
es:LossContingencyPercentageofROEforAnyIncentiveProject
dei:LegalEntity
es:PensionSERPandPBOPExpenseNetofContributions
us-gaap:Range, us-gaap:FairValueByFairValueHierarchyLevel
es:PercentageofExitPricePremiums
us-gaap:RetirementPlanType, dei:LegalEntity
es:RelatedIntercompanyAllocationsofDefinedBenefitExpense

es:RepaymentsOfRateReductionBonds
dei:LegalEntity

es:UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed
dei:LegalEntity

us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts
us-gaap:StatementEquityComponents

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

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

us-gaap:AmortizationOfDeferredCharges
dei:LegalEntity
us-gaap:AmortizationOfRegulatoryAsset
us-gaap:ConsolidatedEntities, us-gaap:DebtInstrument, dei:LegalEntity
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType
us-gaap:BusinessCombinationConsiderationTransferred1

us-gaap:CapitalExpendituresIncurredButNotYetPaid
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect
dei:LegalEntity

us-gaap:CommonStockDividendsPerShareCashPaid

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

us-gaap:Depreciation
dei:LegalEntity

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

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

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:ExciseAndSalesTaxes
dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements

us-gaap:ForwardContractIndexedToIssuersEquityShares

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables
dei:LegalEntity

us-gaap:IncreaseDecreaseInAccountsPayable
dei:LegalEntity
dei:LegalEntity
us-gaap:IncreaseDecreaseInDueToRelatedParties

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable
dei:LegalEntity

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities
dei:LegalEntity

us-gaap:IncrementalCommonSharesAttributableToEquityForwardAgreements
dei:LegalEntity
us-gaap:NumberOfReportableSegments

us-gaap:OperatingLeaseLeaseIncome
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax
dei:LegalEntity

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

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
dei:LegalEntity

us-gaap:OtherNoncashIncomeExpense
dei:LegalEntity

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsOfDividendsCommonStock
dei:LegalEntity

us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock
dei:LegalEntity

us-gaap:PaymentsToAcquireEquityMethodInvestments

us-gaap:PaymentsToAcquireMarketableSecurities

us-gaap:PensionAndOtherPostretirementBenefitContributions
dei:LegalEntity

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

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

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromSaleAndMaturityOfMarketableSecurities

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

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
us-gaap:StatementEquityComponents

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

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

us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesTreasuryStockReissued

us-gaap:StockIssuedDuringPeriodValueNewIssues
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueTreasuryStockReissued
us-gaap:StatementEquityComponents

us-gaap:TaxesExcludingIncomeAndExciseTaxes
dei:LegalEntity

us-gaap:UtilitiesOperatingExpenseMaintenanceAndOperations
dei:LegalEntity

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

us-gaap:WeightedAverageNumberDilutedSharesOutstandingAdjustment

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity

es:AmountofCapacityProvidedUnderCapacityContract
us-gaap:SubsequentEventType, dei:LegalEntity
es:DebtInstrumentAuthorizedAmountAvailableForIssuance

es:ElectricAndNaturalGasUtilityAccumulatedDepreciation

es:OtherAccumulatedDepreciation
dei:LegalEntity
es:PensionAndOtherPostretirementDefinedBenefitPlansAssetsNoncurrent

es:PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress
dei:LegalEntity

es:PublicUtilitiesPropertyPlantAndEquipmentDistributionNaturalGas

es:PublicUtilitiesPropertyPlantAndEquipmentDistributionWater

es:PublicUtilitiesPropertyPlantAndEquipmentElectricAndNaturalGasUtilityTotal

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

es:RateReductionBondsCurrent
dei:LegalEntity

es:RenewablePortfolioStandardsComplianceObligation
dei:LegalEntity
dei:LegalEntity
us-gaap:AccountsPayableOtherCurrent
dei:LegalEntity
us-gaap:AccountsPayableRelatedPartiesCurrent
dei:LegalEntity
us-gaap:AccountsReceivableRelatedPartiesCurrent

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

us-gaap:AdditionalPaidInCapital
dei:LegalEntity

us-gaap:AllowanceForDoubtfulAccountsReceivable
dei:LegalEntity
es:CumulativeEffectPeriodOfAdoption, dei:LegalEntity
es:CumulativeEffectPeriodOfAdoption, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
es:CumulativeEffectPeriodOfAdoption, us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity

us-gaap:AmountOfRegulatoryCostsNotYetApproved
dei:LegalEntity

us-gaap:AssetRetirementObligationsNoncurrent

us-gaap:AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment
dei:LegalEntity

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis

us-gaap:AvailableForSaleSecuritiesDebtSecurities

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

us-gaap:DeferredIncomeTaxLiabilitiesNet
dei:LegalEntity
dei:LegalEntity
us-gaap:DepositsAssetsCurrent
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:DerivativeAssetFairValueGrossLiability
us-gaap:Range, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:MeasurementInputType, dei:LegalEntity
us-gaap:DerivativeAssetLiabilityNetMeasurementInput
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:DerivativeFairValueOfDerivativeAsset
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
dei:LegalEntity
us-gaap:DerivativeLiabilitiesCurrent

us-gaap:DerivativeLiabilitiesNoncurrent
dei:LegalEntity
us-gaap:BalanceSheetLocation, us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:DerivativeLiabilityFairValueGrossAsset

us-gaap:EquityMethodInvestments

us-gaap:EquitySecuritiesFvNi
dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
us-gaap:GuaranteeObligationsByNature
us-gaap:GuaranteeObligationsMaximumExposure
dei:LegalEntity
us-gaap:InterestPayableCurrent

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

us-gaap:LiabilitiesOtherThanLongtermDebtNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:ShortTermDebtType
us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:ShortTermDebtType
us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity
us-gaap:ShortTermDebtType, dei:LegalEntity
us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingencyEstimateOfPossibleLoss
dei:LegalEntity
us-gaap:MarketableSecurities

us-gaap:MarketableSecuritiesNoncurrent

us-gaap:NotesPayable
dei:LegalEntity
dei:LegalEntity
us-gaap:NotesPayableRelatedPartiesClassifiedCurrent
dei:LegalEntity
us-gaap:NotesPayableRelatedPartiesCurrentAndNoncurrent

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciation
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentDistribution
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentGenerationOrProcessing
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentNet
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentPlantInService
dei:LegalEntity

us-gaap:PublicUtilitiesPropertyPlantAndEquipmentTransmission
dei:LegalEntity

us-gaap:ReceivablesFromCustomers
dei:LegalEntity

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

us-gaap:RegulatoryAssets

us-gaap:RegulatoryAssetsCurrent
dei:LegalEntity

us-gaap:RegulatoryAssetsNoncurrent
dei:LegalEntity

us-gaap:RegulatoryLiabilities

us-gaap:RegulatoryLiabilityCurrent
dei:LegalEntity

us-gaap:RegulatoryLiabilityNoncurrent
dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:RegulatoryAsset, dei:LegalEntity
us-gaap:BalanceSheetLocation
us-gaap:RestrictedCashAndCashEquivalents
us-gaap:BalanceSheetLocation, dei:LegalEntity
us-gaap:ConsolidatedEntities, us-gaap:BalanceSheetLocation, dei:LegalEntity
us-gaap:ShortTermDebtType
us-gaap:ShortTermBorrowings
us-gaap:ShortTermDebtType, dei:LegalEntity
us-gaap:ShortTermDebtType
us-gaap:ShortTermDebtWeightedAverageInterestRate
us-gaap:ShortTermDebtType, dei:LegalEntity
us-gaap:StatementEquityComponents
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:TreasuryStockShares

Tables

  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:CommonStockValue █▆▄▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁1759172916991699166916691669166916691669166916691669166916691669166916691669166916681666166616661666166516651664166416621662NA981980980979NA978NANANA
us-gaap:CommonStockSharesIssued █▆▄▄▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁351345339339333333333333333333333333333333333333333333333333333333333333333333333332332332332NA196196196195NA195NANANA
 us-gaap:CommonStockSharesIssued dei:LegalEntity es:NstarElectricCompany██████████▁▁▁▁▁▁▁▁▁▁▁▁200.0200.0200.0200.0200.0200.0200.0200.0200.0200.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0NANANANANANANANANANANANANANANANANANANA
us-gaap:CommonStockSharesOutstanding █▆▄▄▂▁▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▁▁▁▁▁336329323323317316316316316316316316316316317317317317317317317316316316315315NANANANANANANANANANANANANANANA
 us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock█▆▃▃▁▁▁▁▁▁336329323323317316316316316316NANANA316NANANA317NANANA316NANANA315NANANA314NANANA177NANANA176NANANA
us-gaap:CommonStockSharesAuthorized ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄380380380380380380380380380380380380380380380380380380380380380380380380380380380380380380380NA380380225225NA225NANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding 332NA326320318NA317317317NA317317318NA318318318NA318318318NA317317316NA316315316NA315301178NA177177177NA177176NA
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic 331NA324319317NA317317317NA317317317NA317317317NA317317317NA316315315NA315315315NA314301178NA177177177NA176176NA
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  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
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 us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity es:NstarElectricCompany█▁▁█▁▁▁40000400000NANA3500NANA00NANA250000000300NANANANANANANANANANANANANANANANA
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us-gaap:RepaymentsOfLongTermDebt ▃▆▁▁▃▃▁█▂▅▃▁▂▁▁▃▁▁▁▃▁▁▃▄▂▂▆▅▁▇▁220550002501890710150425170015000200005016600200301758947936005710NANA2450NANA00NANA
 us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity es:NstarElectricCompany95NANANA0NANANANA4000NANA00NANA00NANA00NANANANANANANANANANANANANANANANANANA
 us-gaap:RepaymentsOfLongTermDebt us-gaap:DebtInstrument,us-gaap:LongtermDebtType,dei:LegalEntity es:A5.10SeriesESeniorNotes,us-gaap:SeniorNotes,es:NstarElectricCompany95NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:RepaymentsOfLongTermDebt ▃▆▁▁▃▃▁█▂▅▃▁▂▁▁▃▁▁▁▃▁▁▃▄▂▂▆▅▁▇▁220550002501890710150425170015000200005016600200301758947936005710NANA2450NANA00NANA
 us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity es:NstarElectricCompany95NANANA0NANANANA4000NANA00NANA00NANA00NANANANANANANANANANANANANANANANANANA
 us-gaap:RepaymentsOfLongTermDebt us-gaap:DebtInstrument,us-gaap:LongtermDebtType,dei:LegalEntity es:A5.10SeriesESeniorNotes,us-gaap:SeniorNotes,es:NstarElectricCompany95NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1759172916991699166916691669166916691669166916691669166916691669166916691669166916681666166616661666166516651664166416621662981980980979978
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.24.24.34.44.34.44.44.54.54.65.05.15.25.25.45.45.45.55.65.65.65.66.06.05.96.05.95.95.95.96.06.16.36.76.86.8

Common Stock Par Or Stated Value Per Share

Common Stock Shares Issued

us-gaap:CommonStockSharesIssued



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value351345339339333333333333333333333333333333333333333333333333333333333333333333333332332332332196196196195195
Percentage of CommonStockSharesIssued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value200.0200.0200.0200.0200.0200.0200.0200.0200.0200.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of CommonStockSharesIssued0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-04-09
Value336329323323317316316316316316316316316316317317317317317317317316316316315315314
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value336329323323317316316316316316316317316315314177176175155
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0

Common Stock Shares Authorized

us-gaap:CommonStockSharesAuthorized



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value380380380380380380380380380380380380380380380380380380380380380380380380380380380380380380380380380225225225
Percentage of CommonStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value332326320318317317317317317318318318318318318318317317316316315316315301178177177177177176
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value331324319317317317317317317317317317317317317317316315315315315315314301178177177177176176
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

Earnings Per Share Diluted

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value22942050216818682397203423211860227718951988176221051776203917672055169119331817251318811892167722901777189216351995168418611628109910681114104712351204124311111339
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value23732050217518842415203422711853228818951988176221051776203917672055169119331817251318811892167722901777189216351995168418611628109910681114104712351204124311111339
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax103.5100.0100.3100.9100.8100.097.999.6100.5100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value733686878681797712939690770690725584603571780591614546750617766581727561666
Percentage of Revenues30.933.540.436.233.035.041.437.333.736.436.533.128.732.238.333.529.932.338.834.030.530.938.533.529.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax32.033.540.536.533.335.040.537.133.836.436.533.128.732.238.333.529.932.338.834.030.530.938.533.529.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value276268280240276254290235267
Percentage of Revenues11.613.112.912.811.412.512.812.711.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.013.112.912.911.512.512.512.611.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value899788853740849751865694784713774666732630760679735626704666804675695587734
Percentage of Revenues37.938.539.239.335.236.938.137.534.337.739.037.834.835.537.338.535.837.136.436.732.035.936.835.032.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax39.238.539.439.735.436.937.337.334.537.739.037.834.835.537.338.535.837.136.436.732.035.936.835.032.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value294261258250258243224237230
Percentage of Revenues12.412.711.913.310.712.09.912.810.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax12.812.711.913.410.812.09.712.710.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-591-544-529-539-531-509-483-500-472-272-220-240-252-241-201-229-220-212-198
Percentage of Revenues-24.9-26.6-24.3-28.6-22.0-25.0-21.3-27.0-20.6-14.4-11.1-13.7-12.0-13.6-9.9-13.0-10.7-12.5-10.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-25.8-26.6-24.4-28.9-22.2-25.0-20.8-26.9-20.7-14.4-11.1-13.7-12.0-13.6-9.9-13.0-10.7-12.5-10.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination104.90.096.5112.2102.10.093.5100.697.80.00.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, dei:LegalEntity

srt:ConsolidationEliminations, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-106-105-96-99-98-97-100-96
Percentage of Revenues-4.5-5.2-4.4-5.3-4.1-4.8-4.4-5.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-4.6-5.2-4.4-5.3-4.1-4.8-4.3-5.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:ConsolidationEliminations es:NstarElectricCompany0.00.00.00.00.00.00.00.0

srt:ConsolidationEliminations, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-37-37
Percentage of Revenues-1.6-1.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.6-1.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:ConsolidationEliminations es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

srt:ConsolidationEliminations, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-122-119-131-115-116-116-121-107
Percentage of Revenues-5.1-5.8-6.0-6.1-4.8-5.7-5.3-5.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-5.3-5.8-6.0-6.2-4.9-5.7-5.2-5.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax srt:ConsolidationEliminations es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value180516491931156118331635202715391754
Percentage of Revenues76.180.488.882.975.980.489.383.176.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax78.780.489.183.676.580.487.382.877.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution102.40.0100.7100.7100.30.097.799.3100.7

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value369351347349340333330317305
Percentage of Revenues15.617.116.018.614.116.414.617.113.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax16.117.116.018.714.216.414.217.113.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission108.80.094.4122.7103.80.089.9101.196.3

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value465164534550635344
Percentage of Revenues2.02.53.02.81.92.52.82.91.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.02.53.02.91.92.52.72.92.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value44828210320746828110920642424810918640323599180342195106
Percentage of Revenues18.913.84.811.019.413.84.811.118.613.15.510.619.213.34.910.216.711.65.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax19.613.84.811.119.613.84.711.118.713.15.510.619.213.34.910.216.711.65.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution108.00.093.899.1102.40.099.2100.499.80.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:WaterDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value465164534550635344
Percentage of Revenues2.02.53.02.81.92.52.82.91.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.02.53.02.91.92.52.72.92.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments us-gaap:WaterDistribution102.90.0104.7101.7102.70.0101.9104.1101.8

Operating Expenses

us-gaap:OperatingExpenses



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value18341614166617331921163418051462184514441485130715961338152913431567130514631405201514501451138318221417149312851576135214481469885883911869100710081043933
Percentage of OperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax80.078.876.992.880.180.377.878.681.076.274.774.275.875.375.076.076.277.275.777.380.277.176.782.579.679.778.978.679.080.377.890.280.582.781.783.081.683.883.984.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value587550659547659586733557651833526436476467571460504428536465607449521439547
Percentage of OperatingExpenses32.034.139.631.634.335.940.738.135.357.735.433.429.834.937.434.332.232.836.733.230.131.035.931.830.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax25.626.930.429.327.528.831.629.928.644.026.524.722.626.328.026.124.525.427.825.624.223.927.526.223.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value214226
Percentage of OperatingExpenses11.711.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax9.49.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value713635663574677608692531627558597490556467583517563472543512663516549495576
Percentage of OperatingExpenses38.939.439.833.135.337.238.336.434.038.640.237.534.934.938.238.536.036.237.136.532.935.637.935.831.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax31.131.030.630.728.329.929.828.627.629.430.027.826.426.328.629.327.428.028.128.226.427.429.029.525.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value539435509150494400466391442450502455509438509423488385469412497430440293467360399350418331412159214184203178227195199178226
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax23.521.223.58.120.619.720.121.019.423.825.325.924.224.725.024.023.822.824.322.719.822.923.317.520.420.321.121.421.019.722.29.819.517.318.317.018.416.216.116.016.9

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value146135219134137126205133118128199147127104208130109117214151159132206121118
Percentage of OperatingIncomeLoss27.131.143.188.927.931.544.134.226.928.639.632.425.023.940.930.822.530.545.636.732.130.746.941.325.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.46.610.17.25.76.28.97.25.26.810.08.46.15.910.27.45.37.011.18.36.37.010.97.25.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value615664464937564655
Percentage of OperatingIncomeLoss11.412.912.730.710.09.312.112.012.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.72.73.02.52.11.82.42.52.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value18515219016617114217216315715517717617616317616217115416115314115914692158
Percentage of OperatingIncomeLoss34.535.137.4110.534.735.737.041.735.534.535.338.634.637.334.538.335.140.034.337.428.537.033.231.333.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.17.48.88.97.27.07.48.86.98.28.910.08.49.28.69.28.39.18.38.55.68.57.75.56.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1672-35171916111314
Percentage of OperatingIncomeLoss3.016.6-6.911.73.84.12.53.43.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.73.5-1.60.90.80.80.50.70.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment5.50.0-13.67.17.40.05.25.76.1

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value0-10810900001000000-10000
Percentage of OperatingIncomeLoss0.1-25.021.50.10.10.10.10.40.10.10.00.20.10.1-0.20.20.10.10.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-5.35.10.00.00.00.00.10.00.00.00.10.00.0-0.10.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination-0.10.0-20.0-0.0-0.10.0-0.1-0.3-0.10.00.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value198157295168179139259171166
Percentage of OperatingIncomeLoss36.836.157.9111.736.234.955.643.837.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.67.713.69.07.56.911.29.27.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution11.30.015.410.99.80.012.511.19.6

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value195241123-60180166175171165
Percentage of OperatingIncomeLoss36.255.424.3-40.236.441.637.743.837.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.511.85.7-3.27.58.27.69.27.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission57.50.033.6-21.354.90.047.854.652.2

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value10132716812261610
Percentage of OperatingIncomeLoss1.93.15.411.11.83.25.64.32.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.71.30.90.40.61.10.90.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value11759-12810764-7168552-1189251-3229333-4
Percentage of OperatingIncomeLoss21.913.7-2.45.621.716.1-1.64.219.411.6-0.34.018.111.8-0.75.319.18.7-0.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.12.9-0.60.44.53.2-0.30.93.82.7-0.11.04.42.9-0.21.34.52.0-0.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution28.40.0-10.94.023.40.0-6.68.120.20.00.00.00.00.00.00.00.00.00.0

Interest Expense

us-gaap:InterestExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value13413313513213112612512612110210810710310299100989292929489899289888786768490896665636258366567
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.96.56.27.15.56.25.46.85.35.45.56.14.95.84.95.74.85.54.85.13.84.84.75.53.95.04.65.33.85.04.95.56.06.25.75.94.73.15.36.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value31282928272426272635242322212120201818172018172021
Percentage of InterestExpense23.021.521.721.321.219.421.521.621.835.022.521.821.321.321.120.121.319.520.519.321.620.919.322.423.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.41.41.41.51.21.21.21.51.21.91.21.31.01.21.01.11.01.11.01.00.81.00.91.20.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value1414
Percentage of InterestExpense10.710.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.60.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value37393936353837383636363534353635363636363636383734
Percentage of InterestExpense28.129.329.227.927.230.630.030.630.435.633.432.933.834.736.135.837.239.239.739.238.641.143.240.538.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.91.82.01.51.91.62.11.61.91.82.01.72.01.82.01.82.11.92.01.52.02.02.21.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

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



Period End2020-03-312019-03-31
Value55
Percentage of InterestExpense3.74.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.20.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:VariableInterestEntityPrimaryBeneficiary es:RateReductionBonds es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value424041444434303231
Percentage of InterestExpense31.730.030.833.533.627.424.425.626.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.92.01.92.41.81.71.31.71.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment14.50.016.217.717.10.013.613.613.8

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-11-11-13-13-12-9-7-8-7-4-4-3-3-2-1-1-2-1-1
Percentage of InterestExpense-8.8-8.4-10.3-10.2-9.6-7.2-6.2-6.3-6.1-4.7-4.0-3.3-3.1-2.1-1.3-1.5-2.0-1.3-1.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-0.5-0.5-0.6-0.7-0.5-0.4-0.3-0.4-0.3-0.3-0.2-0.2-0.2-0.1-0.1-0.1-0.1-0.1-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination2.10.02.52.82.40.01.51.61.50.00.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value535353504950525247
Percentage of InterestExpense39.439.839.338.337.440.341.941.239.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.32.62.52.72.12.52.32.82.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution3.00.02.83.32.70.02.53.42.7

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value303133303030303029
Percentage of InterestExpense22.723.424.823.023.224.424.223.724.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.31.51.51.61.31.51.31.61.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission9.00.09.110.79.30.08.29.69.4

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value888888888
Percentage of InterestExpense6.56.36.66.56.57.06.86.86.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.40.40.40.50.40.40.40.50.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value111211111110111111101010101010101099
Percentage of InterestExpense8.59.08.79.08.98.29.09.09.210.69.910.210.310.310.210.310.310.59.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.60.50.60.50.50.50.60.50.60.50.60.50.60.50.60.50.60.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution2.70.010.65.72.60.010.35.52.60.00.00.00.00.00.00.00.00.00.0

Interest Expense Long Term Debt

Other Nonoperating Income Expense

Income Loss From Continuing Operations Before Income Taxes Domestic

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value4283304006439330135731535537041536941935742333039230338133240834536320737928032026835025232672156127141123179180143112
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.716.118.53.416.414.815.416.915.619.520.921.019.920.120.818.719.117.919.818.316.218.419.212.316.615.816.916.417.615.017.64.414.312.012.711.814.515.011.610.1

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value127118200116121114192120105203177126108861921138810119513613911419210097
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic29.835.950.1181.830.737.853.838.329.655.042.934.225.924.145.534.222.633.351.240.934.233.153.048.625.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.65.89.36.25.05.68.36.54.610.88.97.25.24.89.46.44.36.010.17.55.66.110.26.04.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value5042
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic11.710.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.21.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value14911915513213910614213112612614814414313014313213512012612110712411357124
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic35.036.138.8206.835.535.239.841.735.734.135.839.134.336.533.940.034.639.833.236.626.336.031.427.932.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax6.55.87.27.15.85.26.17.15.66.77.58.26.87.37.07.56.67.16.66.74.36.66.03.45.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value242826453127165033212121132213821051255115188474418
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.11.41.22.51.31.40.72.71.51.11.11.20.61.30.70.50.10.60.30.70.20.30.60.30.10.50.50.30.40.30.20.10.8

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value917980308368667083130152137157126156125146119144123153122126771411011099512075117265513494463494139
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.03.93.71.63.53.42.93.83.76.97.77.87.57.17.77.17.17.17.56.86.16.56.74.66.25.75.85.86.04.56.31.65.11.24.54.25.14.13.43.5

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value27254526273651322780694942337544344077545645764039
Percentage of IncomeTaxExpenseBenefit29.632.357.287.332.453.577.946.333.461.745.735.726.926.248.235.823.334.153.544.036.637.060.852.027.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.21.22.11.41.11.82.21.81.24.33.52.82.01.93.72.51.72.44.03.02.22.44.12.41.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value109
Percentage of IncomeTaxExpenseBenefit11.611.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value31354327292741312827525353525749484946433837302045
Percentage of IncomeTaxExpenseBenefit34.045.254.790.435.339.563.145.133.920.834.438.834.041.736.539.533.441.532.335.024.930.623.726.232.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.41.72.01.51.21.31.81.71.21.42.63.02.53.02.82.82.42.92.42.41.52.01.61.22.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Taxes Paid Net

Profit Loss

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value336236320353102302902442722342592292622292652032451882342072541872351302371982111722301662094610197807211612610172
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.711.614.81.913.011.312.513.212.012.413.113.012.512.913.011.512.011.112.111.410.110.012.57.810.411.211.210.511.59.911.32.99.29.27.26.99.410.58.16.6

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value10094155899477140887712310877665211768546011881836911560
Percentage of ComprehensiveIncomeNetOfTax29.839.948.4252.330.333.648.435.928.352.541.633.625.223.044.233.522.232.250.639.432.737.149.046.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.44.67.24.83.93.86.14.73.46.55.44.43.13.05.73.92.73.66.14.53.33.76.13.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value3933
Percentage of ComprehensiveIncomeNetOfTax11.810.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1188311110411079100999899969190778683877180786987833779
Percentage of ComprehensiveIncomeNetOfTax35.335.434.8294.335.534.334.540.736.142.237.039.834.433.932.740.835.537.834.237.927.246.535.628.833.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.24.15.25.64.63.94.35.44.35.24.85.24.34.44.34.74.24.24.14.32.84.64.42.23.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value111111111111111111111-13111112111111111111
Percentage of ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1-0.70.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.10.1

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value336251320333102332912442712392622322612312672052461832372092552232361292371792111732291762094610011491781151311017387
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.712.314.81.813.011.512.513.111.912.613.213.212.413.013.111.612.010.912.311.510.211.912.57.710.410.111.210.611.510.511.32.89.210.78.27.59.410.98.26.66.5

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value100931548994771408777701087766521176854601188183691156058
Percentage of NetIncomeLoss29.837.148.3269.230.333.248.335.928.429.441.233.325.322.843.933.222.132.849.939.132.831.048.946.524.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.44.67.14.83.93.86.14.73.43.75.44.43.13.05.73.92.73.66.14.53.33.76.13.62.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value393340263214402535
Percentage of NetIncomeLoss11.813.312.880.710.66.114.010.512.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.61.91.41.40.71.81.41.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1188311110411079100999899969190778682877180786987833779
Percentage of NetIncomeLoss35.333.334.8314.435.633.934.440.836.341.436.739.234.533.732.440.335.438.833.737.627.139.035.528.933.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.24.15.25.64.63.94.35.44.35.24.85.24.34.44.24.74.24.24.14.32.84.64.42.23.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value33632033310291244271
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.714.81.813.012.513.111.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value10015489941408777
Percentage of NetIncomeLoss29.848.3269.230.348.335.928.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.47.14.83.96.14.73.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings es:NstarElectricCompany0.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value3932
Percentage of NetIncomeLoss11.810.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1181111041101009998
Percentage of NetIncomeLoss35.334.8314.435.634.440.836.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.25.25.64.64.35.44.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value33425031831308231289242269237260230259229265203244181235207253221234127235177209171228174207449911389771141291007186
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.612.214.71.712.911.412.513.011.812.513.113.112.312.913.011.511.910.712.211.410.111.812.47.610.310.011.110.511.410.411.22.79.010.68.17.49.210.78.16.56.4

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value442308435-145407298271288346
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic132.1123.4136.5-462.9132.0129.193.7119.0128.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax19.315.020.1-7.817.014.711.715.515.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment150.10.0168.6-58.1157.90.0120.7121.9149.8

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-450-314-421152-414-288-270-272-347-263-258-241-321-229-254-220-303-201-240
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic-134.7-125.7-132.2486.1-134.3-124.8-93.3-112.1-128.9-111.2-99.2-104.5-124.0-100.1-96.0-108.2-124.2-110.9-102.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-19.6-15.3-19.48.2-17.3-14.2-11.6-14.6-15.3-13.9-13.0-13.7-15.3-12.9-12.5-12.5-14.8-11.9-12.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:IntersegmentElimination79.90.076.9-31.879.70.052.254.772.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1309019710512076173101104
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic38.936.261.9335.138.932.960.141.738.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.74.49.15.65.03.77.55.44.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricDistribution7.40.010.36.86.60.08.46.56.0

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value126118107-8711897109112107
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic37.947.233.7-277.938.342.237.846.439.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.55.85.0-4.74.94.84.76.14.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceElectricTransmission37.30.029.2-30.736.00.029.835.933.9

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value28178041771
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic0.63.45.525.40.32.06.13.00.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.40.80.40.00.20.80.40.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:EversourceWater0.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value8438-17-17643-1255725-645025-785014-3
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic25.215.4-5.4-5.724.818.6-4.42.121.410.7-2.42.019.611.3-2.63.920.88.2-1.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.71.9-0.8-0.13.22.1-0.50.32.51.3-0.30.32.41.5-0.30.52.50.9-0.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments es:NaturalGasDistribution20.30.0-15.5-0.916.70.0-11.52.413.60.00.00.00.00.00.00.00.00.00.0

Net Income Loss Attributable To Noncontrolling Interest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1111111111111111111111111112111111111111
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.20.10.1

Assets

us-gaap:Assets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value416484112339725389953894138241375153724437039362203316332658323553205331082308823071230580300462987929951297772798227790280962779528444281962832828302277571597815647147281444214418144721429714229
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value12128118881149711253112361107010900107671076710536827880958014797277097663768276037437745474407333
Percentage of Assets29.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets29.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets es:NstarElectricCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value437843504127
Percentage of Assets10.510.610.8
Percentage of Assets10.510.610.8
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH100.0100.0100.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value124271218511926116991155411409112781108311146106301044510290101741003599189709966295929494940394169360
Percentage of Assets29.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets29.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets es:TheConnecticutLightAndPowerCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value208602046919137185501893917874
Percentage of Assets50.149.848.247.648.646.7
Percentage of Assets50.149.848.247.648.646.7
Percentage of Assets us-gaap:CorporateNonSegment100.0100.0100.0100.0100.0100.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value-20284-19488-18494-18004-18326-17464-16717-16571-16672-14430-13324-13002-12926-12862-12286-11781
Percentage of Assets-48.7-47.4-46.6-46.2-47.1-45.7-44.6-44.5-45.0-39.8-40.2-39.8-40.0-40.1-39.5-38.5
Percentage of Assets-48.7-47.4-46.6-46.2-47.1-45.7-44.6-44.5-45.0-39.8-40.2-39.8-40.0-40.1-39.5-38.5
Percentage of Assets us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value23135225412199921628215072138919250
Percentage of Assets55.554.855.455.555.255.953.1
Percentage of Assets55.554.855.455.555.255.953.1
Percentage of Assets us-gaap:OperatingSegments es:EversourceElectricDistribution100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value1113710904106661049910533102859401
Percentage of Assets26.726.526.926.927.026.926.0
Percentage of Assets26.726.526.926.927.026.926.0
Percentage of Assets us-gaap:OperatingSegments es:EversourceElectricTransmission100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value2368235123112290226822532182
Percentage of Assets5.75.75.85.95.85.96.0
Percentage of Assets5.75.75.85.95.85.96.0
Percentage of Assets us-gaap:OperatingSegments es:EversourceWater100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value4430434541034031401939043747365636363595343233373332330331493104
Percentage of Assets10.610.610.310.310.310.210.09.89.89.910.410.210.310.310.110.2
Percentage of Assets10.610.610.310.310.310.210.09.89.89.910.410.210.310.310.110.2
Percentage of Assets us-gaap:OperatingSegments es:NaturalGasDistribution100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value416484112339725389953894138241375153724437039362203316332658323553205331082308823071230580300462987929951297772798227790280962779528444281962832828302277571597815647147281444214472
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value12128118881149711253112361107010900107671076710536827880958014797277097663768276037437745474407333
Percentage of LiabilitiesAndStockholdersEquity29.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets29.128.928.928.928.928.929.128.929.129.125.024.824.824.924.824.825.024.924.824.924.824.6
Percentage of Assets es:NstarElectricCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value437843504127
Percentage of LiabilitiesAndStockholdersEquity10.510.610.8
Percentage of Assets10.510.610.8
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH100.0100.0100.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value124271218511926116991155411409112781108311146106301044510290101741003599189709966295929494940394169360
Percentage of LiabilitiesAndStockholdersEquity29.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets29.829.630.030.029.729.830.129.830.129.331.531.531.431.331.931.431.531.431.631.531.431.4
Percentage of Assets es:TheConnecticutLightAndPowerCompany100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value132091262912121119541163711486114081127311183110861099810885108041071110637105091043810352102941018510110997698909753972396119517940693459237917640684012395639153811
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.730.730.530.729.930.030.430.330.230.633.233.333.433.434.234.034.033.934.334.133.833.535.335.134.634.633.533.433.032.633.125.525.626.927.126.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value40634159391537513783373036953549345434462738272326902671259424522573260925982530249824632413
Percentage of StockholdersEquity30.832.932.331.432.532.532.431.530.931.124.925.024.924.924.423.324.725.225.224.824.724.725.1
Percentage of Assets9.810.19.99.69.79.89.89.59.39.58.38.38.38.38.37.98.48.58.68.58.38.38.7
Percentage of Assets es:NstarElectricCompany33.535.034.133.333.733.733.933.032.132.733.133.633.633.533.732.033.534.334.933.933.633.60.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value140913911316130213501387
Percentage of StockholdersEquity10.711.011.311.312.213.0
Percentage of Assets3.43.43.43.43.74.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH32.232.00.031.60.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value44344387418041364209419939213822363335873539355035093470338933543322314031192984295629362702
Percentage of StockholdersEquity33.634.734.534.636.236.634.433.932.532.432.232.632.532.431.931.931.830.330.329.329.229.428.1
Percentage of Assets10.610.710.510.610.811.010.510.39.89.910.710.910.810.810.910.910.810.310.410.09.99.99.7
Percentage of Assets es:TheConnecticutLightAndPowerCompany35.736.035.135.436.436.834.834.532.633.733.934.534.534.634.234.534.432.732.931.731.431.40.0

es:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings



Period End2020-01-01
Value-1
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings0.0

es:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents, dei:LegalEntity

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-01-01
Value-200000.0
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings es:NstarElectricCompany0.0

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-01-01
Value-300000.0
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings es:PublicServiceCompanyOfNewHampshirePSNH0.0

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-01-01
Value-900000.0
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings es:TheConnecticutLightAndPowerCompany0.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-312013-12-31
Value-63-65-52-53-57-60-59-60-63-66-63-62-62-65-65-65-66-74-46
Percentage of StockholdersEquity-0.5-0.5-0.4-0.4-0.5-0.5-0.5-0.5-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.7-0.5
Percentage of Assets-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value74797087667566596242624162346229622462396250626262356192
Percentage of StockholdersEquity56.656.155.155.753.654.354.655.355.756.358.360.562.564.4
Percentage of Assets18.017.216.817.116.016.316.616.716.817.219.520.520.922.3
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value17591729169916991669166916691669166916691669166916661665
Percentage of StockholdersEquity13.313.714.014.214.314.514.614.814.915.115.616.116.717.3
Percentage of Assets4.24.24.34.44.34.44.44.54.54.65.25.55.66.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value43224177410039544092395338823753367035613175279724482125
Percentage of StockholdersEquity32.733.133.833.135.234.434.033.332.832.129.627.024.522.1
Percentage of Assets10.410.210.310.110.510.310.310.19.99.89.99.18.27.6
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value-288-299-301-304-309-317-317-317-317-317-317-309-300-326
Percentage of StockholdersEquity-2.2-2.4-2.5-2.5-2.7-2.8-2.8-2.8-2.8-2.9-3.0-3.0-3.0-3.4
Percentage of Assets-0.7-0.7-0.8-0.8-0.8-0.8-0.8-0.9-0.9-0.9-1.0-1.0-1.0-1.2
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncome, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value00-1-1-1-1-1-1-1-1-1
Percentage of StockholdersEquity0.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets0.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value-1-1-2-2-3-5
Percentage of StockholdersEquity-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value315000.0316000.0325000.0326000.0318000.0301000.0306000.0318000.0309000.0269000.0-53000.0
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.0-0.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value18131813166316531653163316081603159515021500
Percentage of StockholdersEquity13.714.413.713.814.214.214.114.214.313.614.0
Percentage of Assets4.44.44.24.24.24.34.34.34.34.14.7
Percentage of Assets us-gaap:AdditionalPaidInCapital es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value903903678678843843
Percentage of StockholdersEquity6.87.25.85.97.67.9
Percentage of Assets2.22.21.71.82.32.6
Percentage of Assets us-gaap:AdditionalPaidInCapital es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value25352535241024102410241022102210211921102110
Percentage of StockholdersEquity19.220.119.920.220.721.019.419.619.019.019.7
Percentage of Assets6.16.26.16.26.26.35.95.95.75.86.6
Percentage of Assets us-gaap:AdditionalPaidInCapital es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value22492346225320992131209820881948186019441844
Percentage of StockholdersEquity17.018.618.617.618.318.318.317.316.617.517.2
Percentage of Assets5.45.75.75.45.55.55.65.25.05.45.8
Percentage of Assets us-gaap:RetainedEarnings es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value507490641627511549
Percentage of StockholdersEquity3.83.95.55.54.65.1
Percentage of Assets1.21.21.61.61.41.7
Percentage of Assets us-gaap:RetainedEarnings es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value18381791170816641737172716501551145214151299
Percentage of StockholdersEquity13.914.214.113.914.915.014.513.813.012.812.1
Percentage of Assets4.44.44.34.34.54.54.44.23.93.94.1
Percentage of Assets us-gaap:RetainedEarnings es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value256224142220213123002292215322772771248724032330251124772414241525902618236724492792269221012068236520872018205121582227213815231357132713371507
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.25.95.65.55.96.05.76.17.56.97.27.17.87.77.87.88.48.67.98.29.39.07.57.48.47.57.17.37.67.97.79.58.79.09.310.4

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value976855771709873836836804935887765661690707671701816772651746841745
Percentage of AssetsCurrent38.135.434.733.337.936.538.935.333.835.731.828.427.528.627.829.031.529.527.530.530.127.7
Percentage of Assets2.32.11.91.82.22.22.22.22.52.52.32.02.12.22.22.32.72.52.22.52.82.5
Percentage of Assets es:NstarElectricCompany8.17.26.76.37.87.67.77.58.78.49.28.28.68.98.79.110.610.28.810.011.310.2

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value306316357
Percentage of AssetsCurrent11.913.115.6
Percentage of Assets0.70.80.9
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH7.07.38.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value8867848367597947948047491069754880869912873935882938956920860916897
Percentage of AssetsCurrent34.632.537.735.634.534.737.332.938.630.336.637.336.335.238.736.636.236.538.935.132.833.3
Percentage of Assets2.11.92.11.92.02.12.12.02.92.12.72.72.82.73.02.93.13.13.12.93.13.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany7.16.47.06.56.97.07.16.89.67.18.48.49.08.79.49.19.710.09.79.29.79.6

Cash

us-gaap:Cash



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-312008-12-31
Value471522203510859643033812524453040385023353671384134894357366045732828361615152341882689
Percentage of Cash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.00.10.10.10.30.20.20.80.10.40.10.10.10.10.10.20.10.10.10.20.10.10.10.30.20.20.10.20.20.30.01.80.00.10.10.10.20.30.60.00.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value2000112091894236333221712111242813
Percentage of Cash6.00.31.20.95.01.54.10.23.14.671.518.25.311.615.48.86.914.07.97.825.233.026.538.147.218.529.9
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.30.00.00.00.00.00.00.00.00.00.10.00.00.00.10.00.0
Percentage of Assets es:NstarElectricCompany0.00.00.00.00.00.00.00.00.10.01.10.10.00.00.10.00.00.00.00.00.20.20.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value001
Percentage of Cash0.02.71.3
Percentage of Assets0.00.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value3092787112406951568916113916216101570
Percentage of Cash8.00.040.910.621.481.21.72.879.115.87.423.733.521.721.524.432.34.437.525.323.76.139.130.817.616.70.0
Percentage of Assets0.00.00.00.00.00.20.00.00.60.00.00.00.00.00.00.00.10.00.00.00.10.00.10.00.10.00.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.10.00.10.80.00.02.20.10.10.10.20.10.10.10.20.00.10.10.20.00.00.00.00.00.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value10189899939641140994109196710869259198338798479638068907759289031131856848807980765784789832792773485488494470523
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.42.42.52.52.92.62.92.62.92.62.82.62.72.63.12.62.92.53.13.03.82.93.02.93.52.82.82.82.92.82.83.03.13.43.33.6

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value375346385346400361457382406341322261264257300254256229303288317234
Percentage of AccountsReceivableNetCurrent36.935.138.835.935.136.341.939.537.436.935.031.330.130.431.231.528.829.732.831.928.127.4
Percentage of Assets0.90.81.00.91.00.91.21.01.10.91.00.80.80.81.00.80.80.81.01.01.10.8
Percentage of Assets es:NstarElectricCompany3.12.93.43.13.63.34.23.53.83.23.93.23.33.23.93.33.33.04.13.94.33.2

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value9999104
Percentage of AccountsReceivableNetCurrent9.810.110.5
Percentage of Assets0.20.20.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH2.32.32.5

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value389400428415443397466385411370404371349359425370379352425395449355
Percentage of AccountsReceivableNetCurrent38.240.543.143.138.939.942.839.837.940.143.944.539.842.444.246.042.645.545.943.839.741.5
Percentage of Assets0.91.01.11.11.11.01.21.01.11.01.21.11.11.11.41.21.21.21.41.31.51.2
Percentage of Assets es:TheConnecticutLightAndPowerCompany3.13.33.63.63.83.54.13.53.73.53.93.63.43.64.33.83.93.74.54.24.83.8

Inventory Raw Materials And Supplies

us-gaap:InventoryRawMaterialsAndSupplies



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value286235204174277238192171223
Percentage of InventoryRawMaterialsAndSupplies100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.60.50.40.70.60.50.50.6

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-312015-12-312014-12-31
Value1781249064160114665095627574
Percentage of InventoryRawMaterialsAndSupplies62.352.744.237.157.848.034.529.442.80.00.00.0
Percentage of Assets0.40.30.20.20.40.30.20.10.30.20.20.2
Percentage of Assets es:NstarElectricCompany1.51.00.80.61.41.00.60.50.90.81.01.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value282437
Percentage of InventoryRawMaterialsAndSupplies9.910.615.8
Percentage of Assets0.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.70.60.9

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value49505255524445555348445756525152484344504846
Percentage of InventoryRawMaterialsAndSupplies17.421.525.631.718.818.723.832.50.021.70.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.20.20.20.20.20.20.10.10.20.20.2
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.40.40.40.50.50.40.40.50.50.50.40.60.60.50.50.50.50.40.50.50.50.5

Other Assets Current

us-gaap:OtherAssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value2693423123021812602031072101381591571821341551061331291176223122613516829221422217410410711294107130100100
Percentage of OtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.80.80.80.50.70.50.30.60.40.50.50.60.40.50.30.40.40.40.20.80.80.50.61.00.80.80.60.40.40.40.60.70.90.70.7

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1631112124511858422416171714119131183710
Percentage of OtherAssetsCurrent6.19.13.77.013.619.98.954.120.117.810.311.39.411.17.18.910.48.97.56.23.44.8
Percentage of Assets0.00.10.00.10.10.10.00.20.10.10.00.10.10.00.00.00.00.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.10.30.10.20.20.50.20.50.40.20.20.20.20.20.10.10.20.20.10.10.10.1

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value61717
Percentage of OtherAssetsCurrent2.35.26.7
Percentage of Assets0.00.00.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.10.40.4

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value69732423206015205646131452321515493216155137
Percentage of OtherAssetsCurrent25.921.47.87.711.223.17.619.426.834.08.69.328.724.59.914.937.225.013.823.922.016.7
Percentage of Assets0.20.20.10.10.10.20.00.10.20.10.00.00.20.10.00.10.20.10.10.10.20.1
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.60.60.20.20.20.50.10.20.50.40.10.10.50.30.20.20.50.30.20.20.50.4

Property Plant And Equipment Net

Goodwill

us-gaap:Goodwill



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value4427442744274427442744274427442744274400351935193519350035193519351935193519351935193519351935193519351935193519351935193518287287287287287
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets10.610.811.111.411.411.611.811.912.012.110.610.810.910.911.311.411.511.511.711.811.811.812.612.712.512.712.412.512.412.412.71.81.82.02.02.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value544512606578463862664680646605627590556522344319299295324316329349347370504291279286311327300171172168152179
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.31.21.51.51.22.31.81.81.71.71.91.81.71.61.11.01.01.01.11.11.11.21.21.31.81.01.01.01.11.21.11.11.11.11.11.2

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1391441491421341091079386847971636011861586260585573
Percentage of OtherAssetsNoncurrent25.628.224.724.729.012.716.113.713.414.012.712.111.411.634.519.419.521.218.618.617.020.9
Percentage of Assets0.30.40.40.40.30.30.30.30.20.20.20.20.20.20.40.20.20.20.20.20.20.2
Percentage of Assets es:NstarElectricCompany1.11.21.31.31.21.01.00.90.80.81.00.90.80.81.50.80.80.80.80.80.81.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value414327
Percentage of OtherAssetsNoncurrent7.68.43.2
Percentage of Assets0.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.91.00.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value250217229221197199175172171159145138140137131121113111145146171177
Percentage of OtherAssetsNoncurrent46.042.537.838.442.623.226.425.326.526.323.223.425.226.438.038.137.737.644.746.251.950.7
Percentage of Assets0.60.50.60.60.50.50.50.50.50.40.40.40.40.40.40.40.40.40.50.50.60.6
Percentage of Assets es:TheConnecticutLightAndPowerCompany2.01.81.91.91.71.81.61.61.51.51.41.31.41.41.31.31.21.21.51.61.81.9

Liabilities Current

us-gaap:LiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value339536053748351245594112363035294096358926203785333336382642230325932989297128383111313429292802279032753378308138393643380019671947153514761345
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets8.28.89.49.011.710.89.79.511.19.97.911.610.311.48.57.58.49.89.99.510.410.510.510.19.911.811.910.913.612.913.712.312.410.410.29.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value10581135109610531440126711461160122110256367681120111662369386376610541140953878
Percentage of LiabilitiesCurrent31.231.529.230.031.630.831.632.929.828.624.320.333.630.723.630.133.325.635.540.230.628.0
Percentage of Assets2.52.82.82.73.73.33.13.13.32.81.92.43.53.52.02.22.82.53.53.83.23.0
Percentage of Assets es:NstarElectricCompany8.79.69.59.412.811.410.510.811.39.77.79.514.014.08.19.011.210.114.215.312.812.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value387352516
Percentage of LiabilitiesCurrent11.49.812.6
Percentage of Assets0.90.91.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH8.88.112.5

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value10308769909988349831151103913181092101811077611008104486190793577677711111074
Percentage of LiabilitiesCurrent30.324.326.428.418.323.931.729.532.230.438.929.322.827.739.537.435.031.326.127.435.734.3
Percentage of Assets2.52.12.52.62.12.63.12.83.63.03.13.42.43.13.42.83.03.12.62.63.73.6
Percentage of Assets es:TheConnecticutLightAndPowerCompany8.37.28.38.57.28.610.29.411.810.39.810.87.510.010.58.99.49.88.28.311.811.5

Long Term Debt Current

us-gaap:LongTermDebtCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value5323278537798058373873871097549957148377377337317837822822827824524524539553053360888894776387926733133433666
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.30.82.12.02.12.21.01.03.01.52.94.52.42.41.20.61.20.70.80.90.80.80.91.41.91.92.13.23.32.73.21.72.12.32.30.5

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value09595959500434004004000020020020020044
Percentage of LongTermDebtCurrent0.029.011.112.211.80.00.04.627.051.751.70.00.052.887.487.471.71.91.9
Percentage of Assets0.00.20.20.20.20.00.00.11.21.21.20.00.00.70.70.70.70.00.0
Percentage of Assets es:NstarElectricCompany0.00.80.80.80.80.00.00.54.95.05.00.00.02.62.62.72.70.10.1

Accounts Payable Current

us-gaap:AccountsPayableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value91411478929031006111996210109841085794587745884679631646813610598739868608561711742554532633764542412633476373417
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.22.82.22.32.62.92.62.72.73.02.41.82.32.82.22.02.12.72.02.02.52.92.22.02.52.71.91.92.22.72.02.64.03.22.62.9

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value264363304288306384296315329340198151177232194146189228172173233217
Percentage of AccountsPayableCurrent28.931.734.131.930.534.330.831.333.531.325.025.723.726.328.723.329.328.128.229.031.625.0
Percentage of Assets0.60.90.80.70.81.00.80.80.90.90.60.50.50.70.60.50.60.70.60.60.80.7
Percentage of Assets es:NstarElectricCompany2.23.12.62.62.73.52.72.93.13.22.41.92.22.92.51.92.53.02.32.33.13.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value103127111
Percentage of AccountsPayableCurrent11.311.19.9
Percentage of Assets0.20.30.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH2.42.92.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value331374280287347324347378346367292229281289228219246267207208230272
Percentage of AccountsPayableCurrent36.332.631.431.934.629.036.137.535.233.936.839.137.732.733.734.738.132.934.034.931.131.4
Percentage of Assets0.80.90.70.70.90.80.91.00.91.00.90.70.90.90.70.70.80.90.70.70.80.9
Percentage of Assets es:TheConnecticutLightAndPowerCompany2.73.12.42.53.02.83.13.43.13.52.82.22.82.92.32.32.62.82.22.22.42.9

Taxes Payable Current

Accrued Income Taxes Current

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value611836806677840823616662759738530591639684526472381678563595546828629580713702648650671744678369176139121167
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.52.02.01.72.22.21.61.82.02.01.61.82.02.11.71.51.22.21.92.01.82.82.22.12.52.52.32.32.42.62.42.31.10.90.81.2

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value687111261527411361577958485471565858728886116115
Percentage of OtherLiabilitiesCurrent11.28.514.09.16.29.118.49.37.610.811.18.28.510.410.812.415.410.615.814.621.314.0
Percentage of Assets0.20.20.30.20.10.20.30.20.20.20.20.10.20.20.20.20.20.20.30.30.40.4
Percentage of Assets es:NstarElectricCompany0.60.61.00.50.50.71.00.60.50.80.70.60.70.90.70.80.80.91.21.21.61.6

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value393244
Percentage of OtherLiabilitiesCurrent6.53.95.4
Percentage of Assets0.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.90.81.1

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value15213216914771161152119264127991431271209412211811012497207153
Percentage of OtherLiabilitiesCurrent24.915.821.021.88.519.624.718.134.817.218.824.420.017.618.026.031.116.322.116.338.018.5
Percentage of Assets0.40.30.40.40.20.40.40.30.70.40.30.40.40.40.30.40.40.40.40.30.70.5
Percentage of Assets es:TheConnecticutLightAndPowerCompany1.21.11.41.30.61.41.31.12.41.21.01.41.31.21.01.31.21.21.31.02.21.6

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

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



Period End2020-03-312019-12-31
Value38
Percentage of OtherLiabilitiesCurrent0.51.0
Percentage of Assets0.00.0
Percentage of Assets us-gaap:VariableInterestEntityPrimaryBeneficiary es:OtherRegulatoryAssets es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

Liabilities Noncurrent

Long Term Debt

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis

us-gaap:LongTermDebt

us-gaap:FairValueInputsLevel2, us-gaap:EstimateOfFairValueFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value151771517015479146391351913154125171250113376128771196810935104289980104549425
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets36.436.939.037.534.734.433.433.636.135.636.133.532.231.133.630.8
Percentage of Assets us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

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



Period End2020-03-312019-12-312019-09-302019-06-302018-12-31
Value39013659369535993024
Percentage of LongTermDebt25.724.123.924.623.0
Percentage of Assets9.48.99.39.27.9
Percentage of Assets us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure es:NstarElectricCompany0.00.00.00.00.0

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



Period End2020-03-312019-12-31
Value9951005
Percentage of LongTermDebt6.66.6
Percentage of Assets2.42.4
Percentage of Assets us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

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



Period End2020-03-312019-12-312019-09-302019-06-302018-12-31
Value39494058410437243429
Percentage of LongTermDebt26.026.726.525.426.1
Percentage of Assets9.59.910.39.69.0
Percentage of Assets us-gaap:FairValueInputsLevel2 us-gaap:EstimateOfFairValueFairValueDisclosure es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312016-12-312015-12-31
Value14431140981429313818130891308612538123961232596039034
Percentage of LongTermDebt95.192.992.394.496.899.5100.299.295.796.295.8
Percentage of Assets34.634.336.035.433.634.233.433.334.030.029.5
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:FairValueByMeasurementBasis, dei:LegalEntity

us-gaap:CarryingReportedAmountFairValueDisclosure, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302018-12-31
Value36423342334133412944
Percentage of LongTermDebt24.022.021.622.822.4
Percentage of Assets8.78.18.48.67.7
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure es:NstarElectricCompany0.00.00.00.00.0

us-gaap:CarryingReportedAmountFairValueDisclosure, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value951951805
Percentage of LongTermDebt6.36.36.1
Percentage of Assets2.32.32.1
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.0

us-gaap:CarryingReportedAmountFairValueDisclosure, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302018-12-31
Value35183518351833093254
Percentage of LongTermDebt23.223.222.722.624.7
Percentage of Assets8.48.68.98.58.5
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure es:TheConnecticutLightAndPowerCompany0.00.00.00.00.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value13898137701344013039122841224812151120091201511775104688899926788299235943591448805875786898602860681668147831877767444765170117200673249774614461443564632
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets33.433.533.833.431.532.032.432.232.432.531.627.228.627.529.730.629.828.829.129.128.728.929.229.329.628.026.227.124.825.424.331.129.531.330.232.0

Deferred Tax Liabilities Noncurrent

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312010-12-31
Value1331137082195593996210131044102612289461073107711411116129413551407149816361605163878782589089618081956209721302015124113261050
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.23.32.12.42.42.52.72.82.83.42.93.33.33.63.64.24.44.65.05.55.45.52.83.03.23.26.46.97.47.57.37.88.57.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value9510820295146178089391119911191194188209211220228235
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent7.27.92.53.10.61.50.61.77.87.34.210.49.29.88.215.013.914.914.113.414.214.4
Percentage of Assets0.20.30.10.10.00.00.00.00.20.20.10.30.30.30.30.60.60.70.70.70.80.8
Percentage of Assets es:NstarElectricCompany0.80.90.20.30.00.10.10.20.70.90.51.41.21.41.22.52.52.82.83.03.13.2

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value152157124
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent11.511.512.9
Percentage of Assets0.40.40.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH3.53.63.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value385391248275279282301306266354297301296300274247267271284286272273
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent28.928.530.328.829.829.429.829.326.028.931.428.127.526.324.619.119.819.319.017.517.016.7
Percentage of Assets0.91.00.60.70.70.70.80.80.71.00.90.90.90.90.90.80.90.90.91.00.90.9
Percentage of Assets es:TheConnecticutLightAndPowerCompany3.13.22.12.42.42.52.72.82.43.32.82.92.93.02.82.52.82.83.03.02.92.9

Minority Interest

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value82181012901264125911961094106910531073881860848853875875869871872875870874863882871923897899873967871414420671696695
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.02.03.23.23.23.12.92.92.83.02.72.62.62.72.82.82.82.82.92.92.92.93.13.23.13.33.23.23.13.43.12.62.74.64.84.8

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value334320325297293263219209197198135130125123125124123120122123126129
Percentage of OtherLiabilitiesNoncurrent40.739.625.223.523.322.020.019.618.718.515.415.114.814.414.314.314.213.914.014.114.514.8
Percentage of Assets0.80.80.80.80.80.70.60.60.50.50.40.40.40.40.40.40.40.40.40.40.40.4
Percentage of Assets es:NstarElectricCompany2.82.72.82.62.62.42.01.91.81.91.61.61.61.51.61.61.61.61.61.71.71.8

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value363736
Percentage of OtherLiabilitiesNoncurrent4.44.63.0
Percentage of Assets0.10.10.1
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH0.80.90.9

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value149147149153165155130119124128134125123123130131131133143144150148
Percentage of OtherLiabilitiesNoncurrent18.218.211.612.213.113.011.911.211.811.915.314.614.614.414.915.115.215.316.516.617.317.0
Percentage of Assets0.40.40.40.40.40.40.30.30.30.40.40.40.40.40.40.40.40.40.50.50.50.5
Percentage of Assets es:TheConnecticutLightAndPowerCompany1.21.21.31.31.41.41.21.11.11.21.31.21.21.21.31.41.41.41.51.51.61.6

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value132091262912121119541163711486114081127311183110861099810885108041071110637105091043810352102941018510110997698909753972396119517940693459237917640684012395639153811
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.730.730.530.729.930.030.430.330.230.633.233.333.433.434.234.034.033.934.334.133.833.535.335.134.634.633.533.433.032.633.125.525.626.927.126.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value40634159391537513783373036953549345434462738272326902671259424522573260925982530249824632413
Percentage of StockholdersEquity30.832.932.331.432.532.532.431.530.931.124.925.024.924.924.423.324.725.225.224.824.724.725.1
Percentage of Assets9.810.19.99.69.79.89.89.59.39.58.38.38.38.38.37.98.48.58.68.58.38.38.7
Percentage of Assets es:NstarElectricCompany33.535.034.133.333.733.733.933.032.132.733.133.633.633.533.732.033.534.334.933.933.633.60.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value140913911316130213501387
Percentage of StockholdersEquity10.711.011.311.312.213.0
Percentage of Assets3.43.43.43.43.74.3
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH32.232.00.031.60.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value44344387418041364209419939213822363335873539355035093470338933543322314031192984295629362702
Percentage of StockholdersEquity33.634.734.534.636.236.634.433.932.532.432.232.632.532.431.931.931.830.330.329.329.229.428.1
Percentage of Assets10.610.710.510.610.811.010.510.39.89.910.710.910.810.810.910.910.810.310.410.09.99.99.7
Percentage of Assets es:TheConnecticutLightAndPowerCompany35.736.035.135.436.436.834.834.532.633.733.934.534.534.634.234.534.432.732.931.731.431.40.0

es:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings



Period End2020-01-01
Value-1
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings0.0

es:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents, dei:LegalEntity

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-01-01
Value-200000.0
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings es:NstarElectricCompany0.0

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-01-01
Value-300000.0
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings es:PublicServiceCompanyOfNewHampshirePSNH0.0

es:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-01-01
Value-900000.0
Percentage of StockholdersEquity0.0
Percentage of Assets0.0
Percentage of Assets es:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:RetainedEarnings es:TheConnecticutLightAndPowerCompany0.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312014-12-312013-12-31
Value-63-65-52-53-57-60-59-60-63-66-63-62-62-65-65-65-66-74-46
Percentage of StockholdersEquity-0.5-0.5-0.4-0.4-0.5-0.5-0.5-0.5-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.6-0.7-0.5
Percentage of Assets-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value74797087667566596242624162346229622462396250626262356192
Percentage of StockholdersEquity56.656.155.155.753.654.354.655.355.756.358.360.562.564.4
Percentage of Assets18.017.216.817.116.016.316.616.716.817.219.520.520.922.3
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value17591729169916991669166916691669166916691669166916661665
Percentage of StockholdersEquity13.313.714.014.214.314.514.614.814.915.115.616.116.717.3
Percentage of Assets4.24.24.34.44.34.44.44.54.54.65.25.55.66.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value43224177410039544092395338823753367035613175279724482125
Percentage of StockholdersEquity32.733.133.833.135.234.434.033.332.832.129.627.024.522.1
Percentage of Assets10.410.210.310.110.510.310.310.19.99.89.99.18.27.6
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value-288-299-301-304-309-317-317-317-317-317-317-309-300-326
Percentage of StockholdersEquity-2.2-2.4-2.5-2.5-2.7-2.8-2.8-2.8-2.8-2.9-3.0-3.0-3.0-3.4
Percentage of Assets-0.7-0.7-0.8-0.8-0.8-0.8-0.8-0.9-0.9-0.9-1.0-1.0-1.0-1.2
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncome, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value00-1-1-1-1-1-1-1-1-1
Percentage of StockholdersEquity0.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets0.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value-1-1-2-2-3-5
Percentage of StockholdersEquity-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value315000.0316000.0325000.0326000.0318000.0301000.0306000.0318000.0309000.0269000.0-53000.0
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.0-0.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value18131813166316531653163316081603159515021500
Percentage of StockholdersEquity13.714.413.713.814.214.214.114.214.313.614.0
Percentage of Assets4.44.44.24.24.24.34.34.34.34.14.7
Percentage of Assets us-gaap:AdditionalPaidInCapital es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value903903678678843843
Percentage of StockholdersEquity6.87.25.85.97.67.9
Percentage of Assets2.22.21.71.82.32.6
Percentage of Assets us-gaap:AdditionalPaidInCapital es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value25352535241024102410241022102210211921102110
Percentage of StockholdersEquity19.220.119.920.220.721.019.419.619.019.019.7
Percentage of Assets6.16.26.16.26.26.35.95.95.75.86.6
Percentage of Assets us-gaap:AdditionalPaidInCapital es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value22492346225320992131209820881948186019441844
Percentage of StockholdersEquity17.018.618.617.618.318.318.317.316.617.517.2
Percentage of Assets5.45.75.75.45.55.55.65.25.05.45.8
Percentage of Assets us-gaap:RetainedEarnings es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value507490641627511549
Percentage of StockholdersEquity3.83.95.55.54.65.1
Percentage of Assets1.21.21.61.61.41.7
Percentage of Assets us-gaap:RetainedEarnings es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value18381791170816641737172716501551145214151299
Percentage of StockholdersEquity13.914.214.113.914.915.014.513.813.012.812.1
Percentage of Assets4.44.44.34.34.54.54.44.23.93.94.1
Percentage of Assets us-gaap:RetainedEarnings es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1759172916991699166916691669166916691669166916691669166916691669166916691669166916681666166616661666166516651664166416621662981980980979978
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.24.24.34.44.34.44.44.54.54.65.05.15.25.25.45.45.45.55.65.65.65.66.06.05.96.05.95.95.95.96.06.16.36.76.86.8

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value432241774100395440923953388237533670356134743364328431753087296229002797274726442569244823512241223721252064196919141802173516981651158715461452
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets10.410.210.310.110.510.310.310.19.99.810.510.310.29.99.99.69.49.19.18.98.68.28.48.18.07.67.37.06.86.46.310.610.610.810.710.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value2249234622532099213120982088194818601944169016751645162515731456157716131603153415021468
Percentage of RetainedEarningsAccumulatedDeficit52.056.255.053.152.153.153.851.950.754.648.749.850.151.251.049.254.457.758.358.058.560.0
Percentage of Assets5.45.75.75.45.55.55.65.25.05.45.15.15.15.15.14.75.15.35.35.15.04.9
Percentage of Assets es:NstarElectricCompany18.519.719.618.719.019.019.218.117.318.520.420.720.520.420.419.020.521.221.620.620.220.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value507490627
Percentage of RetainedEarningsAccumulatedDeficit11.711.715.9
Percentage of Assets1.21.21.6
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH11.611.315.2

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1838179117081664173717271650155114521415136713781338129912721237120611701149111910911072
Percentage of RetainedEarningsAccumulatedDeficit42.542.941.742.142.543.742.541.339.639.839.441.040.840.941.241.841.641.841.842.342.543.8
Percentage of Assets4.44.44.34.34.54.54.44.23.93.94.14.24.14.14.14.03.93.83.83.73.63.6
Percentage of Assets es:TheConnecticutLightAndPowerCompany14.814.714.314.215.015.114.614.013.013.313.113.413.212.912.812.712.512.212.111.911.611.5

Treasury Stock Value

us-gaap:TreasuryStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value288299301304309317317317317317317317317317309-309-309-309-309-309-296-300-306-313-321-326-330-334-336-338-340-344-346-348-351-354
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.70.80.80.80.80.80.90.90.91.01.01.01.01.0-1.0-1.0-1.0-1.0-1.0-1.0-1.0-1.1-1.1-1.1-1.2-1.2-1.2-1.2-1.2-1.2-2.2-2.2-2.4-2.4-2.5

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value-63-65-52-53-57-60-59-60-63-66-63-62-62-65-65-65-65-66-73-72-72-74-4041444667697072646870554543
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.10.10.20.20.20.20.30.30.20.40.50.40.30.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value00-1-1-1-1-1-1-1-1000000000000
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-0.4-0.22.02.12.22.32.52.62.72.7-0.6-0.6-0.6-0.6-0.8-0.8-0.8-0.8-0.4-0.4-0.4-0.6
Percentage of Assets0.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets es:NstarElectricCompany0.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value-1-1-2
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax2.32.64.8
Percentage of Assets-0.0-0.0-0.0
Percentage of Assets es:PublicServiceCompanyOfNewHampshirePSNH-0.0-0.0-0.1

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value315000.0316000.0325000.0326000.0318000.0301000.0306000.0318000.0309000.0269000.0270000.0238000.0114000.0-53000.0-165000.0-309000.0-456000.0-576000.0-735000.0-748000.0-816000.0-931000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-0.5-0.5-0.6-0.6-0.6-0.5-0.5-0.5-0.5-0.4-0.4-0.4-0.20.10.30.50.70.91.01.01.11.3
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value42051457049642837670952017751258447143652467147849982486373481231507402493486407295473365475311881201313372249309
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.325.126.326.617.918.530.628.07.827.129.426.720.729.532.927.124.34.925.120.619.212.326.824.021.627.421.618.123.721.725.519.10.87.718.130.030.220.724.9

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value61111335114136206371661362252744133773996896154294-1322115129196191
Percentage of NetCashProvidedByUsedInOperatingActivities14.721.658.823.132.054.852.412.776.844.047.01.030.614.759.414.419.3187.760.6-3.745.96.725.648.738.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.75.415.56.15.710.116.03.66.011.913.80.36.44.319.63.94.79.215.2-0.88.80.86.911.78.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value5886
Percentage of NetCashProvidedByUsedInOperatingActivities13.920.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.53.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value13219418514719813618320364181269182171197184208221-12315113613312920717995
Percentage of NetCashProvidedByUsedInOperatingActivities31.437.932.629.746.336.425.839.136.435.346.138.739.337.627.543.544.2-149.731.236.427.855.940.944.719.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.58.67.98.36.77.910.92.89.613.610.38.211.19.111.810.8-7.37.87.55.36.911.010.74.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-717-822-858-671-922-684-558-667-479-1572-459-648-529-789-494-442-424-500-442-351-364-468-401-370-351-382-341-270-446-406-371-387-302-308-282-190-236-268-241
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-31.3-40.1-39.6-35.9-38.5-33.7-24.1-35.9-21.1-82.9-23.1-36.8-25.2-44.4-24.3-25.0-20.7-29.6-22.9-19.3-14.5-24.9-21.2-22.1-15.3-21.5-18.0-16.6-22.4-24.1-20.0-23.8-27.5-28.9-25.3-18.2-19.2-22.3-19.5

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-247-225-217-210-208-186-182-163-192-361-95-129-135-196-127-108-91-155-126-108-79-155-96-117-95
Percentage of NetCashProvidedByUsedInInvestingActivities34.527.425.431.322.627.332.724.540.223.020.920.025.624.925.924.521.531.028.530.821.933.224.031.727.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-10.8-11.0-10.0-11.2-8.7-9.2-7.9-8.8-8.5-19.1-4.8-7.4-6.4-11.1-6.3-6.1-4.4-9.2-6.5-6.0-3.2-8.3-5.1-7.0-4.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-88-64
Percentage of NetCashProvidedByUsedInInvestingActivities12.37.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.9-2.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-212-218-233-276-189-203-202-255-202-202-201-238-181-173-149-141-138-164-116-118-125-126-156-112-106
Percentage of NetCashProvidedByUsedInInvestingActivities29.626.527.241.120.529.736.338.342.112.943.936.734.322.030.332.032.532.926.333.634.527.138.930.530.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-9.3-10.6-10.7-14.8-7.9-10.0-8.7-13.7-8.9-10.7-10.2-13.5-8.6-9.8-7.3-8.0-6.7-9.7-6.0-6.5-5.0-6.7-8.3-6.7-4.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value313272272233393383-138-93578971-23156108254-175-48-48406-44-57-84234-97-87-96-118-44-49-1113-59-17957021682-123-1430-115
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax13.713.312.612.516.418.8-6.0-5.025.451.3-1.28.95.214.3-8.6-2.7-2.424.0-2.3-3.1-3.412.4-5.2-5.2-4.2-6.7-2.4-3.0-0.60.8-3.2-11.051.920.37.4-11.8-11.60.1-9.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value188113-1178671-20-186886347-931270116-26839-41-168107-136142-35-107-61
Percentage of NetCashProvidedByUsedInFinancingActivities60.141.6-43.237.218.3-5.3135.1-94.111.04.9396.481.40.945.9152.7-81.59.90.3383.2-187.7160.660.736.2123.163.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.25.5-5.44.73.0-1.0-8.14.72.82.5-4.77.20.06.6-13.22.2-0.20.1-8.75.9-5.47.5-1.9-6.4-2.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value13-45
Percentage of NetCashProvidedByUsedInFinancingActivities4.4-11.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.6-1.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value831354124-8915319-18637117-634618-25-36-73-67275-31-256-16-45-7219
Percentage of NetCashProvidedByUsedInFinancingActivities26.75.119.953.3-22.740.0-13.8198.464.21.8272.529.717.2-10.120.5152.6140.067.870.945.1-7.3-7.146.382.5-20.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.70.72.56.7-3.77.50.8-10.016.30.9-3.22.60.9-1.4-1.8-4.2-3.316.3-1.6-1.40.2-0.9-2.4-4.30.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value42051457049642837670952017751258447143652467147849982486373481231507402493486407295473365475311881201313372249309
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax18.325.126.326.617.918.530.628.07.827.129.426.720.729.532.927.124.34.925.120.619.212.326.824.021.627.421.618.123.721.725.519.10.87.718.130.030.220.724.9

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value61111335114136206371661362252744133773996896154294-1322115129196191
Percentage of NetCashProvidedByUsedInOperatingActivities14.721.658.823.132.054.852.412.776.844.047.01.030.614.759.414.419.3187.760.6-3.745.96.725.648.738.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.75.415.56.15.710.116.03.66.011.913.80.36.44.319.63.94.79.215.2-0.88.80.86.911.78.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value5886
Percentage of NetCashProvidedByUsedInOperatingActivities13.920.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax2.53.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value13219418514719813618320364181269182171197184208221-12315113613312920717995
Percentage of NetCashProvidedByUsedInOperatingActivities31.437.932.629.746.336.425.839.136.435.346.138.739.337.627.543.544.2-149.731.236.427.855.940.944.719.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.89.58.67.98.36.77.910.92.89.613.610.38.211.19.111.810.8-7.37.87.55.36.911.010.74.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value336251320333102332912442712392622322612312672052461832372092552232361292371792111732291762094610011491781151311017387
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.712.314.81.813.011.512.513.111.912.613.213.212.413.013.111.612.010.912.311.510.211.912.57.710.410.111.210.611.510.511.32.89.210.78.27.59.410.98.26.66.5

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value100931548994771408777701087766521176854601188183691156058
Percentage of NetIncomeLoss29.837.148.3269.230.333.248.335.928.429.441.233.325.322.843.933.222.132.849.939.132.831.048.946.524.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.44.67.14.83.93.86.14.73.43.75.44.43.13.05.73.92.73.66.14.53.33.76.13.62.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value393340263214402535
Percentage of NetIncomeLoss11.813.312.880.710.66.114.010.512.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.61.91.41.40.71.81.41.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1188311110411079100999899969190778682877180786987833779
Percentage of NetIncomeLoss35.333.334.8314.435.633.934.440.836.341.436.739.234.533.732.440.335.438.833.737.627.139.035.528.933.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.24.15.25.64.63.94.35.44.35.24.85.24.34.44.24.74.24.24.14.32.84.64.42.23.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value33632033310291244271
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax14.714.81.813.012.513.111.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value10015489941408777
Percentage of NetIncomeLoss29.848.3269.230.348.335.928.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.47.14.83.96.14.73.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings es:NstarElectricCompany0.00.00.00.00.00.00.0

us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value3932
Percentage of NetIncomeLoss11.810.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.71.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1181111041101009998
Percentage of NetIncomeLoss35.334.8314.435.634.440.836.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax5.25.25.64.64.35.44.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.0

Profit Loss

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value286240296258285285301235249234236182210199225167195150151243194231105106129108125174181143
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value211717141313121112
Percentage of DepreciationDepletionAndAmortization7.47.35.85.74.84.64.05.14.8

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-600000.0-600000.0-600000.0-600000.0-600000.0-500000.0-600000.0-600000.0-600000.0-500000.0-600000.0-500000.0-500000.0-600000.0-500000.0-500000.0-500000.0-500000.0-500000.0
Percentage of DepreciationDepletionAndAmortization-0.2-0.2-0.2-0.2-0.2-0.2-0.2-0.3-0.2-0.2-0.3-0.3-0.2-0.3-0.2-0.3-0.3-0.3-0.3

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value167133188150179185206135144
Percentage of DepreciationDepletionAndAmortization58.555.763.558.262.765.068.457.657.9

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value676564626160585756
Percentage of DepreciationDepletionAndAmortization23.627.221.724.121.521.019.324.222.7

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value111111121111111210
Percentage of DepreciationDepletionAndAmortization4.05.03.74.74.14.23.95.24.3

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value19121619201513192618151721171516151717
Percentage of DepreciationDepletionAndAmortization6.75.15.47.67.15.44.68.210.67.76.49.810.38.76.710.08.111.411.6

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value61-93-346970-93-362723-121-17742-62-196210-35024-34-36-2153-11-59113732-28-442440-21-11-123311-25
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-7-32-71114-11-18-8070-23-11-5947-26-3883-192-2126-51-6-2927-31
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet-11.435.0204.6163.9-16.319.5221.1254.1-101.19.8349.1673.6-5.5-11.2199.9135.0-193.0-6.6-2522.8104.5149.717.0138.052.7275.8

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-9-6
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet-14.7-9.2

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value21-4047-3640-5248-3723-5851-4632-4345-2322-2133-97-918-248
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet35.243.4-137.2-52.057.356.7-132.9-135.298.747.8-303.6-649.976.169.4-239.4-37.6221.960.43870.2-39.3-22.625.9-86.4-46.1-77.4

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value514229-102394520-92263218-75331718-662213128-68145348-7512417-28-17-10-3061729-42-418
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value543325-95464715-82373318-5932174-754021-4-311391333
Percentage of IncreaseDecreaseInInventories106.780.585.892.9117.8105.176.189.1138.8102.496.878.597.098.824.5113.3177.3161.7-33.7-382.6-19.864.325.07.8-4.8

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value30
Percentage of IncreaseDecreaseInInventories6.9-0.4

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-717-822-858-671-922-684-558-667-479-1572-459-648-529-789-494-442-424-500-442-351-364-468-401-370-351-382-341-270-446-406-371-387-302-308-282-190-236-268-241
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-31.3-40.1-39.6-35.9-38.5-33.7-24.1-35.9-21.1-82.9-23.1-36.8-25.2-44.4-24.3-25.0-20.7-29.6-22.9-19.3-14.5-24.9-21.2-22.1-15.3-21.5-18.0-16.6-22.4-24.1-20.0-23.8-27.5-28.9-25.3-18.2-19.2-22.3-19.5

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-247-225-217-210-208-186-182-163-192-361-95-129-135-196-127-108-91-155-126-108-79-155-96-117-95
Percentage of NetCashProvidedByUsedInInvestingActivities34.527.425.431.322.627.332.724.540.223.020.920.025.624.925.924.521.531.028.530.821.933.224.031.727.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-10.8-11.0-10.0-11.2-8.7-9.2-7.9-8.8-8.5-19.1-4.8-7.4-6.4-11.1-6.3-6.1-4.4-9.2-6.5-6.0-3.2-8.3-5.1-7.0-4.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-88-64
Percentage of NetCashProvidedByUsedInInvestingActivities12.37.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.9-2.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-212-218-233-276-189-203-202-255-202-202-201-238-181-173-149-141-138-164-116-118-125-126-156-112-106
Percentage of NetCashProvidedByUsedInInvestingActivities29.626.527.241.120.529.736.338.342.112.943.936.734.322.030.332.032.532.926.333.634.527.138.930.530.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-9.3-10.6-10.7-14.8-7.9-10.0-8.7-13.7-8.9-10.7-10.2-13.5-8.6-9.8-7.3-8.0-6.7-9.7-6.0-6.5-5.0-6.7-8.3-6.7-4.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value725782751703674638633644607705495623523617490437431546436377362486393375348383373311388390391386304327280231236276235
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2472252172102081861821641923619512913219612710891155125108791559511894
Percentage of PaymentsToAcquirePropertyPlantAndEquipment34.128.829.029.930.929.328.825.531.651.219.420.925.231.826.124.821.228.428.828.722.032.024.331.627.2

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value8864
Percentage of PaymentsToAcquirePropertyPlantAndEquipment12.29.5

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value212218233276189203202255202202201238181173149141147164116114127144150113107
Percentage of PaymentsToAcquirePropertyPlantAndEquipment29.327.931.039.428.131.932.039.733.328.740.838.234.728.130.632.334.130.126.830.435.229.638.230.231.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value596870475560413442
Percentage of PaymentsToAcquirePropertyPlantAndEquipment8.28.89.46.78.39.46.55.37.0

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value315243289292279243241239236
Percentage of PaymentsToAcquirePropertyPlantAndEquipment43.531.138.641.541.438.238.237.238.9

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value232300237217231193227269239
Percentage of PaymentsToAcquirePropertyPlantAndEquipment32.138.431.631.034.330.435.941.839.4

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value183828302034272119
Percentage of PaymentsToAcquirePropertyPlantAndEquipment2.54.93.84.43.15.44.43.33.1

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value9913212511587106957970887075648565525262
Percentage of PaymentsToAcquirePropertyPlantAndEquipment13.716.916.716.413.016.615.012.411.612.514.212.112.313.813.312.112.111.4

Payments To Acquire Investments

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value313272272233393383-138-93578971-23156108254-175-48-48406-44-57-84234-97-87-96-118-44-49-1113-59-17957021682-123-1430-115
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax13.713.312.612.516.418.8-6.0-5.025.451.3-1.28.95.214.3-8.6-2.7-2.424.0-2.3-3.1-3.412.4-5.2-5.2-4.2-6.7-2.4-3.0-0.60.8-3.2-11.051.920.37.4-11.8-11.60.1-9.3

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value188113-1178671-20-186886347-931270116-26839-41-168107-136142-35-107-61
Percentage of NetCashProvidedByUsedInFinancingActivities60.141.6-43.237.218.3-5.3135.1-94.111.04.9396.481.40.945.9152.7-81.59.90.3383.2-187.7160.660.736.2123.163.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax8.25.5-5.44.73.0-1.0-8.14.72.82.5-4.77.20.06.6-13.22.2-0.20.1-8.75.9-5.47.5-1.9-6.4-2.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value13-45
Percentage of NetCashProvidedByUsedInFinancingActivities4.4-11.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.6-1.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:PublicServiceCompanyOfNewHampshirePSNH0.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value831354124-8915319-18637117-634618-25-36-73-67275-31-256-16-45-7219
Percentage of NetCashProvidedByUsedInFinancingActivities26.75.119.953.3-22.740.0-13.8198.464.21.8272.529.717.2-10.120.5152.6140.067.870.945.1-7.3-7.146.382.5-20.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax3.70.72.56.7-3.77.50.8-10.016.30.9-3.22.60.9-1.4-1.8-4.2-3.316.3-1.6-1.40.2-0.9-2.4-4.30.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value75045475100009001500115012503003506000030050040075300450750250400330095040055000300245260122000
Percentage of ProceedsFromIssuanceOfLongTermDebt100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.0100.00.00.00.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value40000400000350000250000000300
Percentage of ProceedsFromIssuanceOfLongTermDebt53.30.00.040.00.00.00.028.00.00.00.062.50.00.00.00.00.00.075.0

us-gaap:ConsolidatedEntities, us-gaap:ShortTermDebtType

srt:ParentCompany, us-gaap:CommercialPaper



Period End2020-03-31
Value165
Percentage of ProceedsFromIssuanceOfLongTermDebt22.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-302010-12-312010-09-30
Value220550002501890710150425170015000200005016600200301758947936005710245000
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-30
Value9504000000000
Percentage of RepaymentsOfLongTermDebt43.10.094.10.00.00.00.00.0-0.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value0000250003000010001500000000
Percentage of RepaymentsOfLongTermDebt0.00.00.00.099.90.00.042.20.00.058.80.0100.00.00.00.00.00.00.0-0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

es:A5.10SeriesESeniorNotes, us-gaap:SeniorNotes, es:NstarElectricCompany



Period End2020-03-31
Value95
Percentage of RepaymentsOfLongTermDebt43.1
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:A5.10SeriesESeniorNotes us-gaap:SeniorNotes es:NstarElectricCompany0.0

es:NSTARGas4.46SeriesNFirstMortgageBonds, us-gaap:SeniorNotes, es:NSTARGasCompany



Period End2020-01-31
Value125
Percentage of RepaymentsOfLongTermDebt0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:NSTARGas4.46SeriesNFirstMortgageBonds us-gaap:SeniorNotes es:NSTARGasCompany0.0

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

es:YankeeGas4.87SeriesKFirstMortgageBonds, us-gaap:SeniorNotes, us-gaap:SubsequentEvent, es:YankeeGas



Period End2020-04-30
Value50
Percentage of RepaymentsOfLongTermDebt0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:YankeeGas4.87SeriesKFirstMortgageBonds us-gaap:SeniorNotes us-gaap:SubsequentEvent es:YankeeGas0.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-302010-12-312010-09-30
Value220550002501890710150425170015000200005016600200301758947936005710245000
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-30
Value9504000000000
Percentage of RepaymentsOfLongTermDebt43.10.094.10.00.00.00.00.0-0.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:NstarElectricCompany0.00.00.00.00.00.00.00.00.00.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302014-12-31
Value0000250003000010001500000000
Percentage of RepaymentsOfLongTermDebt0.00.00.00.099.90.00.042.20.00.058.80.0100.00.00.00.00.00.00.0-0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:TheConnecticutLightAndPowerCompany0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

es:A5.10SeriesESeniorNotes, us-gaap:SeniorNotes, es:NstarElectricCompany



Period End2020-03-31
Value95
Percentage of RepaymentsOfLongTermDebt43.1
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:A5.10SeriesESeniorNotes us-gaap:SeniorNotes es:NstarElectricCompany0.0

es:NSTARGas4.46SeriesNFirstMortgageBonds, us-gaap:SeniorNotes, es:NSTARGasCompany



Period End2020-01-31
Value125
Percentage of RepaymentsOfLongTermDebt0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:NSTARGas4.46SeriesNFirstMortgageBonds us-gaap:SeniorNotes es:NSTARGasCompany0.0

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

es:YankeeGas4.87SeriesKFirstMortgageBonds, us-gaap:SeniorNotes, us-gaap:SubsequentEvent, es:YankeeGas



Period End2020-04-30
Value50
Percentage of RepaymentsOfLongTermDebt0.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.0
Percentage of LongTermDebtAndCapitalLeaseObligations es:YankeeGas4.87SeriesKFirstMortgageBonds us-gaap:SeniorNotes us-gaap:SubsequentEvent es:YankeeGas0.0

Debt Instrument Interest Rate Stated Percentage

Effective Income Tax Rate Continuing Operations

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

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

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

Deferred Tax Liabilities

Deferred Tax Assets Net

Unrecognized Tax Benefits

Deferred Tax Assets Valuation Allowance

Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions

Operating Lease Right Of Use Asset

Cash And Cash Equivalents Period Increase Decrease

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value133117151167108209134121362851717812610667
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value966614141513221410215161512
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents6.85.44.33.813.87.011.410.86.217.159.820.112.714.518.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312019-03-312018-12-312017-12-312016-12-31
Value2036285225
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents15.331.326.625.22.65.6

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value8414711914524391291882
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents6.64.29.44.210.543.83.64.767.211.27.512.015.07.93.2

Proceeds From Repayments Of Short Term Debt

us-gaap:ProceedsFromRepaymentsOfShortTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-408522-16-1010829-157-123141-240304-20-38-173414-32-2-39114561-49-39927921986-299-225548-492-22817095215343287-107-52-78111-1
Percentage of ProceedsFromRepaymentsOfShortTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value77-17-135-2058938-207801331830-1744890-29318086-196-118161-86142-35194-103
Percentage of ProceedsFromRepaymentsOfShortTermDebt-19.0-3.3818.220.310.8-24.2167.757.1-55.460.1-0.0459.2-27.721.9901.5-7220.0-22.0-134.8-192.1-324.721.651.1-16.0224.934.6

es:AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal



Period End2020-03-31
Value20
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-31
Value0.0
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal0.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-31
Value1
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal6.4

es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value14
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal72.4

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

es:HardshipAccounts



Period End2020-03-31
Value11
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal58.1

es:RetailNonHardshipWholesaleandOtherReceivables



Period End2020-03-31
Value8
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal41.9

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity

es:HardshipAccounts, es:NstarElectricCompany



Period End2020-03-31
Value-3
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal-16.7

es:HardshipAccounts, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value12
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal63.5

es:RetailNonHardshipWholesaleandOtherReceivables, es:NstarElectricCompany



Period End2020-03-31
Value3
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal16.7

es:RetailNonHardshipWholesaleandOtherReceivables, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value1
Percentage of AccountsReceivableAllowanceForCreditLossDeferredExpenseReversal8.9

es:AmountofNaturalGasToBePurchasedUnderFuturesContracts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value3-240613150405-1
Percentage of AmountofNaturalGasToBePurchasedUnderFuturesContracts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:DerivativeInstrumentsGainLossRecognizedInRegulatoryAssetLiability



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-18-1-9-5-5018-3610-4-262-53-42-30-1-8-36-16-15-1511154
Percentage of DerivativeInstrumentsGainLossRecognizedInRegulatoryAssetLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:EnergyEfficiencyPrograms



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value14811813610514010612910113489129116146127149119137115132101146112118102138
Percentage of EnergyEfficiencyPrograms100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value68628465766289657495715967648461665967415548564048
Percentage of EnergyEfficiencyPrograms46.352.461.762.354.859.268.863.955.7106.955.451.446.150.756.851.748.352.051.241.037.842.548.039.234.8

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value96
Percentage of EnergyEfficiencyPrograms6.34.8

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value3531402025223018228373236364435383442334236413542
Percentage of EnergyEfficiencyPrograms23.926.429.319.618.521.123.318.217.09.229.227.625.028.229.829.727.829.832.233.329.232.734.934.430.8

es:EnvironmentalSiteQuantity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value55.0-1.00.0-1.059.00.01.01.058.01.00.0-2.060.0-2.00.0-1.064.00.0-1.00.065.0
Percentage of EnvironmentalSiteQuantity100.0100.00.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.00.0100.00.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value13.00.00.00.015.0-1.01.01.015.05.0-1.0-2.013.0-1.00.0-1.015.01.00.00.014.0
Percentage of EnvironmentalSiteQuantity23.6-0.00.0-0.025.40.0100.0100.025.9500.00.0100.021.750.00.0100.023.40.0-0.00.021.5

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-31
Value9.0
Percentage of EnvironmentalSiteQuantity16.4

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value15.00.00.00.015.01.00.00.014.00.00.00.014.00.00.00.014.00.0-1.0-1.016.0
Percentage of EnvironmentalSiteQuantity27.3-0.00.0-0.025.40.00.00.024.10.00.0-0.023.3-0.00.0-0.021.90.0100.00.024.6

us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

es:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityGainLossIncludedInRegulatoryAssetLiability

us-gaap:FairValueInputsLevel3, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1631-8-255918
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetLiabilityGainLossIncludedInRegulatoryAssetLiability100.0100.0100.0100.0100.0100.0100.0100.0

es:IncrementalCommonSharesAttributableToDilutiveEffectOfShareBasedPaymentArrangementsAndOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value747233.070579.0737972.0645450.0691489.042319.0607201.0540591.0
Percentage of IncrementalCommonSharesAttributableToDilutiveEffectOfShareBasedPaymentArrangementsAndOther100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LossContingenciesByNatureOfContingency

es:LossContingencyAmountAssociatedWithFirstComplaintRefunded

es:FERCROEFirstComplaint



Period End2020-03-312019-09-302019-06-302019-03-31
Value380038
Percentage of LossContingencyAmountAssociatedWithFirstComplaintRefunded100.00.00.0100.0

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es:FERCROEFirstComplaint, es:NstarElectricCompany



Period End2020-03-312019-09-30
Value130
Percentage of LossContingencyAmountAssociatedWithFirstComplaintRefunded35.20.0

es:FERCROEFirstComplaint, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-31
Value2
Percentage of LossContingencyAmountAssociatedWithFirstComplaintRefunded7.2

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Period End2020-03-312019-09-30
Value220
Percentage of LossContingencyAmountAssociatedWithFirstComplaintRefunded57.60.0

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es:LossContingencyAnnualDistributionRateIncrease

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Period End2020-05-012019-05-012018-05-01
Value243297
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us-gaap:LossContingenciesByNatureOfContingency

es:LossContingencyBaseROESubsequentlyAuthorizedbyFERCforFirstComplaintPeriodandProspectivelyFromOctober2014

es:FERCROEFirstSecondandThirdComplaints



Period End2020-03-312019-09-302019-06-302019-03-31
Value0.11140.00.00.1114
Percentage of LossContingencyBaseROESubsequentlyAuthorizedbyFERCforFirstComplaintPeriodandProspectivelyFromOctober2014100.00.00.0100.0

es:LossContingencyPercentageOfBaseROEReasonablyJustified



Period End2020-03-312019-09-302019-06-302019-03-312018-10-16
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Percentage of LossContingencyPercentageOfBaseROEReasonablyJustified100.00.00.0100.0100.0

es:LossContingencyPercentageOfIncentiveCapOnTotalROE



Period End2020-03-312019-09-30
Value0.13080.0
Percentage of LossContingencyPercentageOfIncentiveCapOnTotalROE100.00.0

us-gaap:LossContingenciesByNatureOfContingency

es:LossContingencyPercentageofROEforAnyIncentiveProject

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Period End2020-03-312019-12-312019-09-30
Value0.11740.00.0
Percentage of LossContingencyPercentageofROEforAnyIncentiveProject100.00.00.0

dei:LegalEntity

es:PensionSERPandPBOPExpenseNetofContributions

es:NstarElectricCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-31
Value4224-31092-51027-1512
Percentage of PensionSERPandPBOPExpenseNetofContributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Range, us-gaap:FairValueByFairValueHierarchyLevel

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-30
Value0.13-0.0050000000000000044-0.00500000000000000440.151-0.010000000000000009
Percentage of PercentageofExitPricePremiums100.0100.0100.0100.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.015-0.0049999999999999975-0.005000000000000001-0.0059999999999999980.0370.032-0.01
Percentage of PercentageofExitPricePremiums11.50.0100.0120.024.50.0100.0

srt:WeightedAverage, us-gaap:FairValueInputsLevel3



Period End2020-03-31
Value0.119
Percentage of PercentageofExitPricePremiums91.5

us-gaap:RetirementPlanType, dei:LegalEntity

es:RelatedIntercompanyAllocationsofDefinedBenefitExpense

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-400000.0-300000.0-300000.0-400000.0-200000.0-300000.0-300000.0-300000.0
Percentage of RelatedIntercompanyAllocationsofDefinedBenefitExpense100.0100.0100.0100.0100.0100.0100.0100.0

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Period End2020-03-312019-03-31
Value-200000.0-100000.0
Percentage of RelatedIntercompanyAllocationsofDefinedBenefitExpense50.050.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-400000.0-300000.0-200000.0-300000.0-100000.0-200000.0-300000.0-200000.0
Percentage of RelatedIntercompanyAllocationsofDefinedBenefitExpense100.0100.066.775.050.066.7100.066.7

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value11153111
Percentage of RelatedIntercompanyAllocationsofDefinedBenefitExpense-475.0-633.3-633.3-1325.0-1500.0-566.7-533.3-533.3

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Period End2020-03-312019-03-31
Value02
Percentage of RelatedIntercompanyAllocationsofDefinedBenefitExpense-150.0-1200.0

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value12257111
Percentage of RelatedIntercompanyAllocationsofDefinedBenefitExpense-475.0-666.7-666.7-1450.0-3900.0-533.3-500.0-500.0

es:RepaymentsOfRateReductionBonds



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2121030000
Percentage of RepaymentsOfRateReductionBonds100.0100.00.0100.00.00.00.0

dei:LegalEntity

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2130
Percentage of RepaymentsOfRateReductionBonds100.0100.0

es:UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value876714730620974696842653946580651549
Percentage of UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value242205300228330275383266332226294231
Percentage of UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed27.728.741.236.833.939.545.540.735.139.045.142.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value94113
Percentage of UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed10.711.6

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value374322299246319244314234301219259207
Percentage of UtilitiesOperatingExpensePurchasedPowerPurchasedTransmissionAndFuelUsed42.745.240.939.732.835.137.335.831.937.939.737.7

us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts



Period End2020-03-312019-06-30
Value126
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-06-30
Value126
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableRecoveries



Period End2020-03-31
Value3
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-31
Value1
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries51.5

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-31
Value100000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries3.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value800000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries24.2

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

es:HardshipAccounts



Period End2020-03-31
Value200000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries6.1

es:RetailNonHardshipWholesaleandOtherReceivables



Period End2020-03-31
Value3
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries93.9

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity

es:HardshipAccounts, es:NstarElectricCompany



Period End2020-03-31
Value0.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries0.0

es:HardshipAccounts, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value200000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries6.1

es:RetailNonHardshipWholesaleandOtherReceivables, es:NstarElectricCompany



Period End2020-03-31
Value1
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries51.5

es:RetailNonHardshipWholesaleandOtherReceivables, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value600000.0
Percentage of AllowanceForDoubtfulAccountsReceivableRecoveries18.2

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs



Period End2020-03-31
Value21
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-31
Value8
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs39.1

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-31
Value1
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs7.9

es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value7
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs34.0

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

es:HardshipAccounts



Period End2020-03-31
Value4
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs21.9

es:RetailNonHardshipWholesaleandOtherReceivables



Period End2020-03-31
Value16
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs78.1

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity

es:HardshipAccounts, es:NstarElectricCompany



Period End2020-03-31
Value400000.0
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs1.9

es:HardshipAccounts, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value3
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs17.7

es:RetailNonHardshipWholesaleandOtherReceivables, es:NstarElectricCompany



Period End2020-03-31
Value8
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs37.2

es:RetailNonHardshipWholesaleandOtherReceivables, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value3
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs16.3

us-gaap:AmortizationOfDeferredCharges



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value4911733870779236
Percentage of AmortizationOfDeferredCharges100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

us-gaap:AmortizationOfRegulatoryAsset

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2730272322111711616924934-22-7-5-5-15-115
Percentage of AmortizationOfRegulatoryAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2013
Percentage of AmortizationOfRegulatoryAsset74.560.5

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value6-263012353154152824341112823-29-5-22-748-3131929
Percentage of AmortizationOfRegulatoryAsset24.2-87.5111.453.4157.9282.3315.1128.8440.1152.1351.2435.5257.20.0243.4-75.2210.9238.7-1012.8102.6-868.061.1-87.0-1293.0191.1

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

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



Period End2020-03-312019-03-31
Value1010
Percentage of AmortizationOfRegulatoryAsset40.046.9

us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

us-gaap:BusinessCombinationConsiderationTransferred1

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Period End2020-02-26
Value1100
Percentage of BusinessCombinationConsiderationTransferred1100.0

us-gaap:CapitalExpendituresIncurredButNotYetPaid



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-30
Value27361-5-12336132-23127471135-48220971760125551831110533171087013109820-26271384612
Percentage of CapitalExpendituresIncurredButNotYetPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value7037-628354-8115961250292102611-7172116-3-628
Percentage of CapitalExpendituresIncurredButNotYetPaid25.660.7105.1-15.924.740.8430.037.121.785.119.10.613.522.05.244.29.3-13.89.223.819.831.1-102.9-37.625.8

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value3730
Percentage of CapitalExpendituresIncurredButNotYetPaid13.89.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value853-6-71213-7-61171927-1810451565230-144211-11736
Percentage of CapitalExpendituresIncurredButNotYetPaid31.16.0108.562.736.22.3395.0-21.742.926.620.337.747.352.828.911.441.953.7-6.515.438.321.3-52.9104.733.4

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Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value16-1558-10012-24027693-4719
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value20-802-978600
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect16.9-0.9-14.5-0.217.73.92.893.30.52.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-16-23
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect-98.023.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value37-4-800-2382343-910
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect22.8-47.0-7.379.5-6.498.984.63.719.953.9

us-gaap:CommonStockDividendsPerShareCashPaid



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.56750.5350.5350.5350.5050.5050.505
Percentage of CommonStockDividendsPerShareCashPaid100.0100.0100.0100.0100.0100.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value44136361818104-91738811610512814116550109141338-2328148378-68-41379777871681051267526338425210567
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value91607325-136223910312939-71532118-72041147-17-231
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es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value46
Percentage of DeferredIncomeTaxExpenseBenefit9.436.2

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1934311526-2221292916254759113958147-411019145-57-1659
Percentage of DeferredIncomeTaxExpenseBenefit45.024.99.47.284.025.224.429.732.925.016.019.833.935.923.236.041.443.4175.537.813.138.484.3376.843.2

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-2-2-2-1-2-2-2-1-2-2-2-2-2-4-30
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-49-35-35-35-35-38-35-35-36-33-33-33-33-31-31-31
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses2347.61681.01695.22225.01432.01465.41373.12231.21384.61540.91540.91356.01680.0787.51046.73477.8

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-700000.0-800000.0-800000.0-700000.0-900000.0-600000.0-500000.0-400000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses33.338.138.143.836.023.119.225.0

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Period End2020-03-312019-03-31
Value-100000.0-200000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses4.88.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-400000.0-300000.0-300000.0-300000.0-400000.0-400000.0-400000.0-400000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses19.014.314.318.816.015.415.425.0

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-13-11-11-11-9-10-10-10
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses633.3552.4561.9737.5376.0388.5388.5631.2

us-gaap:PensionPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-4-3
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses195.2140.0

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-10-6-6-6-8-7-7-7
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses476.2300.0300.0393.8324.0276.9273.1443.8

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-5-5-5-5-5-6-6-5-5-5-5-5-5-5-30
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value00001-12221111100
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-5.6-0.0-5.2-5.2-19.028.3-33.3-36.8-37.3-20.0-22.6-20.8-20.8-18.5-25.00.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-4-4-4-4-4-4-4-4
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit77.871.272.472.472.470.071.775.4

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value200000.0300000.0200000.0300000.0300000.0300000.0300000.0300000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-3.7-5.1-3.4-5.2-5.2-5.0-5.0-5.3

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value100000.0100000.00.00.0100000.00.0100000.0100000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-1.9-1.7-0.0-0.0-1.7-0.0-1.7-1.8

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value0.00.00.00.00.0300000.0200000.0200000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit-0.0-0.0-0.0-0.0-0.0-5.0-3.3-3.5

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value18161616161818161815161615151515
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value100919191929797979883838383797979
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets554.1549.1548.5545.8556.0537.4537.4586.2541.4525.8521.9521.9525.2509.0499.4506.4

us-gaap:RetirementPlanType, dei:LegalEntity

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value87777888
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets47.045.544.944.645.244.544.548.5

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value11
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets7.77.8

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value22222222
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets13.313.813.213.713.914.314.315.6

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value2524242424262626
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets142.5144.9144.9144.0147.0146.2146.2159.3

us-gaap:PensionPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value1110
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets62.462.0

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value2018181818191919
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets110.5108.4108.4107.7113.3106.6106.6116.2

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value6888877676667679
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value44555454544949494847474746464646
Percentage of DefinedBenefitPlanInterestCost726.2673.2676.5668.3669.1640.3639.0722.1636.8695.6694.1749.2643.1723.4618.7493.6

us-gaap:RetirementPlanType, dei:LegalEntity

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value12222222
Percentage of DefinedBenefitPlanInterestCost27.929.329.629.328.428.628.632.4

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value600000.0900000.0
Percentage of DefinedBenefitPlanInterestCost9.811.1

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value11111111
Percentage of DefinedBenefitPlanInterestCost19.719.519.819.518.518.219.522.1

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value912121211101010
Percentage of DefinedBenefitPlanInterestCost157.4151.2151.9150.0146.9141.6141.6160.3

us-gaap:PensionPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value46
Percentage of DefinedBenefitPlanInterestCost80.376.5

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value911111111101010
Percentage of DefinedBenefitPlanInterestCost155.7137.8140.7139.0142.0135.1136.4154.4

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-12-10-10-11-9-11-11-11-11-10-9-10-9-7-6-2
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value131415151881091116161616171717
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-103.9-143.3-148.5-137.3-186.6-74.6-87.7-84.3-101.8-162.0-163.6-159.4-168.8-234.2-298.3-773.9

us-gaap:RetirementPlanType, dei:LegalEntity

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-9-8-8-8-8-9-9-9
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost76.478.878.674.583.579.880.780.9

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-400000.0100000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost3.1-1.0

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-100000.0200000.0200000.0200000.0300000.00.00.00.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost0.8-1.9-1.9-1.8-3.1-0.0-0.0-0.0

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value13330-1-1-1
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-7.9-33.7-34.0-31.8-9.311.410.510.4

us-gaap:PensionPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value02
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost0.8-20.6

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value53445333
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-40.9-37.5-38.8-36.4-57.7-32.5-31.6-31.3

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value2121222222222333
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value19161616192020202217171718181818
Percentage of DefinedBenefitPlanServiceCost753.8847.4810.0894.4919.0824.0836.0828.0840.7729.2725.0725.0779.2613.3620.0603.2

us-gaap:RetirementPlanType, dei:LegalEntity

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value600000.0400000.0400000.0400000.0400000.0400000.0500000.0500000.0
Percentage of DefinedBenefitPlanServiceCost23.121.120.022.219.016.020.020.0

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value500000.0300000.0300000.0300000.0400000.0500000.0400000.0400000.0
Percentage of DefinedBenefitPlanServiceCost19.215.815.016.719.020.016.016.0

us-gaap:PensionPlansDefinedBenefit, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value33333444
Percentage of DefinedBenefitPlanServiceCost146.2189.5180.0200.0185.7172.0172.0172.0

us-gaap:PensionPlansDefinedBenefit, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value22
Percentage of DefinedBenefitPlanServiceCost84.6123.8

us-gaap:PensionPlansDefinedBenefit, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value54444555
Percentage of DefinedBenefitPlanServiceCost219.2231.6220.0244.4228.6208.0208.0208.0

us-gaap:Depreciation



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value2362282222192142072081992042021941891861831811761731701671631631581531521501471491591541491441448079757373727079
Percentage of Depreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value787674737271706470106565655535452514949484847474646
Percentage of Depreciation33.233.333.533.333.834.233.832.234.552.528.929.629.629.430.229.829.829.329.229.929.830.131.030.830.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2422
Percentage of Depreciation10.310.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value78777674736972696765636059585757565554525249464646
Percentage of Depreciation33.233.734.334.034.133.534.534.833.032.132.832.032.031.731.832.632.732.532.631.932.331.130.630.630.6

us-gaap:DividendsCommonStock



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312014-12-312014-09-30
Value1871731691691601601604960
Percentage of DividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.00.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-06-302019-03-312018-03-31
Value19612160161
Percentage of DividendsCommonStock104.871.435.7100.6

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2219
Percentage of DividendsCommonStock11.911.2

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-03-31
Value69661769960
Percentage of DividendsCommonStock37.138.3103.958.337.5

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value187173169169160160160
Percentage of DividendsCommonStock100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:RetainedEarnings, es:NstarElectricCompany



Period End2020-03-312019-06-302019-03-312018-03-31
Value19612160161
Percentage of DividendsCommonStock104.871.435.7100.6

us-gaap:RetainedEarnings, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2219
Percentage of DividendsCommonStock11.911.2

us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-03-31
Value69661769960
Percentage of DividendsCommonStock37.138.3103.958.337.5

us-gaap:DividendsPreferredStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value111111111
Percentage of DividendsPreferredStock100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1111111
Percentage of DividendsPreferredStock73.973.973.973.973.173.273.9

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:RetainedEarnings, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1111111
Percentage of DividendsPreferredStock73.973.973.973.973.173.273.9

us-gaap:EarningsPerShareBasicAndDiluted



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.010.980.10.970.730.910.760.850.750.820.720.820.830.640.770.570.740.650.80.690.740.40.750.560.660.540.720.550.660.150.560.640.510.440.640.730.570.410.49
Percentage of EarningsPerShareBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ExciseAndSalesTaxes



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value43394236453943354339403542374537423437334133353544353733383336303532353238343733
Percentage of ExciseAndSalesTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value35333931363340313534373133334233363035293328323035
Percentage of ExciseAndSalesTaxes82.485.293.487.480.485.593.388.582.086.793.889.180.387.194.589.685.388.993.988.978.886.092.987.880.2

us-gaap:FairValueByFairValueHierarchyLevel, dei:LegalEntity

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements

us-gaap:FairValueInputsLevel3, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value111111108888
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ForwardContractIndexedToIssuersEquityShares



Period End2020-03-262020-03-232019-12-302019-06-042019-06-30
Value4161111
Percentage of ForwardContractIndexedToIssuersEquityShares100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsAndOtherReceivables



Period End2020-03-312019-03-31
Value55155
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-03-31
Value6429
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables117.518.8

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-2-1
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables-5.1-0.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-03-31
Value2760
Percentage of IncreaseDecreaseInAccountsAndOtherReceivables50.638.8

us-gaap:IncreaseDecreaseInAccountsPayable



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-127172-1-142-13507-18-6115271-110-5710730-75-76142-5-168-5921443-166535714-40-8679-3113-190-47905-2915-6
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-532435-64-18504-60431895-114-19-1065-61-2663-3-672950-19-10786
Percentage of IncreaseDecreaseInAccountsPayable42.014.3-2744.145.1133.699.653.8326.5-70.111.8132.7103.733.0-9.4216.181.835.244.655.840.1-49.123.5-43.964.6160.1

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-1811
Percentage of IncreaseDecreaseInAccountsPayable14.2-86.8

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-27933-6975-6115-2-284962-46-16337-33-5334-34-205143-24-2
Percentage of IncreaseDecreaseInAccountsPayable21.454.4-247.349.1-556.0-122.0207.613.046.132.686.742.429.431.126.143.76.62.5-632.920.733.924.2101.114.5-5.3

dei:LegalEntity

us-gaap:IncreaseDecreaseInDueToRelatedParties

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value574
Percentage of IncreaseDecreaseInDueToRelatedParties100.0100.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value155-109-86-2261-452124-6969-10197-76-2815-22-161277-85-104562899-34564
Percentage of IncreaseDecreaseInDueToRelatedParties269.00.00.00.06540.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-9269-60133-126138-203127536-648-32113-11749-279352-16857-272349-8935922-29372131-8-5-1159-60-30-18699
Percentage of IncreaseDecreaseInIncomeTaxesReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-3252-413-2976-79142228-312-38113-95-11-33130-106-4-961825-44-21
Percentage of IncreaseDecreaseInIncomeTaxesReceivable34.975.668.32.923.354.839.011.4448.577.448.233.2120.6100.581.3-23.812.236.963.4-7.635.452.3-6.1-1444.1-35.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-6-17
Percentage of IncreaseDecreaseInIncomeTaxesReceivable6.613.9

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-4055-1321-4163-7242-4279-27-8-3273-51-3-141173-3635-158166-12-20-7
Percentage of IncreaseDecreaseInIncomeTaxesReceivable44.079.921.516.332.846.035.633.1-839.0216.142.5-105.8101.965.043.8-8.050.949.222.061.158.147.513.6-675.3-11.7

us-gaap:IncreaseDecreaseInRegulatoryAssetsAndLiabilities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value22205-56-4319155-15333-70233-100-29-56139-158-7782195-105-37110283-125-163090-7144-39233-28262850663-4423-22
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value17107-29-12-431-146-16-1781-53-3-413-105-431675-47-610397-91-57-6
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities78.252.351.829.6-22.520.195.7-48.825.034.853.013.47.710.066.555.920.238.645.018.493.134.572.735.2736.6

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2226
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities103.1140.3

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value3457-72-145452-3831879-61-2818102-73-297066-67-126783-44-5840
Percentage of IncreaseDecreaseInRegulatoryAssetsAndLiabilities153.427.8128.233.0284.333.725.391.8-12.634.061.698.1-33.073.346.638.784.834.064.332.560.929.535.635.8-4632.9

us-gaap:IncrementalCommonSharesAttributableToEquityForwardAgreements



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10100000
Percentage of IncrementalCommonSharesAttributableToEquityForwardAgreements100.0100.0100.0100.00.00.00.00.0

dei:LegalEntity

us-gaap:NumberOfReportableSegments

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value1.00.00.00.01.00.00.01.00.00.00.01.00.0
Percentage of NumberOfReportableSegments100.00.00.00.0100.00.00.0100.00.00.00.0100.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-31
Value1.0
Percentage of NumberOfReportableSegments100.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-31
Value1.00.00.00.01.00.00.01.00.00.00.01.00.0
Percentage of NumberOfReportableSegments100.00.00.00.0100.00.00.0100.00.00.00.0100.00.0

us-gaap:OperatingLeaseLeaseIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value11111
Percentage of OperatingLeaseLeaseIncome100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value700000.0700000.0700000.0700000.0600000.0
Percentage of OperatingLeaseLeaseIncome63.670.058.363.660.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-31
Value200000.0300000.0300000.0300000.0200000.0
Percentage of OperatingLeaseLeaseIncome18.230.025.027.320.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value000000000-1-10100101-2-10000000000000
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1000.00.02000.04000.06000.01000.0-1000.0-1000.0-4000.0-10000.0-18000.09000.016000.0
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax0.6-0.01.20.90.90.60.70.70.90.91.00.91.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value9000.038000.0
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax5.65.8

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value6000.0-3000.06000.015000.023000.02000.0-5000.0-4000.0-12000.0-37000.0-64000.033000.056000.01000.033000.036000.09000.048000.0-98000.0-43000.04000.04000.0-7000.07000.08000.0
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax3.82.93.63.43.51.13.72.82.73.43.43.43.44.33.53.43.43.63.53.43.05.53.23.23.3

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0030020-1-21-1-105-2-10-3501019
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value00200200-30-2-203000-350
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax0.00.086.70.0-0.0108.3-0.0-0.0134.60.0158.8173.30.075.0-0.025.00.0100.3-0.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0000000-1011101-2-1000000
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.013.3100.0100.0-8.3100.0100.0-34.6100.0-58.8-73.3100.025.0100.075.0100.0-0.3100.020.0100.0-0.5

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax



Period End2020-03-312019-09-302019-06-302019-03-31
Value229000.0367000.0262000.0316000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-09-302019-06-302019-03-31
Value109000.0109000.0109000.0110000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax47.629.741.634.8

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-31
Value-7000.0-7000.0-7000.0-6000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax-3.1-1.9-2.7-1.9

us-gaap:OtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value1-131420123-200300016-101-3312121211-8221
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value010000000000000000000
Percentage of OtherComprehensiveIncomeLossNetOfTax3.4-9.16.92.75.3-28.77.85.13.2-6.60.60.5-0.1-43.64.05.8-0.64.30.1-0.5-11.3

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value278000.0307000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax14.314.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-1000.0-9000.0-1000.08000.017000.0-5000.0-12000.09000.040000.0-1000.032000.0124000.0167000.0112000.0144000.0147000.0120000.0159000.013000.068000.0115000.0115000.0104000.0118000.0119000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax-0.10.1-0.10.20.81.2-0.90.41.20.0-4.7-15.65.333.4-56.9-77.87.22.4-0.917.87.2-0.37.84.27.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value11311130-21-1-104011-3412121
Percentage of OtherComprehensiveIncomeLossNetOfTax82.167.784.154.578.284.091.7-102.9289.731.8671.91005.353.971.6-52.9288.762.7101.782.471.158.598.3

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302017-09-30
Value200000.0300000.0300000.0300000.0400000.0500000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax10.318.57.213.628.4-73.5

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0000000-1011101-2-1000000
Percentage of OtherComprehensiveIncomeLossNetOfTax10.312.39.631.8-7.1-9.3-12.2279.4-113.454.1-395.3-582.012.019.4185.1-315.06.3-0.3-22.510.711.7-0.5

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312015-12-31
Value1142123-2006
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.099.8100.0100.0100.8101.2102.9108.199.4

us-gaap:StatementEquityComponents, dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncome, es:NstarElectricCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value67000.0112000.0114000.0117000.0110000.0109000.0106000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax3.46.92.75.37.85.13.2

us-gaap:AccumulatedOtherComprehensiveIncome, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value278000.0307000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax14.314.0

us-gaap:AccumulatedOtherComprehensiveIncome, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-1000.0-1000.08000.017000.0-12000.09000.040000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax-0.1-0.10.20.8-0.90.41.2

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value-113-1-3-10-1-1-2202001-104010-3412020111-8111
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0-10000000000000000000
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax-2.8-8.10.10.00.1-1.40.10.10.011.9-0.60.2-0.465.50.60.6-1.15.9-0.3-0.2-18.9

us-gaap:OtherNoncashIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-31
Value33104810037-17551954054524249385-16-14197-26-2156-7-1-752-1671-5126-2926-7-14-1-25
Percentage of OtherNoncashIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value127132881645121711332246-10-9062-6-21-9358-1-15
Percentage of OtherNoncashIncomeExpense4.9263.228.428.921.6-91.883.36.04.0-560.314.422.28.765.062.5107.361.263.864.325.4101.2-164.4-755.774.6205.1

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value31
Percentage of OtherNoncashIncomeExpense11.74.3

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2713263451322211115-52521719-62-4915-42-1214-74
Percentage of OtherNoncashIncomeExpense81.8129.354.934.415.7-78.441.3111.421.6-4979.2-10.248.35.634.950.3-116.9-13.434.915.817.9-10.7-22.3-190.2446.2-59.9

us-gaap:PaymentsForProceedsFromOtherInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-6-2550-4-30985-350011-4668-5147-40-1951-1-68028-274-17-20-2-19150-96
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-06-302015-03-312014-06-302014-03-31
Value0000000000003000000-10
Percentage of PaymentsForProceedsFromOtherInvestingActivities0.30.1-0.5-2.90.30.0-0.2-7.712.6-0.0-0.0-0.032.1-0.00.00.0-0.0-0.080.3-100.7-29.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-126000.0-102000.0
Percentage of PaymentsForProceedsFromOtherInvestingActivities2.12.1

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value00000000000000000003-1-1760-1
Percentage of PaymentsForProceedsFromOtherInvestingActivities1.20.3-1.8-58.71.20.1-0.6-0.6-1.10.16.143.3-0.3-0.0-1.6-1.80.9-0.2-8.2-70.33001.590.3116.5-51.862.7

us-gaap:PaymentsOfDividendsCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value18116717215316916016016016015015015015014114114114113213213213211911811811812110911511610710710752484848484545
Percentage of PaymentsOfDividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1960012160670016186934646001889049494949000253
Percentage of PaymentsOfDividendsCommonStock108.20.00.078.935.741.90.00.0100.657.161.830.930.9-0.00.0133.264.037.437.437.437.40.00.00.0213.6

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value2219
Percentage of PaymentsOfDividendsCommonStock12.311.2

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value690661769900060491064949494949494949494942424242
Percentage of PaymentsOfDividendsCommonStock38.30.038.6114.958.30.00.00.037.533.070.433.033.035.435.435.435.437.037.037.037.035.936.036.136.1

us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value111111111111111111111111111211111111111
Percentage of PaymentsOfDividendsPreferredStockAndPreferenceStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0490000.0491000.0490000.0490000.0490000.0
Percentage of PaymentsOfDividendsPreferredStockAndPreferenceStock26.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.126.1

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1111111111111111111111111
Percentage of PaymentsOfDividendsPreferredStockAndPreferenceStock73.973.973.973.973.973.973.973.973.973.973.973.973.973.973.973.973.973.973.973.974.073.973.973.974.0

us-gaap:PaymentsToAcquireEquityMethodInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value641108162491771457
Percentage of PaymentsToAcquireEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireMarketableSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value5013210265237512811711433041112441492441141861351821262911161011321241321381162401849510910141334434392951
Percentage of PaymentsToAcquireMarketableSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementBenefitContributions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-31
Value01113146971714410645453655353001314261363434632157547532-401263-9831-512
Percentage of PensionAndOtherPostretirementBenefitContributions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-30
Value01111115907671011
Percentage of PensionAndOtherPostretirementBenefitContributions0.0102.81.777.232.021.413.1762.50.017.163.528.720.2

us-gaap:PensionAndOtherPostretirementBenefitExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value13548015-1555588111124232126242622244849445358625542295117342949
Percentage of PensionAndOtherPostretirementBenefitExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value322242286-820240
Percentage of PensionAndOtherPostretirementBenefitExpense169.783.555.259.748.2767.6145.81630.84187.117.837.291.4-10.7

dei:LegalEntity

us-gaap:ProceedsFromContributionsFromParent

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-31
Value015010020255892001025250
Percentage of ProceedsFromContributionsFromParent0.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.00.0100.0100.00.0

us-gaap:ProceedsFromIssuanceOfCommonStock



Period End2020-03-262020-03-232020-03-312019-12-302019-12-312019-09-302019-06-042019-06-302019-03-312018-12-312018-09-30
Value3141054194254250426426000
Percentage of ProceedsFromIssuanceOfCommonStock100.0100.0100.0100.0100.00.0100.0100.00.00.00.0

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

us-gaap:ProceedsFromIssuanceOfDebt

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



Period End2020-01-31
Value350
Percentage of ProceedsFromIssuanceOfDebt100.0

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

srt:ParentCompany, es:A3.45SeriesPSeniorNotesDue2050, us-gaap:SeniorNotes, us-gaap:SubsequentEvent



Period End2020-01-31
Value350
Percentage of ProceedsFromIssuanceOfDebt100.0

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

es:A3.952020Debentures, us-gaap:SeniorNotes, es:NstarElectricCompany



Period End2020-03-31
Value400
Percentage of ProceedsFromIssuanceOfDebt0.0

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

es:NSTARGas2.33SeriesRFirstMortgageBonds, us-gaap:SeniorNotes, us-gaap:SubsequentEvent, es:NSTARGasCompany



Period End2020-05-31
Value75
Percentage of ProceedsFromIssuanceOfDebt0.0

es:NSTARGas3.15SeriesSFirstMortgageBonds, us-gaap:SeniorNotes, us-gaap:SubsequentEvent, es:NSTARGasCompany



Period End2020-05-31
Value115
Percentage of ProceedsFromIssuanceOfDebt0.0

dei:LegalEntity

us-gaap:ProceedsFromNotesPayable

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value8-1881822-1616000
Percentage of ProceedsFromNotesPayable100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-21010-1-9-8-21-19-419-3-15-160-2-13-43-6-103-1-2-11-1-9-2-6131-1-2-4-1010
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-400-30000010-3010-20-2000000-4
Percentage of ProceedsFromPaymentsForOtherFinancingActivities23.0-2.3-5.7393.1-6.9-4.33.4-6.80.4-29.0-0.391.20.2-11.1-0.084.4-0.059.20.00.1-0.50.10.012.3243.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value-22000.0-20000.0
Percentage of ProceedsFromPaymentsForOtherFinancingActivities0.10.2

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value008400-10-621-20-30000-10-8000-20
Percentage of ProceedsFromPaymentsForOtherFinancingActivities1.867.682.4-453.63.4-6.158.129.634.2-433.0-12.57.722.91.580.26.51.530.0-5.6140.86.0-32.5-3.6152.710.1

us-gaap:ProceedsFromSaleAndMaturityOfMarketableSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value581081091142344958917014531214621915421511619013624212831311410013212712813914524498841009140324433382850
Percentage of ProceedsFromSaleAndMaturityOfMarketableSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProvisionForDoubtfulAccounts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302012-12-312012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value1117141318102191914140123334467
Percentage of ProvisionForDoubtfulAccounts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-03-312015-03-312014-03-31
Value367551937680686
Percentage of ProvisionForDoubtfulAccounts32.638.147.043.832.117.442.340.038.344.156.2-133.30.00.00.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value01
Percentage of ProvisionForDoubtfulAccounts5.99.3

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value33434343333-4
Percentage of ProvisionForDoubtfulAccounts28.522.730.226.922.134.620.540.020.024.425.01566.7

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

es:HardshipAccounts



Period End2020-03-31
Value0.0
Percentage of ProvisionForDoubtfulAccounts0.0

es:RetailNonHardshipWholesaleandOtherReceivables



Period End2020-03-31
Value11
Percentage of ProvisionForDoubtfulAccounts100.4

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity

es:HardshipAccounts, es:NstarElectricCompany



Period End2020-03-31
Value0.0
Percentage of ProvisionForDoubtfulAccounts0.0

es:HardshipAccounts, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value0.0
Percentage of ProvisionForDoubtfulAccounts0.0

es:RetailNonHardshipWholesaleandOtherReceivables, es:NstarElectricCompany



Period End2020-03-31
Value3
Percentage of ProvisionForDoubtfulAccounts32.6

es:RetailNonHardshipWholesaleandOtherReceivables, es:TheConnecticutLightAndPowerCompany



Period End2020-03-31
Value3
Percentage of ProvisionForDoubtfulAccounts28.2

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value-1-2-1-1-1-1-10-3-2-1-1-1-1-1-1-1-1-1-2-1-1-1-1-1-2
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value-18-10-18-10-3-10-1-1-1-10000-1-1-1-10-1-1
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax88.9-303.478.675.080.0-476.573.3266.781.180.058.366.766.772.266.753.864.360.061.575.066.766.768.861.566.776.2

us-gaap:AccumulatedGainLossNetCashFlowHedgeParent



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302017-09-30
Value-200000.0-300000.0-300000.0-300000.0-400000.0-500000.0
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax11.121.425.020.026.741.7

us-gaap:RevenueNotFromContractWithCustomer



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value74280101414-55-11
Percentage of RevenueNotFromContractWithCustomer100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-27-2319-58-11-933-2
Percentage of RevenueNotFromContractWithCustomer-36.8-81.5-9500.0-582.2-75.5-66.7-61.224.4

us-gaap:ConsolidationItems, dei:LegalEntity

us-gaap:OperatingSegments, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value192292716-15-6
Percentage of RevenueNotFromContractWithCustomer25.978.4-4900.020.849.7114.627.958.0

us-gaap:OperatingSegments, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value41
Percentage of RevenueNotFromContractWithCustomer6.310.2

us-gaap:OperatingSegments, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value4431-155552-641
Percentage of RevenueNotFromContractWithCustomer59.9111.17600.0545.538.817.4116.5-8.4

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value383066210-51-14
Percentage of RevenueNotFromContractWithCustomer52.1107.7-3350.062.414.370.893.5121.0

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value2925-20641210-373
Percentage of RevenueNotFromContractWithCustomer40.089.510450.0639.684.470.167.0-28.6

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value32-4-7-2102-10
Percentage of RevenueNotFromContractWithCustomer43.2-17.13800.0-26.770.713.92.7-0.8

us-gaap:OperatingSegments, us-gaap:WaterDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value10200111
Percentage of RevenueNotFromContractWithCustomer1.51.4-1300.06.96.111.8-2.0-16.0

us-gaap:RevenueNotFromContractWithCustomerOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value45763655
Percentage of RevenueNotFromContractWithCustomerOther100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems, dei:LegalEntity

us-gaap:OperatingSegments, es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value11111311
Percentage of RevenueNotFromContractWithCustomerOther29.231.023.730.639.547.132.730.8

us-gaap:OperatingSegments, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value600000.0300000.0
Percentage of RevenueNotFromContractWithCustomerOther12.57.9

us-gaap:OperatingSegments, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value12421222
Percentage of RevenueNotFromContractWithCustomerOther35.441.453.943.526.329.450.946.2

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value34652544
Percentage of RevenueNotFromContractWithCustomerOther72.974.184.280.673.780.987.380.8

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value200000.0400000.0100000.0100000.00.00.00.00.0
Percentage of RevenueNotFromContractWithCustomerOther4.26.91.31.60.00.00.00.0

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value00000100
Percentage of RevenueNotFromContractWithCustomerOther18.813.810.514.518.416.210.915.4

us-gaap:OperatingSegments, us-gaap:WaterDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value200000.0300000.0300000.0200000.0300000.0200000.0100000.0200000.0
Percentage of RevenueNotFromContractWithCustomerOther4.25.23.93.27.92.91.83.8

us-gaap:StockIssuedDuringPeriodSharesNewIssues



Period End2020-03-312019-06-04
Value55
Percentage of StockIssuedDuringPeriodSharesNewIssues100.0100.0

us-gaap:StatementEquityComponents

us-gaap:CommonStock



Period End2020-03-312019-06-30
Value55
Percentage of StockIssuedDuringPeriodSharesNewIssues100.00.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesTreasuryStockReissued

us-gaap:CommonStock



Period End2020-03-312019-09-302019-06-302019-03-31
Value570542.0158984.0246969.0461662.0
Percentage of StockIssuedDuringPeriodSharesTreasuryStockReissued100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueNewIssues



Period End2020-03-312019-06-302014-12-312014-09-30
Value43243360
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.00.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-06-30
Value402403
Percentage of StockIssuedDuringPeriodValueNewIssues93.193.1

us-gaap:CommonStock



Period End2020-03-312019-06-30
Value2929
Percentage of StockIssuedDuringPeriodValueNewIssues6.96.9

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-1566-1644-15
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-1566-1644-15
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueTreasuryStockReissued



Period End2020-03-312019-09-302019-06-302019-03-31
Value27121826
Percentage of StockIssuedDuringPeriodValueTreasuryStockReissued100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-06-302019-03-31
Value17101317
Percentage of StockIssuedDuringPeriodValueTreasuryStockReissued62.178.574.666.9

us-gaap:TreasuryStock



Period End2020-03-312019-09-302019-06-302019-03-31
Value10248
Percentage of StockIssuedDuringPeriodValueTreasuryStockReissued37.921.525.433.1

us-gaap:TaxesExcludingIncomeAndExciseTaxes



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1811731711811841821871771821971681561551541641541591511501381491391411341451201351231321141201128670847988708474
Percentage of TaxesExcludingIncomeAndExciseTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value48515148444849474882373427343534323734293033343232
Percentage of TaxesExcludingIncomeAndExciseTaxes26.829.629.826.624.326.626.726.826.442.022.022.217.622.621.222.220.424.723.221.520.724.324.424.122.1

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value1917
Percentage of TaxesExcludingIncomeAndExciseTaxes10.89.4

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value828182869289928490100797073718170756671626861646266
Percentage of TaxesExcludingIncomeAndExciseTaxes45.746.948.147.749.849.049.647.649.550.947.045.147.746.349.745.747.244.247.544.745.543.945.946.146.0

us-gaap:UtilitiesOperatingExpenseMaintenanceAndOperations



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-30
Value342368331328335364344293332343300302330357324320320351327316333358344373351425386357346395395529261306255
Percentage of UtilitiesOperatingExpenseMaintenanceAndOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value1221251201081121171231021181979285881139688947783697582797885
Percentage of UtilitiesOperatingExpenseMaintenanceAndOperations35.834.136.533.233.732.335.934.835.757.530.828.226.831.629.627.729.622.125.521.922.723.023.221.224.4

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-03-31
Value4752
Percentage of UtilitiesOperatingExpenseMaintenanceAndOperations13.815.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value135150135133130150128109117140123108128133123122110128122118117126127131109
Percentage of UtilitiesOperatingExpenseMaintenanceAndOperations39.640.740.840.738.941.437.337.335.340.941.035.838.837.337.938.234.636.637.437.535.235.137.035.331.1

us-gaap:UtilitiesOperatingExpenseOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1548137413701235163513491504122715961210124911251385113913041176137211551312133211581217779777781761882834862790
Percentage of UtilitiesOperatingExpenseOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value257171275218225214200211204
Percentage of UtilitiesOperatingExpenseOther16.612.520.117.713.815.913.417.312.8

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value-591-435-638-538-531-509-483-501-471-272-220-241-252-241-199-230-220-212-198
Percentage of UtilitiesOperatingExpenseOther-38.2-31.7-46.6-43.6-32.5-37.8-32.2-40.9-29.6-22.5-17.6-21.4-18.2-21.2-15.3-19.6-16.1-18.4-15.1

us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, es:EversourceElectricDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value143913581448124314751310156212331443
Percentage of UtilitiesOperatingExpenseOther93.098.8105.7100.690.297.1103.9100.590.4

us-gaap:OperatingSegments, es:EversourceElectricTransmission



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value1064415910898106968883
Percentage of UtilitiesOperatingExpenseOther6.93.211.68.86.07.96.47.25.2

us-gaap:OperatingSegments, es:EversourceWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value252525252525252423
Percentage of UtilitiesOperatingExpenseOther1.61.91.92.01.51.91.72.01.5

us-gaap:OperatingSegments, es:NaturalGasDistribution



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-30
Value31121099179341201102170312178951502891668714123314592
Percentage of UtilitiesOperatingExpenseOther20.115.37.214.520.915.06.813.919.614.77.613.320.914.66.712.017.012.67.1

us-gaap:WeightedAverageNumberDilutedSharesOutstandingAdjustment



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value110000000000000111100000000000
Percentage of WeightedAverageNumberDilutedSharesOutstandingAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:EntityCommonStockSharesOutstanding



Period End2020-04-302020-01-312019-10-312019-07-312019-04-302019-01-312018-10-312018-07-312018-04-302018-01-312017-10-312017-07-312017-04-302017-01-312016-10-31
Value336329323323317316316316316316316316316316316
Percentage of EntityCommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-04-302020-01-312019-10-312019-07-312019-04-302019-01-312018-10-312018-07-312018-04-302018-01-312017-10-312017-07-312017-04-302017-01-312016-10-31
Value200.0200.0200.0200.0200.0200.0200.0200.0200.0200.0100.0100.0100.0100.0100.0
Percentage of EntityCommonStockSharesOutstanding0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

es:AmountofCapacityProvidedUnderCapacityContract



Period End2020-03-312019-12-312019-09-302019-06-302018-12-312017-09-302017-06-302017-03-312016-12-31
Value676.0676.0679.0679.0787.00.00.0787.00.0
Percentage of AmountofCapacityProvidedUnderCapacityContract100.0100.0100.0100.0100.00.00.0100.00.0

us-gaap:SubsequentEventType, dei:LegalEntity

es:DebtInstrumentAuthorizedAmountAvailableForIssuance

us-gaap:SubsequentEvent, es:NSTARGasCompany



Period End2020-01-27
Value270
Percentage of DebtInstrumentAuthorizedAmountAvailableForIssuance100.0

es:ElectricAndNaturalGasUtilityAccumulatedDepreciation



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value7572748374177357722971267065704969276846683867066607648064426342624961416041595058425777
Percentage of ElectricAndNaturalGasUtilityAccumulatedDepreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:OtherAccumulatedDepreciation



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value408387375363348336325313300286274262251242285274264255247238232231
Percentage of OtherAccumulatedDepreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:PensionAndOtherPostretirementDefinedBenefitPlansAssetsNoncurrent

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value172166152146139132153147133126115109100950
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

es:PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value26184258502505924576241722389022971226352226822080210762076420495203381956119326189831882918185180581772817733
Percentage of PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value8970888086278452833482848002791478127786594458795869581255245521538953455139509550745062
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es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value300429692744
Percentage of PropertyPlantAndEquipmentNetExcludingConstructionWorkInProgress11.511.511.5

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value9288914289858881867485748243814779887889765175767433739371647073698769536762672465046504
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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value3984393137233632363535463371331732733244315830943049301028652819275927272657262525842595
Percentage of PublicUtilitiesPropertyPlantAndEquipmentDistributionNaturalGas100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicUtilitiesPropertyPlantAndEquipmentDistributionWater



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value17301726168616641649163915941571155615580
Percentage of PublicUtilitiesPropertyPlantAndEquipmentDistributionWater100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

es:PublicUtilitiesPropertyPlantAndEquipmentElectricAndNaturalGasUtilityTotal



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value33091326963191731415309523057529603292922879728520275092713926768264682565325359249222466823919236992325523192
Percentage of PublicUtilitiesPropertyPlantAndEquipmentElectricAndNaturalGasUtilityTotal100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:RateReductionBonds



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value5185405405615615835836040
Percentage of RateReductionBonds100.0100.0100.0100.0100.0100.0100.0100.00.0

dei:LegalEntity

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value518540583
Percentage of RateReductionBonds100.0100.0100.0

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Period End2020-03-312019-12-31
Value518540
Percentage of RateReductionBonds100.0100.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value596625634642623645631638
Percentage of RateReductionBonds114.9115.9117.4114.3111.0110.7108.2105.5

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Period End2020-03-312019-12-31
Value596625
Percentage of RateReductionBonds114.9115.9

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value561583583604604635635635
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Period End2020-03-312019-12-312018-12-31
Value561583635
Percentage of RateReductionBonds108.3108.0109.0

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value43434343435252300
Percentage of RateReductionBondsCurrent100.0100.0100.0100.0100.0100.0100.0100.00.0

dei:LegalEntity

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value434352
Percentage of RateReductionBondsCurrent100.0100.0100.0

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Period End2020-03-312019-12-312016-03-312015-12-31
Value192160170130
Percentage of RenewablePortfolioStandardsComplianceObligation100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value179150113661751391006513911169449475564413210467615535
Percentage of RenewablePortfolioStandardsComplianceObligation92.993.90.00.00.00.00.00.00.00.00.00.00.00.00.00.077.980.40.00.00.00.0

dei:LegalEntity

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-03-312014-12-31
Value10710811095110109133101101888667605587616256706334
Percentage of AccountsPayableOtherCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value505657525656645452525251556661616075678173
Percentage of AccountsPayableOtherCurrent46.952.352.554.650.651.348.053.759.661.278.685.599.476.8100.098.5107.1107.20.0129.2211.4

dei:LegalEntity

us-gaap:AccountsPayableRelatedPartiesCurrent

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value9396847211589777813791818969164466638257112763
Percentage of AccountsPayableRelatedPartiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value323726
Percentage of AccountsPayableRelatedPartiesCurrent35.039.429.0

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value88977676942686889082805467886360596693586765
Percentage of AccountsPayableRelatedPartiesCurrent94.9101.590.6106.481.929.5112.2112.666.090.198.7644.269.496.298.2130.388.9172.0365.581.952.4103.3

dei:LegalEntity

us-gaap:AccountsReceivableRelatedPartiesCurrent

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value66293925203143202640132848812241750840
Percentage of AccountsReceivableRelatedPartiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value1068
Percentage of AccountsReceivableRelatedPartiesCurrent15.222.626.9

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value3324343330233234292829221716249212128222716
Percentage of AccountsReceivableRelatedPartiesCurrent50.482.288.1133.7151.173.673.3169.3110.669.2214.879.7376.4196.4270.179.3714.9525.9164.145.4329.941.5

us-gaap:AccrualForEnvironmentalLossContingencies



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value79817071646466646354575758655959515146464343343435353638403938313126283026
Percentage of AccrualForEnvironmentalLossContingencies100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value689101010106222213222222111
Percentage of AccrualForEnvironmentalLossContingencies7.89.913.514.716.216.816.410.04.44.93.53.81.74.93.93.94.44.74.75.03.92.53.4

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-312017-12-31
Value7755
Percentage of AccrualForEnvironmentalLossContingencies9.49.38.310.4

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value1111655554544554444444533
Percentage of AccrualForEnvironmentalLossContingencies14.914.18.58.18.68.37.57.68.08.68.58.89.17.47.97.78.99.010.210.611.58.89.6

us-gaap:EnvironmentalRemediationSite

es:MgpSiteAccrual



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value67675657505052555749515153595353464541403538
Percentage of AccrualForEnvironmentalLossContingencies85.283.880.279.778.177.478.585.190.689.389.989.691.189.790.390.389.289.087.486.681.289.6

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value747970876675665962426241623462296224623962356232623062506256625262436262626062536241623562196201618561926185617661736183618318011797179217851777
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value181318131663165316531633160816031595150210471047104510451020995995995995995995994
Percentage of AdditionalPaidInCapital24.225.624.924.826.526.225.825.725.624.116.816.816.816.716.315.915.915.915.915.915.915.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value903903678
Percentage of AdditionalPaidInCapital12.112.710.9

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value2535253524102410241024102210221021192110211021102110211020562056205619101910180518051804
Percentage of AdditionalPaidInCapital33.935.836.136.238.638.635.535.534.133.833.833.933.933.832.932.932.930.530.528.928.928.9

us-gaap:AllowanceForDoubtfulAccountsReceivable



Period End2020-03-312019-12-312018-03-312017-03-31
Value2622241915
Percentage of AllowanceForDoubtfulAccountsReceivable100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany



Period End2020-03-312019-12-312018-03-312017-03-31
Value717576
Percentage of AllowanceForDoubtfulAccountsReceivable27.133.538.340.9

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-31
Value1110
Percentage of AllowanceForDoubtfulAccountsReceivable4.34.7

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312018-03-312017-03-31
Value1309732
Percentage of AllowanceForDoubtfulAccountsReceivable49.943.319.917.6

es:CumulativeEffectPeriodOfAdoption, dei:LegalEntity

es:CumulativeEffectPeriodOfAdoptionAdjustment, es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-01-01
Value300000.0
Percentage of AllowanceForDoubtfulAccountsReceivable0.0

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Period End2020-01-01
Value1
Percentage of AllowanceForDoubtfulAccountsReceivable0.0

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Period End2020-01-01
Value200000.0
Percentage of AllowanceForDoubtfulAccountsReceivable0.0

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Period End2020-01-01
Value900000.0
Percentage of AllowanceForDoubtfulAccountsReceivable0.0

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType

es:HardshipAccounts



Period End2020-03-312019-12-31
Value172143
Percentage of AllowanceForDoubtfulAccountsReceivable65.763.7

es:RetailNonHardshipWholesaleandOtherReceivables



Period End2020-03-312019-12-31
Value8981
Percentage of AllowanceForDoubtfulAccountsReceivable34.336.3

us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, dei:LegalEntity

es:HardshipAccounts, es:NstarElectricCompany



Period End2020-03-312019-12-31
Value3843
Percentage of AllowanceForDoubtfulAccountsReceivable14.719.5

es:HardshipAccounts, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-31
Value11080
Percentage of AllowanceForDoubtfulAccountsReceivable42.235.6

es:RetailNonHardshipWholesaleandOtherReceivables, es:NstarElectricCompany



Period End2020-03-312019-12-31
Value3231
Percentage of AllowanceForDoubtfulAccountsReceivable12.414.0

es:RetailNonHardshipWholesaleandOtherReceivables, es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-31
Value2017
Percentage of AllowanceForDoubtfulAccountsReceivable7.77.7

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value262224225226223212218211207195196199203200208205197190185209187175181197180171182186178165913434343839
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

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Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value71758081747482777269555452545956515246464340
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent27.133.535.836.133.535.037.636.535.035.628.327.425.927.328.827.726.127.625.022.123.423.2

es:PublicServiceCompanyOfNewHampshirePSNH



Period End2020-03-312019-12-312018-12-31
Value111011
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent4.34.75.2

es:TheConnecticutLightAndPowerCompany



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value1309794889388848082787777888685828479791008684
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent49.943.341.739.241.641.438.838.139.940.339.438.943.743.141.040.243.041.742.847.946.248.1

us-gaap:AmountOfRegulatoryCostsNotYetApproved



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-312011-09-302011-06-302010-12-31
Value17114614414212912210412412310510810391868783767559604960646511437
Percentage of AmountOfRegulatoryCostsNotYetApproved100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:LegalEntity

es:NstarElectricCompany