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Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) $ 411us-gaap_DerivativeFairValueOfDerivativeAsset $ 351us-gaap_DerivativeFairValueOfDerivativeAsset
Location and fair value amounts of derivatives (Liability) 984us-gaap_DerivativeFairValueOfDerivativeLiability 909us-gaap_DerivativeFairValueOfDerivativeLiability
Current Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 261us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember		 210us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
Investments And Other Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 150us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember		 136us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 607us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember		 573us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 377us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember		 319us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
Commodity Contracts [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 402us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember		 339us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
Location and fair value amounts of derivatives (Liability) 920us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember		 859us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
Interest Rate Contracts [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 9us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember		 12us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Location and fair value amounts of derivatives (Liability) 64us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember		 50us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Investments And Other Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 3us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 10us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 14us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 13us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 38us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 29us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 4us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 18us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Assets Held For Sale [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 45us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 21us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= duk_CurrentAssetsAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		  
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset)   3us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Investments And Other Assets, Assets Held For Sale [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 21us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= duk_InvestmentsAndOtherAssetsAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 15us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 7us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		  
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 1us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 1us-gaap_DerivativeFairValueOfDerivativeAsset
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/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 308us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 307us-gaap_DerivativeFairValueOfDerivativeLiability
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Assets Held For Sale [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 206us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= duk_CurrentLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 174us-gaap_DerivativeFairValueOfDerivativeAsset
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Location and fair value amounts of derivatives (Liability) 263us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= duk_CurrentLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 253us-gaap_DerivativeFairValueOfDerivativeLiability
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= duk_CurrentLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 2us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 2us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
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Location and fair value amounts of derivatives (Liability) 112us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 91us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits and Other Liabilities Assets Held For Sale [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 123us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= duk_DeferredCreditsAndOtherLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 111us-gaap_DerivativeFairValueOfDerivativeAsset
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= duk_DeferredCreditsAndOtherLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 209us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 208us-gaap_DerivativeFairValueOfDerivativeLiability
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 5us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 2us-gaap_DerivativeFairValueOfDerivativeAsset
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= us-gaap_OtherCurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Investments And Other Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 1us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		  
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 1us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 1us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 11us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 7us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Duke Energy Carolinas [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 27us-gaap_DerivativeFairValueOfDerivativeLiability
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 19us-gaap_DerivativeFairValueOfDerivativeLiability
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 19us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ dei_LegalEntityAxis
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/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember
Duke Energy Carolinas [Member] | Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 8us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 5us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember
Duke Energy Carolinas [Member] | Commodity Contracts [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 27us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 19us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 14us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 8us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 5us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember
Progress Energy [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 9us-gaap_DerivativeFairValueOfDerivativeAsset
/ dei_LegalEntityAxis
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/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Location and fair value amounts of derivatives (Liability) 398us-gaap_DerivativeFairValueOfDerivativeLiability
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 371us-gaap_DerivativeFairValueOfDerivativeLiability
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | Current Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 6us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 2us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | Investments And Other Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 3us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		  
Progress Energy [Member] | Current Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 289us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 289us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | Deferred Credits And Other Liabilities, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 109us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 82us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | Commodity Contracts [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 3us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_DerivativeInstrumentRiskAxis
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