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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
Dec. 31, 2014
Dec. 31, 2013
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) $ 351us-gaap_DerivativeFairValueOfDerivativeAsset $ 461us-gaap_DerivativeFairValueOfDerivativeAsset
Location and fair value amounts of derivatives (Liability) 909us-gaap_DerivativeFairValueOfDerivativeLiability 636us-gaap_DerivativeFairValueOfDerivativeLiability
Current Assets, Other [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 210us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember		 214us-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) 136us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember		 233us-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) 573us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember		 322us-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) 319us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember		 299us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
Designated As Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 10us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 27us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Location and fair value amounts of derivatives (Liability) 42us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 23us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
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) 10us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 27us-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) 13us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 18us-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) 29us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember		 4us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
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)   1us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 341us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 434us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 867us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 613us-gaap_DerivativeFairValueOfDerivativeLiability
/ 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) 2us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= 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] | 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) 7us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 4us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
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) 18us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 201us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability)   158us-gaap_DerivativeFairValueOfDerivativeLiability
/ 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) 15us-gaap_DerivativeFairValueOfDerivativeAsset
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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] | 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		 215us-gaap_DerivativeFairValueOfDerivativeAsset
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability)   131us-gaap_DerivativeFairValueOfDerivativeLiability
/ 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) 15us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= duk_InvestmentsAndOtherAssetsAssetsHeldForSaleMember
/ 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
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= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 13us-gaap_DerivativeFairValueOfDerivativeAsset
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 307us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 153us-gaap_DerivativeFairValueOfDerivativeLiability
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= us-gaap_OtherCurrentLiabilitiesMember
/ 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) 174us-gaap_DerivativeFairValueOfDerivativeAsset
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= duk_CurrentLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		  
Location and fair value amounts of derivatives (Liability) 253us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= 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
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= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 5us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
Location and fair value amounts of derivatives (Liability) 91us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		 166us-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) 111us-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) 208us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= duk_DeferredCreditsAndOtherLiabilitiesAssetsHeldForSaleMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember		  
Duke Energy Carolinas [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 19us-gaap_DerivativeFairValueOfDerivativeLiability
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 2us-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) 14us-gaap_DerivativeFairValueOfDerivativeLiability
/ 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) 5us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		  
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 19us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 2us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ 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) 14us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 1us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ 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) 5us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
= duk_DukeEnergyCarolinasMember		 1us-gaap_DerivativeFairValueOfDerivativeLiability
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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) 2us-gaap_DerivativeFairValueOfDerivativeAsset
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 20us-gaap_DerivativeFairValueOfDerivativeAsset
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Location and fair value amounts of derivatives (Liability) 371us-gaap_DerivativeFairValueOfDerivativeLiability
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 204us-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) 2us-gaap_DerivativeFairValueOfDerivativeAsset
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= us-gaap_OtherCurrentAssetsMember
/ dei_LegalEntityAxis
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/ 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)   5us-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		 107us-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) 82us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember		 93us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | Designated As Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Liability) 1us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_HedgingDesignationAxis
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/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | 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) 1us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ dei_LegalEntityAxis
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/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | 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)   4us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ dei_LegalEntityAxis
= duk_ProgressEnergyMember
Progress Energy [Member] | Not Designated as Hedging Instrument [Member]    
Derivatives, Fair Value [Line Items]    
Location and fair value amounts of derivatives (Asset) 2us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ dei_LegalEntityAxis
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/ us-gaap_HedgingDesignationAxis
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