Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	$ 832	$ 1,587
Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	34	290
Interest Rate Contracts [Member] | Cash Flow Hedging [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	798	1,047
Interest Rate Contracts [Member] | Fair Value Hedging [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		250
Interest Rate Contracts [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Cash Flow Hedging [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	584	620
Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	71,466	52,104
Natural gas (millions of decatherms)	636	528
Duke Energy Carolinas [Member] | Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	1,205	2,028
Progress Energy [Member] | Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		50
Progress Energy [Member] | Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		50
Progress Energy [Member] | Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	925	1,850
Natural gas (millions of decatherms)	363	348
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		50
Duke Energy Progress [Member] | Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		50
Duke Energy Progress [Member] | Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	925	1,850
Natural gas (millions of decatherms)	141	118
Duke Energy Florida [Member] | Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Natural gas (millions of decatherms)	222	230
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	27	277
Duke Energy Ohio [Member] | Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount	27	27
Duke Energy Ohio [Member] | Interest Rate Contracts [Member] | Fair Value Hedging [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		250
Duke Energy Ohio [Member] | Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	69,362	51,215
Natural gas (millions of decatherms)	274	180
Duke Energy Indiana [Member] | Interest Rate Contracts [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		200
Duke Energy Indiana [Member] | Interest Rate Contracts [Member] | Nondesignated [Member]
Notional Amounts Of Derivative Instruments Related To Interest Rate Risk [Abstract]
Derivative, Notional Amount		200
Duke Energy Indiana [Member] | Commodity Contracts [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	$ 203	$ 97