Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2014 GWh dth		Dec. 31, 2013 GWh dth
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	29,569	[1]	71,466	[1]
Natural gas (millions of decatherms)	659,000,000		636,000,000
Duke Energy Carolinas [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		[1]	1,205	[1]
Natural gas (millions of decatherms)
Progress Energy [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		[1]	925	[1]
Natural gas (millions of decatherms)	319,000,000		363,000,000
Duke Energy Progress [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		[1]	925	[1]
Natural gas (millions of decatherms)	117,000,000		141,000,000
Duke Energy Florida [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)		[1]		[1]
Natural gas (millions of decatherms)	202,000,000		222,000,000
Duke Energy Ohio [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	25,680	[1]	69,362	[1]
Natural gas (millions of decatherms)	340,000,000		274,000,000
Duke Energy Indiana [Member]
Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value [Abstract]
Electricity-energy (Gigawatt-hours)	607	[1]	203	[1]
Natural gas (millions of decatherms)

[1] Amounts at Duke Energy Ohio include intercompany positions that eliminate at Duke Energy.