Risk Management, Derivative Instruments And Hedging Activities (Underlying Notional Amounts For Derivative Instruments Accounted For At Fair Value) (Details)	12 Months Ended
	Dec. 31, 2012 dth GWh GWm gal		Dec. 31, 2011 dth T GWh
Derivative [Line Items]
Electricity-energy (Gigawatt-hours)	52,104		14,118
Emission allowances: NOX (in tons)			9,000
Natural gas (in decatherms)	528,000,000		40,000,000
Electricity Capacity (Gigawatt Months)	5
Oil (millions of gallons)	5,000,000
Duke Energy Carolinas [Member]
Derivative [Line Items]
Electricity-energy (Gigawatt-hours)	2,028
Progress Energy [Member]
Derivative [Line Items]
Electricity-energy (Gigawatt-hours)	1,850
Natural gas (in decatherms)	348,000,000		347,000,000
Electricity Capacity (Gigawatt Months)	5
Oil (millions of gallons)	5,000,000		10,000,000
Progress Energy Carolinas [Member]
Derivative [Line Items]
Electricity-energy (Gigawatt-hours)	1,850
Natural gas (in decatherms)	118,000,000		103,000,000
Electricity Capacity (Gigawatt Months)	5
Progress Energy Florida [Member]
Derivative [Line Items]
Natural gas (in decatherms)	230,000,000		244,000,000
Oil (millions of gallons)	5,000,000		10,000,000
Duke Energy Ohio [Member]
Derivative [Line Items]
Electricity-energy (Gigawatt-hours)	51,215	[1]	14,655	[1]
Emission allowances: NOX (in tons)			9,000
Natural gas (in decatherms)	180,000,000		2,000,000
Duke Energy Indiana [Member]
Derivative [Line Items]
Electricity-energy (Gigawatt-hours)	97		682
Natural gas (in decatherms)			1,000,000

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