Regulatory Matters (Schedule Of Net Carrying Value Of Facilities As Well As The Remaining Non-current Regulatory Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 MW	Dec. 31, 2011
Megawatt of potential plants to be retired	3,954
Remaining net book value of potential plants to be retired	$ 428
Generation facilities to be retired, net	136	80
Duke Energy Carolinas [Member]
Megawatt of potential plants to be retired	910
Remaining net book value of potential plants to be retired	106
Generation facilities to be retired, net	73	80
Retired MW	587
Committed to retire	1,667
Duke Energy Indiana [Member]
Megawatt of potential plants to be retired	668
Remaining net book value of potential plants to be retired	132
Duke Energy Ohio [Member]
Megawatt of potential plants to be retired	928
Remaining net book value of potential plants to be retired	12
Progress Energy Carolinas [Member]
Megawatt of potential plants to be retired	575
Remaining net book value of potential plants to be retired	63
Generation facilities to be retired, net	63	163
Progress Energy Florida [Member]
Megawatt of potential plants to be retired	873
Remaining net book value of potential plants to be retired	$ 115