Goodwill, Intangible Assets And Impairments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended																		12 Months Ended			3 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Duke Energy Carolinas [Member]	Dec. 31, 2011 Duke Energy Carolinas [Member]	Dec. 31, 2010 Duke Energy Carolinas [Member]	Dec. 31, 2012 Progress Energy [Member]	Dec. 31, 2011 Progress Energy [Member]	Dec. 31, 2010 Progress Energy [Member]	Dec. 31, 2012 Progress Energy Carolinas [Member]	Dec. 31, 2011 Progress Energy Carolinas [Member]	Dec. 31, 2010 Progress Energy Carolinas [Member]	Dec. 31, 2012 Progress Energy Florida [Member]	Dec. 31, 2012 Duke Energy Ohio [Member]	Dec. 31, 2011 Duke Energy Ohio [Member]	Dec. 31, 2010 Duke Energy Ohio [Member]	Jun. 30, 2010 Duke Energy Ohio [Member]	Sep. 30, 2009 Duke Energy Ohio [Member]	Dec. 31, 2012 Duke Energy Indiana [Member]	Dec. 31, 2011 Duke Energy Indiana [Member]	Dec. 31, 2010 Duke Energy Indiana [Member]	Jun. 30, 2010 Commercial Power [Member]	Dec. 31, 2012 Commercial Power [Member]	Dec. 31, 2011 Commercial Power [Member]	Dec. 31, 2011 Commercial Power [Member] Duke Energy Ohio [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment charge			$ 175													$ 237						$ 500
Pre-tax impairment charges related to certain generating assets and emission allowances																						160
Pre-tax impairment charge	666	335	726	31	12	0	200	3	5	54	3	5	146	2	89	837			579	234	44				79
Goodwill, Gross	$ 17,236	$ 4,720					$ 3,655	$ 3,655						$ 2,325	$ 2,325							$ 500	$ 933	$ 940
Customer Switching Level																	55.00%	29.00%