Income Taxes (Summary Of Interest And Penalties Recognized) (Details) (USD $) In Millions, unless otherwise specified							12 Months Ended			12 Months Ended			12 Months Ended			12 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, 2010 Progress Energy [Member]	Dec. 31, 2011 Progress Energy [Member]	Dec. 31, 2010 Progress Energy Carolinas [Member]	Dec. 31, 2012 Progress Energy Carolinas [Member]	Dec. 31, 2011 Progress Energy Carolinas [Member]	Dec. 31, 2012 Progress Energy Florida [Member]	Dec. 31, 2010 Progress Energy Florida [Member]	Dec. 31, 2011 Progress Energy Florida [Member]	Dec. 31, 2011 Duke Energy Ohio [Member]	Dec. 31, 2012 Duke Energy Ohio [Member]	Dec. 31, 2010 Duke Energy Ohio [Member]	Dec. 31, 2011 Duke Energy Indiana [Member]	Dec. 31, 2012 Duke Energy Indiana [Member]	Dec. 31, 2010 Duke Energy Indiana [Member]
Income Tax Examination [Line Items]
Net interest income recognized related to income taxes	$ 10	$ 12	$ 26	$ 9	$ 5	$ 18			$ 24			$ 6			$ 22			$ 4		$ 2	$ 5
Net interest expense recognized related to income taxes							2	9		4			2	5		1			1
Interest receivable related to income taxes		8		7	5
Interest payable related to income taxes	$ 7						$ 17		$ 21		$ 8	$ 8	$ 9		$ 7	$ 3	$ 3		$ 3	$ 1