Consolidated Statements Of Comprehensive Income (Parenthethical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension and OPEB related adjustments to AOCI, tax	$ 9	$ (23)	$ 150
Net unrealized gains (losses) on cash flow hedges, tax	6	(31)	1
Reclassification into earnings from cash flow hedges, tax	(1)	1	0
Unrealized gain on investments in available-for-sale securities, tax	4	4	8
Reclassification into earnings from available for sale securities, tax	(2)	(2)	0
Auction Rate Securities [Member]
Unrealized gain on investments in available-for-sale securities, tax	3	3	0
Duke Energy Carolinas [Member]
Reclassification into earnings from cash flow hedges, tax	1	2	2
Unrealized gain on investments in available-for-sale securities, tax	1		5
Progress Energy [Member]
Pension and OPEB related adjustments to AOCI, tax	1	(24)	8
Net unrealized gains (losses) on cash flow hedges, tax	(3)	(56)	(22)
Reclassification into earnings from pension and OPEB adjustments, tax	(1)	(3)	(2)
Reclassification into earnings from cash flow hedges, tax	6	5	4
Progress Energy Carolinas [Member]
Net unrealized gains (losses) on cash flow hedges, tax	(3)	(28)	(6)
Reclassification into earnings from cash flow hedges, tax	2	3	3
Progress Energy Florida [Member]
Net unrealized gains (losses) on cash flow hedges, tax	0	(15)	(4)
Reclassification into earnings from cash flow hedges, tax	1
Duke Energy Ohio [Member]
Pension and OPEB related adjustments to AOCI, tax	8	0	4
Reclassification into earnings from cash flow hedges, tax	0	0	(1)
Duke Energy Indiana [Member]
Reclassification into earnings from cash flow hedges, tax	$ (1)	$ (1)	$ (1)