Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net Income	$ 1,008		$ 598		$ 1,984		$ 1,345
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	(8)		2		(137)		(85)
Pension and OPEB related adjustments			(21)	[1]	5	[1]	(15)	[1]
Net unrealized gain (loss) on cash flow hedges	1	[2]	(2)	[2]	55	[2]	(19)	[2]
Reclassification into earnings from cash flow hedges	1		(2)		1
Unrealized gain (loss) on investments in auction rate securities			1				7
Unrealized gain (loss) on investments in available for sale securities	(1)		3		(5)		6
Reclassification into earnings from available for sale securities	3		(1)		3		(4)
Other Comprehensive Income (Loss), Net of Tax	(4)		(20)		(78)		(110)
Comprehensive Income	1,004		578		1,906		1,235
Less: Comprehensive Income Attributable to Noncontrolling Interests	4		4		3		8
Comprehensive Income Attributable to Duke Energy Corporation	$ 1,000		$ 574		$ 1,903		$ 1,227

[1] Net of insignificant tax expense and $2 million tax expense for the three and nine months ended September 30, 2013 and $10 million tax benefit and $7 million tax benefit for the three and nine months ended September 30, 2012.

[2] Net of $1 million tax benefit and $17 million tax expense for the three and nine months ended September 30, 2013 and $1 million tax benefit and $10 million tax benefit for the three and nine months ended September 30, 2012.