Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Net Income	$ 342		$ 448		$ 976		$ 747
Other Comprehensive Income(Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	(133)		(131)		(129)		(87)
Pension and OPEB related adjustments	2		2		5		6
Net unrealized gain (loss) on cash flow hedges	44	[1]	(30)	[1]	54	[1]	(17)	[1]
Reclassification into earnings from cash flow hedges			3				2
Unrealized gain (loss) on investments in auction rate securities			6				6
Unrealized gain (loss) on investments in available for sale securities	(4)		2		(4)		3
Reclassification into earnings from available for sale securities	0		(2)		0		(3)
Other Comprehensive Income (Loss), Net of Tax	(91)		(150)		(74)		(90)
Comprehensive Income	251		298		902		657
Less: Comprehensive Income Attributable to Noncontrolling Interests	(1)		0		(1)		4
Comprehensive Income Attributable to Duke Energy Corporation	$ 252		$ 298		$ 903		$ 653

[1] Net of $14 million tax expense and $18 million tax expense for the three and six months ended June 30, 2013 and $14 million tax benefit and $9 million tax benefit for the three and six months ended June 30, 2012.