Consolidated Statements Of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net income	$ 1,782		$ 1,714		$ 1,323
Other comprehensive income(loss), net of tax
Foreign currency translation adjustments	(75)		(149)		79
Pension and OPEB related adjustments	19	[1]	(49)	[1]	276	[1]
Net unrealized gain (loss) on cash flow hedges	(28)	[2]	(57)	[2]	1	[2]
Reclassification into earnings from cash flow hedges	(1)	[3]	4	[3]	3	[3]
Unrealized gain (loss) on investments in auction rate securities	9	[4]	8	[4]	14	[4]
Unrealized gain (loss) on investments in available for sale securities	5	[5]	4	[5]
Reclassification into earnings from available for sale securities	(5)	[6]	(4)	[6]
Other comprehensive income (loss), net of tax	(76)		(243)		373
Comprehensive income	1,706		1,471		1,696
Comprehensive Income attributable to noncontrolling interests	10		1		2
Comprehensive income attributable to Duke Energy Corporation	1,696		1,470		1,694
Duke Energy Carolinas [Member]
Net income	865		834		838
Other comprehensive income(loss), net of tax
Reclassification into earnings from cash flow hedges	2	[7]	3	[7]	4	[7]
Unrealized gain (loss) on investments in auction rate securities	1	[8]			7	[8]
Other comprehensive income (loss), net of tax	3		3		11
Comprehensive income attributable to Duke Energy Corporation	868		837		849
Progress Energy [Member]
Net income	407		582		863
Other comprehensive income(loss), net of tax
Pension and OPEB related adjustments	4	[9]	(34)	[9]	13	[9]
Net unrealized gain (loss) on cash flow hedges	(5)	[10]	(87)	[10]	(34)	[10]
Reclassification into earnings from cash flow hedges	8	[11]	8	[11]	6	[11]
Other comprehensive income (loss), net of tax	98		(40)		(38)
Comprehensive income	505		542		825
Comprehensive Income attributable to noncontrolling interests	7		7		7
Comprehensive income attributable to Duke Energy Corporation	498		535		818
Progress Energy Carolinas [Member]
Net income	272		516		602
Other comprehensive income(loss), net of tax
Net unrealized gain (loss) on cash flow hedges	(4)	[12]	(43)	[12]	(10)	[12]
Reclassification into earnings from cash flow hedges	4	[13]	5	[13]	4	[13]
Other comprehensive income (loss), net of tax	71		(38)		(6)
Comprehensive income	343		478		596
Comprehensive Income attributable to noncontrolling interests					(1)
Comprehensive income attributable to Duke Energy Corporation	343		478		597
Progress Energy Florida [Member]
Net income	266		314		453
Other comprehensive income(loss), net of tax
Net unrealized gain (loss) on cash flow hedges			(23)	[14]	(7)	[14]
Reclassification into earnings from cash flow hedges	1	[15]
Other comprehensive income (loss), net of tax	27		(23)		(7)
Comprehensive income attributable to Duke Energy Corporation	293		291		446
Duke Energy Ohio [Member]
Net income	175		194		(441)
Other comprehensive income(loss), net of tax
Pension and OPEB related adjustments	(27)	[16]	6	[16]	(8)	[16]
Reclassification into earnings from cash flow hedges	0	[17]	0	[17]	(1)	[17]
Other comprehensive income (loss), net of tax	27		(6)		7
Comprehensive income attributable to Duke Energy Corporation	202		188		(434)
Duke Energy Indiana [Member]
Net income	(50)		168		285
Other comprehensive income(loss), net of tax
Reclassification into earnings from cash flow hedges	(2)	[18]	(1)	[18]	(2)	[18]
Other comprehensive income (loss), net of tax	(2)		(1)		(2)
Comprehensive income attributable to Duke Energy Corporation	$ (52)		$ 167		$ 283

[1] Net of $9 million tax expense in 2012, $23 million tax benefit in 2011 and $150 million tax expense in 2010.

[2] Net of $6 million tax expense in 2012, $31 million tax benefit in 2011 and $1 million tax expense in 2010.

[3] Net of $1 million tax benefit in 2012, $1 million tax expense in 2011 and insignificant tax expense in 2010.

[4] Net of $4 million tax expense in 2012, $4 million tax expense in 2011 and $8 million tax expense in 2010.

[5] Net of $3 million tax expense in 2012 and $3 million tax expense in 2011.

[6] Net of $2 million tax benefit in 2012 and $2 million tax benefit in 2011.

[7] Net of $1 million tax expense in 2012, $2 million tax expense in 2011 and $2 million tax expense in 2010.

[8] Net of $1 million tax expense in 2012 and $5 million tax expense in 2010.

[9] Net of $1 million tax benefit in 2012, $24 million tax expense in 2011 and $8 million tax benefit in 2010.

[10] Net of $3 million tax benefit in 2012, $56 million tax benefit in 2011 and $22 million tax benefit in 2010.

[11] Net of $6 million tax expense in 2012, $5 million tax expense in 2011 and $4 million tax expense in 2010.

[12] Net of $3 million tax benefit in 2012, $28 million tax benefit in 2011 and $6 million tax benefit in 2010.

[13] Net of $2 million tax expense in 2012, $3 million tax expense in 2011 and $3 million tax expense in 2010.

[14] Net of $15 million tax benefit in 2011 and $4 million tax benefit in 2010.

[15] Net of $1 million tax expense in 2012.

[16] Net of $8 million tax expense in 2012, insignificant tax expense in 2011 and $4 million tax expense in 2010.

[17] Net of $1 million tax benefit in 2010.

[18] Net of tax benefit of $1 million in 2012, 2011 and 2010.