Income Taxes (Components Of Income Tax Expense) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	$ (46)		$ (37)		$ (5)
Current state taxes	35		21		39
Current foreign taxes	133		164		125
Total current income taxes	122		148		159	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	513		526		639
Deferred state taxes	64		56		83
Deferred foreign taxes	20		32		20
Total deferred income taxes	597	[2]	614	[3]	742
Investment tax credit amortization	(14)		(10)		(11)
Total income tax expense included in Consolidated Statements of Operations	705		752		890
Total income tax benefit from discontinued operations	24				(1)
Total income tax expense included in Consolidated Statements of Operations	729		752		889
Uncertain tax benefits relating to temporary differences	27		43		(392)
Net operating loss carry forward	1,127		274
Parent Company [Member]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Total income tax expense included in Consolidated Statements of Operations	(96)		(64)		(118)
Duke Energy Carolinas [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	(1)		(122)		3
Current state taxes	(25)		30		(2)
Total current income taxes	(26)		(92)		1	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	408		531		388
Deferred state taxes	77		40		75
Total deferred income taxes	485	[2]	571	[3]	463
Investment tax credit amortization	(6)		(7)		(7)
Total income tax expense included in Consolidated Statements of Operations	453		472		457
Total income tax expense included in Consolidated Statements of Operations	453		472		457
Uncertain tax benefits relating to temporary differences	11		43		(300)
Net operating loss carry forward	245		79
Progress Energy [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	(88)		(91)		(46)
Current state taxes	2		29		(13)
Total current income taxes	(86)		(62)		(59)	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	226		365		505
Deferred state taxes	40		27		100
Total deferred income taxes	266	[2]	392	[3]	605	[4]
Investment tax credit amortization	(8)		(7)		(7)
Total income tax expense included in Consolidated Statements of Operations	172		323		539
Total income tax benefit from discontinued operations	29		(3)		(9)
Total income tax expense included in Consolidated Statements of Operations	201		320		530
Uncertain tax benefits relating to temporary differences	(42)		(3)		16
Net operating loss carry forward	357		213		37
Progress Energy Carolinas [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	(48)		(27)		73
Current state taxes	(6)		21		(8)
Total current income taxes	(54)		(6)		65	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	162		262		238
Deferred state taxes	9		6		53
Total deferred income taxes	171	[2]	268	[3]	291
Investment tax credit amortization	(7)		(6)		(6)
Total income tax expense included in Consolidated Statements of Operations	110		256		350
Total income tax expense included in Consolidated Statements of Operations	110		256		350
Uncertain tax benefits relating to temporary differences	(6)		(1)		15
Net operating loss carry forward	257		54
Progress Energy Florida [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	6		(60)		(44)
Current state taxes			5		(4)
Total current income taxes	6		(55)		(48)	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	121		214		286
Deferred state taxes	21		22		39
Total deferred income taxes	142	[2]	236	[3]	325	[4]
Investment tax credit amortization	(1)		(1)		(1)
Total income tax expense included in Consolidated Statements of Operations	147		180		276
Total income tax expense included in Consolidated Statements of Operations	147		180		276
Uncertain tax benefits relating to temporary differences	(36)		(19)		1
Net operating loss carry forward	25		41		9
Duke Energy Ohio [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	26		(95)		107
Current state taxes	11		1		8
Total current income taxes	37		(94)		115	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	72		194		6
Deferred state taxes	(9)		(2)		12
Total deferred income taxes	63	[2]	192	[3]	18
Investment tax credit amortization	(2)		(2)		(1)
Total income tax expense included in Consolidated Statements of Operations	98		96		132
Total income tax expense included in Consolidated Statements of Operations	98		96		132
Uncertain tax benefits relating to temporary differences	4		3		(3)
Net operating loss carry forward	99		47
Duke Energy Indiana [Member]
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current federal taxes	(27)		95		(3)
Current state taxes	27		42		16
Total current income taxes			137		13	[1]
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred federal taxes	(47)		(38)		123
Deferred state taxes	(25)		(23)		22
Total deferred income taxes	(72)	[2]	(61)	[3]	145
Investment tax credit amortization	(1)		(2)		(2)
Total income tax expense included in Consolidated Statements of Operations	(73)		74		156
Total income tax expense included in Consolidated Statements of Operations	(73)		74		156
Uncertain tax benefits relating to temporary differences	9		3		(7)
Net operating loss carry forward	$ 205

[1] Includes uncertain tax benefits relating primarily to certain temporary differences of $(392) million at Duke Energy, $(300) million at Duke Energy Carolinas, $16 million at Progress Energy, $15 million at Progress Energy Carolinas, $1 million at Progress Energy Florida, $(3) million at Duke Energy Ohio and $(7) million at Duke Energy Indiana. The offset to these temporary differences are included in deferred income taxes.

[2] Includes benefits of net operating loss (NOL) carryforwards of $1,127 million at Duke Energy, $245 million at Duke Energy Carolinas, $357 million at Progress Energy, $257 million at Progress Energy Carolinas, $25 million at Progress Energy Florida, $99 million at Duke Energy Ohio and $205 million at Duke Energy Indiana.

[3] Includes benefits of NOL carryforwards of $274 million at Duke Energy, $79 million at Duke Energy Carolinas, $213 million at Progress Energy, $54 million at Progress Energy Carolinas, $41 million at Progress Energy Florida and $47 million at Duke Energy Ohio.

[4] Includes benefits of NOL carryforwards of $37 million at Progress Energy and $9 million at Progress Energy Florida.