Fair Value Of Financial Assets And Liabilities (Fair Value Measurement Amounts For Assets And Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments in available-for-sale auction rate securities, fair value	$ 29		$ 71
Nuclear decommissioning trust fund equity securities	2,837		1,337
Nuclear decommissioning trust fund debt securities	1,405		723
Other long-term trading and available-for-sale equity securities	72		68
Other trading and available-for sale debt securities	602		382
Derivative assets	103		74
Assets, Fair Value Disclosure, Total	5,048		2,655
Derivative liabilities	(756)		(264)
Net Assets Fair Value, Total	4,292		2,391
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments in available-for-sale auction rate securities, fair value	3	[1]	12
Nuclear decommissioning trust fund equity securities	1,592		1,337
Nuclear decommissioning trust fund debt securities	762		723
Derivative assets			1
Assets, Fair Value Disclosure, Total	2,357		2,073
Derivative liabilities	(12)	[2]
Net Assets Fair Value, Total	2,345
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	1,245		1,062
Nuclear decommissioning trust fund debt securities	643		585
Other trading and available-for sale debt securities	57		20
Derivative assets	11		5
Assets, Fair Value Disclosure, Total	1,956		1,672
Derivative liabilities	(440)		(799)
Net Assets Fair Value, Total	1,516		873
Progress Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	811		690
Nuclear decommissioning trust fund debt securities	448		398
Other trading and available-for sale debt securities	3		6
Derivative assets	2
Assets, Fair Value Disclosure, Total	1,264		1,094
Derivative liabilities	(166)		(248)
Net Assets Fair Value, Total	1,098		846
Progress Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	435		372
Nuclear decommissioning trust fund debt securities	194		187
Other trading and available-for sale debt securities	43		1
Derivative assets	9		5
Assets, Fair Value Disclosure, Total	681		565
Derivative liabilities	(270)		(499)
Net Assets Fair Value, Total	411		66
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	59		56
Assets, Fair Value Disclosure, Total	59		56
Derivative liabilities	(38)		(30)
Net Assets Fair Value, Total	21		26
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Equity Securities	49		46
Available-for-sale Securities, Debt Securities	29		28
Derivative assets	10		4
Assets, Fair Value Disclosure, Total	88		78
Derivative liabilities	(63)		(69)
Net Assets Fair Value, Total	25		9
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	2,762		1,285
Nuclear decommissioning trust fund debt securities	317		109
Other long-term trading and available-for-sale equity securities	63		61
Other trading and available-for sale debt securities	40		22
Derivative assets	18		43
Assets, Fair Value Disclosure, Total	3,200		1,520
Derivative liabilities	(17)		(36)
Net Assets Fair Value, Total	3,183		1,484
Level 1 [Member] | Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	1,523		1,285
Nuclear decommissioning trust fund debt securities	155		109
Assets, Fair Value Disclosure, Total	1,678		1,394
Net Assets Fair Value, Total	1,678
Level 1 [Member] | Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	1,239		1,061
Nuclear decommissioning trust fund debt securities	162		87
Other trading and available-for sale debt securities	17		20
Assets, Fair Value Disclosure, Total	1,418		1,168
Net Assets Fair Value, Total	1,418		1,168
Level 1 [Member] | Progress Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	811		690
Nuclear decommissioning trust fund debt securities	119		81
Other trading and available-for sale debt securities	3		6
Assets, Fair Value Disclosure, Total	933		777
Net Assets Fair Value, Total	933		777
Level 1 [Member] | Progress Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	429		371
Nuclear decommissioning trust fund debt securities	43		6
Other trading and available-for sale debt securities	3		1
Assets, Fair Value Disclosure, Total	475		378
Net Assets Fair Value, Total	475		378
Level 1 [Member] | Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	48		42
Assets, Fair Value Disclosure, Total	48		42
Derivative liabilities	(15)		(10)
Net Assets Fair Value, Total	33		32
Level 1 [Member] | Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Equity Securities	49		46
Assets, Fair Value Disclosure, Total	49		46
Derivative liabilities			(1)
Net Assets Fair Value, Total	49		45
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	54		46
Nuclear decommissioning trust fund debt securities	1,040		567
Other long-term trading and available-for-sale equity securities	9		7
Other trading and available-for sale debt securities	562		360
Derivative assets	22		6
Assets, Fair Value Disclosure, Total	1,687		986
Derivative liabilities	(591)		(164)
Net Assets Fair Value, Total	1,096		822
Level 2 [Member] | Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	48		46
Nuclear decommissioning trust fund debt securities	559		567
Derivative assets			1
Assets, Fair Value Disclosure, Total	607		614
Net Assets Fair Value, Total	607
Level 2 [Member] | Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	6		1
Nuclear decommissioning trust fund debt securities	481		498
Other trading and available-for sale debt securities	40
Derivative assets	11		5
Assets, Fair Value Disclosure, Total	538		504
Derivative liabilities	(402)		(775)
Net Assets Fair Value, Total	136		(271)
Level 2 [Member] | Progress Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund debt securities	329		317
Derivative assets	2
Assets, Fair Value Disclosure, Total	331		317
Derivative liabilities	(128)		(224)
Net Assets Fair Value, Total	203		93
Level 2 [Member] | Progress Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Nuclear decommissioning trust fund equity securities	6		1
Nuclear decommissioning trust fund debt securities	151		181
Other trading and available-for sale debt securities	40
Derivative assets	9		5
Assets, Fair Value Disclosure, Total	206		187
Derivative liabilities	(270)		(499)
Net Assets Fair Value, Total	(64)		(312)
Level 2 [Member] | Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2		5
Assets, Fair Value Disclosure, Total	2		5
Derivative liabilities	(8)		(8)
Net Assets Fair Value, Total	(6)		(3)
Level 2 [Member] | Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	29		28
Assets, Fair Value Disclosure, Total	29		28
Derivative liabilities	(63)		(68)
Net Assets Fair Value, Total	(34)		(40)
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments in available-for-sale auction rate securities, fair value	29		71
Nuclear decommissioning trust fund equity securities	21		6
Nuclear decommissioning trust fund debt securities	48		47
Derivative assets	63		25
Assets, Fair Value Disclosure, Total	161		149
Derivative liabilities	(148)		(64)
Net Assets Fair Value, Total	13		85
Level 3 [Member] | Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments in available-for-sale auction rate securities, fair value	3	[1]	12
Nuclear decommissioning trust fund equity securities	21		6
Nuclear decommissioning trust fund debt securities	48		47
Assets, Fair Value Disclosure, Total	72		65
Derivative liabilities	(12)	[2]
Net Assets Fair Value, Total	60
Level 3 [Member] | Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(38)		(24)
Net Assets Fair Value, Total	(38)		(24)
Level 3 [Member] | Progress Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(38)		(24)
Net Assets Fair Value, Total	(38)		(24)
Level 3 [Member] | Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	9		9
Assets, Fair Value Disclosure, Total	9		9
Derivative liabilities	(15)		(12)
Net Assets Fair Value, Total	(6)		(3)
Level 3 [Member] | Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	10		4
Assets, Fair Value Disclosure, Total	10		4
Net Assets Fair Value, Total	$ 10		$ 4

[1] Included in Other within Investments and Other Assets on the Consolidated Balance Sheets.

[2] Included in Other within Current Liabilities and Other within Deferred Credits and Other Liabilities on the Consolidated Balance Sheet.