Fair Value Of Financial Assets and Liabilities (Reconciliation of Assets and Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended							3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Available For Sale Auction Rate Securities [Member]	Sep. 30, 2013 Available For Sale Auction Rate Securities [Member]	Sep. 30, 2012 Available For Sale Auction Rate Securities [Member]	Jun. 30, 2012 Available For Sale Auction Rate Securities [Member]	Sep. 30, 2013 Available For Sale Ndtf Investments [Member]	Sep. 30, 2012 Available For Sale Ndtf Investments [Member]	Sep. 30, 2013 Available For Sale Ndtf Investments [Member]	Sep. 30, 2012 Available For Sale Ndtf Investments [Member]	Sep. 30, 2013 Derivative [Member]	Sep. 30, 2012 Derivative [Member]	Sep. 30, 2013 Derivative [Member]	Sep. 30, 2012 Derivative [Member]	Sep. 30, 2013 Duke Energy Carolinas [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member]	Sep. 30, 2013 Duke Energy Carolinas [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member] Available For Sale Auction Rate Securities [Member]	Sep. 30, 2013 Duke Energy Carolinas [Member] Available For Sale Auction Rate Securities [Member]	Jun. 30, 2013 Duke Energy Carolinas [Member] Available For Sale Auction Rate Securities [Member]	Dec. 31, 2012 Duke Energy Carolinas [Member] Available For Sale Auction Rate Securities [Member]	Jun. 30, 2012 Duke Energy Carolinas [Member] Available For Sale Auction Rate Securities [Member]	Sep. 30, 2013 Duke Energy Carolinas [Member] Available For Sale Ndtf Investments [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member] Available For Sale Ndtf Investments [Member]	Sep. 30, 2013 Duke Energy Carolinas [Member] Available For Sale Ndtf Investments [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member] Available For Sale Ndtf Investments [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Carolinas [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Carolinas [Member] Derivative [Member]	Jun. 30, 2013 Duke Energy Carolinas [Member] Derivative [Member]	Sep. 30, 2013 Progress Energy [Member] Derivative [Member]	Sep. 30, 2012 Progress Energy [Member] Derivative [Member]	Sep. 30, 2013 Progress Energy [Member] Derivative [Member]	Sep. 30, 2012 Progress Energy [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Progress [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Progress [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Progress [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Progress [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Ohio [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Ohio [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Ohio [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Ohio [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Indiana [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Indiana [Member] Derivative [Member]	Sep. 30, 2013 Duke Energy Indiana [Member] Derivative [Member]	Sep. 30, 2012 Duke Energy Indiana [Member] Derivative [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 10	$ 86	$ 13	$ 85	$ 26	$ 29	$ 71	$ 41	$ 71	$ 64	$ 69	$ 53	$ (87)	$ (19)	$ (85)	$ (39)	$ 70	$ 70	$ 60	$ 65	$ 12	$ 3	$ 3	$ 3	$ 6	$ 71	$ 64	$ 69	$ 53		$ (12)		$ (4)	$ (35)	$ (30)	$ (38)	$ (24)	$ (35)	$ (28)	$ (38)	$ (24)	$ (19)	$ (2)	$ (6)	$ (3)	$ 18	$ 22	$ 10	$ 4
Amounts acquired in Progress Energy merger		(30)		(30)										(30)		(30)
Revenue, regulated electric	4	12	5	37									4	12	5	37																			2		2		2		2		1		1	3	11	5	35
Revenue, non-regulated electric, natural gas	9	(6)	(13)	(9)									9	(6)	(13)	(9)																										11	(6)	(4)	(5)
Gains on available for sale securities and other	1		(1)	9	1	(1)	9													2	2
Purchases	2	1	26	32					2	1	5	10			21	22	2	1	5	10						2	1	5	10															1				20
Sales	(2)		(5)						(2)		(5)						(2)		(5)							(2)		(5)																					22
Issuances	4	(24)	9	(24)									4	(24)	9	(24)		(14)		(14)										(14)		(14)		2	(16)	10	(16)		(16)	9	(16)
Settlements	(5)	(10)	(8)	(73)	(2)	(3)	(39)						(3)	(10)	(5)	(34)		2	8	(6)	(8)									2	8	2			4		4	2	4		4	2	(1)		1	(10)	(16)	(23)	(45)
Total gains (losses) included on the Condensed Consolidated Balance Sheet as regulatory asset or liability	2	3	(1)	5					1	1	3	3	1	2	(4)	2	1	1	3	3						1	1	3	3					(1)	4	(6)	(2)	(1)	2	(5)	(2)			3	(2)	3		2	1
Transfers in and/or out of level 3	34		34										34		34																			34		34		34		34
Ending balance	59	32	59	32	25	25	41	41	72	66	72	66	(38)	(75)	(38)	(75)	71	60	71	60	6	3	3	3	6	72	66	72	66	(12)	(4)	(12)	(4)	0	(36)	0	(36)	0	(36)	0	(36)	(6)	(8)	(6)	(8)	14	17	14	17
Revenue, regulated electric	3		5										3		5				(4)												(4)					10		1		10
Revenue, non regulated electric and other - non-regulated	(2)		(26)	5									(2)		(26)	5																										(3)		(16)	1
Total	$ 1		$ (21)	$ 5									$ 1		$ (21)	$ 5			$ (4)												$ (4)					$ 10		$ 1		$ 10		$ (3)		$ (16)	$ 1