Condensed Consolidated Statements Of Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Foreign Currency Adjustments [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]	Pension And OPEB Related Adjustments To AOCI [Member]	Common Stockholders' Equity [Member]	Noncontrolling Interest [Member]	Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member] Members Equity [Member]	Duke Energy Carolinas [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Duke Energy Carolinas [Member] Accumulated Net Unrealized Investment Gain (Loss) [Member]	Progress Energy [Member]	Progress Energy [Member] Common Stock [Member]	Progress Energy [Member] Additional Paid In Capital [Member]	Progress Energy [Member] Retained Earnings [Member]	Progress Energy [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Progress Energy [Member] Pension And OPEB Related Adjustments To AOCI [Member]	Progress Energy [Member] Common Stockholders' Equity [Member]		Progress Energy [Member] Noncontrolling Interest [Member]	Duke Energy Progress [Member]	Duke Energy Progress [Member] Common Stock [Member]	Duke Energy Progress [Member] Retained Earnings [Member]	Duke Energy Progress [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member] Common Stock [Member]	Duke Energy Florida [Member] Retained Earnings [Member]	Duke Energy Florida [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member] Common Stock [Member]	Duke Energy Ohio [Member] Additional Paid In Capital [Member]	Duke Energy Ohio [Member] Retained Earnings [Member]	Duke Energy Ohio [Member] Pension And OPEB Related Adjustments To AOCI [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member] Common Stock [Member]	Duke Energy Indiana [Member] Additional Paid In Capital [Member]	Duke Energy Indiana [Member] Retained Earnings [Member]	Duke Energy Indiana [Member] Net Gains (Losses) on Cash Flow Hedges [Member]
Balance at Dec. 31, 2011	$ 22,865	$ 1	$ 21,132	$ 1,873	$ (234)				$ 22,772	$ 93	$ 9,454	$ 9,473	$ (17)	$ (2)	$ 10,025	$ 7,418	$ 16	$ 2,752	$ (142)	$ (23)	$ 10,021		$ 4	$ 5,088	$ 2,148	$ 3,011	$ (71)	$ 4,675	$ 1,757	$ 2,945	$ (27)	$ 5,167	$ 762	$ 5,085	$ (652)	$ (28)	$ 3,734	$ 1	$ 1,358	$ 2,368	$ 7
Balance (in shares) at Dec. 31, 2011	445,000,000
Net income	299			295					295	4	266	266			152									52		52		128		128		74			74		(167)			(167)
Net income															150			150			150	[1]	0
Other comprehensive income (loss), net of tax	60				60	44	12	4	60						5				4	1	5			5			5	1			1	1				1	(1)				(1)
Common stock issuances, including dividend reinvestment and employee benefits (in shares)	1,000,000
Common stock issuances, including dividend reinvestment and employee benefits	(11)		(11)						(11)						17	12	5				17
Stock-based compensation expense																								7	7			3	3
Common stock dividends	(335)			(335)					(335)						(184)			(184)			(184)
Dividends paid to parent																								(175)		(175)		(105)		(105)
Preferred stock dividends at stated rates																								(1)		(1)		(1)		(1)
Transfer of Vermillion Generating Station																																(28)		(28)			26		26
Distributions to noncontrolling interests															(2)								(2)
Tax dividend																								(3)		(3)		(1)		(1)
Notes To Reconciliation Of Total Equity [Details]
Net income attributable to preferred shareholders of subsidiaries excluded from reconciliation of total equity															2
Balance at Mar. 31, 2012	22,878	1	21,121	1,833	(174)				22,781	97	9,720	9,739	(17)	(2)	10,011	7,430	21	2,718	(138)	(22)	10,009		2	4,973	2,155	2,884	(66)	4,700	1,760	2,966	(26)	5,214	762	5,057	(578)	(27)	3,592	1	1,384	2,201	6
Balance (in shares) at Mar. 31, 2012	446,000,000
Balance at Dec. 31, 2012	40,941	1	39,279	1,889	(306)				40,863	78			(15)	(1)	10,185		7,465	2,783	(42)	(25)	10,181		4	5,127	2,159	2,968		4,799	1,762	3,037		5,166	762	4,882	(477)	(1)	3,708	1	1,384	2,318	5
Balance (in shares) at Dec. 31, 2012	704,000,000														100									160,000,000				100				89,663,086					59,913,701
Beginning Member's Equity at Dec. 31, 2012											9,872	9,888
Net income	634			634					634		244	244			154									110		110		110		110		(21)			(21)		90			90
Net income															154			153			153		1
Other comprehensive income (loss), net of tax	17				17	4	10	3	17						2				1	1	2			0								1				1
Common stock issuances, including dividend reinvestment and employee benefits (in shares)	2,000,000
Common stock issuances, including dividend reinvestment and employee benefits	(16)		(16)						(16)
Common stock dividends	(542)			(542)					(542)
Premium on the redemption of preferred stock of subsidiaries	(3)			(3)					(3)						(3)			(3)			(3)			(2)		(2)		(1)		(1)
Changes in noncontrolling interest in subsidiaries	(1)									(1)
Transfer of Vermillion Generating Station																																					0
Distributions to noncontrolling interests															(3)								(3)
Notes To Reconciliation Of Total Equity [Details]
Net income attributable to preferred shareholders of subsidiaries excluded from reconciliation of total equity															0
Balance at Mar. 31, 2013	41,030	1	39,263	1,978	(289)				40,953	77			(15)	(1)	10,335		7,465	2,933	(41)	(24)	10,333		2	5,235	2,159	3,076		4,908	1,762	3,146		5,146	762	4,882	(498)		3,798	1	1,384	2,408	5
Balance (in shares) at Mar. 31, 2013	706,000,000														100									160,000,000				100				89,663,086					59,913,701
Ending Member's Equity at Mar. 31, 2013											$ 10,116	$ 10,132

[1] For the three months ended March 31, 2012, consolidated net income of $152 million includes $2 million attributable to preferred shareholders of subsidiaries. Income attributable to preferred shareholders of subsidiaries is not a component of total equity and is excluded from the table above.