Business Segments (Business Segment Data) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	$ 6,395		$ 6,217		$ 18,366		$ 17,132
Segment income	888		942		2,356		1,890
Add back noncontrolling interests component	3		4		11		12
Income (Loss) From Discontinued Operations, net of tax	378		62		(578)		82
Net Income (Loss) Attributable to Parent	1,274		1,004		1,786		1,977
Net income (loss)	1,269		1,008		1,789		1,984
Segment assets	119,656				119,656				114,779
Impairment charges	1		2		81		388
Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	5,975		5,768	[1]	17,041		15,731	[1],[2],[3],[4]
Segment income	920		923	[1]	2,346		1,932	[1],[2],[3],[4],[5]
International Energy [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	366		370		1,111		1,168
Segment income	80		116		356		300
Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	50		56		195		184
Segment income	(17)		(28)		(70)	[6]	(54)
Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	4		23		19		49
Segment income	(92)	[7]	(64)	[7]	(269)	[7]	(278)	[7]
Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	6,391		6,194		18,347		17,083
Segment income	983		1,011		2,632		2,178
Operating Segments [Member] | Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	5,986		5,786		17,074		15,766
Segment assets	105,172				105,172
Operating Segments [Member] | International Energy [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	366		370		1,111		1,168
Segment assets	5,159				5,159
Operating Segments [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	50		58		195		189
Segment assets	6,196				6,196
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	6,402		6,214		18,380		17,123
Segment assets	116,527				116,527
Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(32)		(44)		(93)		(104)
Segment income	(3)		(5)		(7)		(10)
Segment assets	(185)				(185)
Intersegment Eliminations [Member] | Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(11)		(18)		(33)		(35)
Intersegment Eliminations [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues			(2)				(5)
Intersegment Eliminations [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(21)		(24)		(60)		(64)
Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(11)		(20)		(33)		(40)
Corporate, Non-Segment [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	25		47		79		113
Segment assets	2,944				2,944
Other VIEs [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Impairment charges					94
Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	446		438		1,433		1,349
Segment income	26		24		39		57
Income (Loss) From Discontinued Operations, net of tax	413		35		(597)		39
Net Income (Loss) Attributable to Parent	439		59		(558)		96
Segment assets	10,072				10,072				10,763
Impairment charges					94
Duke Energy Ohio [Member] | Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	440		421		1,416		1,317
Segment income	43		42		151		122
Duke Energy Ohio [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	6		17		17		32
Segment income	(13)		(13)		(101)	[8]	(51)
Duke Energy Ohio [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Segment income	(4)		(5)		(11)		(14)
Duke Energy Ohio [Member] | Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	446		438		1,433		1,349
Segment income	30		29		50		71
Duke Energy Ohio [Member] | Operating Segments [Member] | Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	441		421		1,417		1,317
Segment assets	7,297				7,297
Duke Energy Ohio [Member] | Operating Segments [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	6		17		17		32
Segment assets	3,266				3,266
Duke Energy Ohio [Member] | Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	447		438		1,434		1,349
Segment assets	10,563				10,563
Duke Energy Ohio [Member] | Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(1)				(1)
Segment assets	(622)				(622)
Duke Energy Ohio [Member] | Intersegment Eliminations [Member] | Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(1)				(1)
Duke Energy Ohio [Member] | Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	(1)				(1)
Duke Energy Ohio [Member] | Corporate, Non-Segment [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Segment assets	131				131
Duke Energy Ohio [Member] | Other VIEs [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Impairment charges					$ 94

[1] In September 2013, Duke Energy Carolinas implemented revised customer rates approved by the NCUC and the PSCSC. These rate increases impact Regulated Utilities.

[2] In June 2013, NCUC approved a Duke Energy Progress settlement agreement that included an increase in rates in the first year beginning in June 2013. This rate increase impacts Regulated Utilities.

[3] Regulated Utilities recorded an impairment charge related to Duke Energy Florida's Crystal River Unit 3. See Note 4 for additional information.

[4] In May 2013, the PUCO approved a Duke Energy Ohio settlement agreement that provides for a net annual increase in electric distribution revenues beginning in May 2013. This rate increase impacts Regulated Utilities.

[5] Regulated Utilities recorded an impairment charge related to the letter Duke Energy Progress filed with the NRC requesting the NRC to suspend its review activities associated with the combined construction and operating license (COL) at Harris site. Regulated Utilities also recorded an impairment charge related to the write-off of the wholesale portion of the Levy investments at Duke Energy Florida in accordance with the 2013 Settlement. See Note 4 for additional information.

[6] Commercial Power recorded a pretax impairment charge of $94 million related to reducing the carrying value of OVEC to zero. See Note 13 for additional information.

[7] Other includes costs to achieve the Progress Energy merger.

[8] Duke Energy Ohio recorded a pretax impairment charge of $94 million related to reducing the carrying value of OVEC to zero. See Note 13 for additional information.