Business Segments (Business Segment Data) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	$ 6,112	$ 6,709	$ 5,879	$ 5,898	$ 5,695	$ 6,722	$ 3,577	$ 3,630	$ 24,598		$ 19,624		$ 14,529
Interest Expense									1,546		1,242		859
Depreciation and amortization									2,808		2,289		1,806
Equity in earnings (losses) of unconsolidated affiliates									122		148		160
Income Tax Expense or Benefit from Continuing Operations									1,261		705		752
Segment income									2,648	[1],[2],[3],[4],[5],[6],[7]	1,732	[4],[8]	1,705	[10],[9]
Add back Noncontrolling interest component									11		14		8
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									17		36		1
Net Income (Loss)	692	1,008	342	634	437	598	448	299	2,676		1,782		1,714
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									5,607		5,958		4,464
Segment assets	114,779				113,856				114,779		113,856		62,526
Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									24,598	[1],[2],[3]	19,624		14,529
Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									20,910		16,080		10,619
Interest Expense									986		806		568
Depreciation and amortization									2,323		1,827		1,383
Equity in earnings (losses) of unconsolidated affiliates									(1)		(5)		0
Income Tax Expense or Benefit from Continuing Operations									1,522		942		674
Segment income									2,504	[1],[2],[3],[4],[5],[6],[7]	1,744	[4],[8]	1,181	[10],[9]
Segments Notes To Tables [Abstract]
After-tax deferral of voluntary severance program expense											60
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									5,049		4,220		3,717
Segment assets	99,884				98,162				99,884		98,162		47,977
Regulated Utilities [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									20,871	[1],[2],[3]	16,042		10,586
Regulated Utilities [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									39		38		33
Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									2,145		2,078		2,491
Interest Expense									64		63		87
Depreciation and amortization									250		228		230
Equity in earnings (losses) of unconsolidated affiliates									7		14		6
Income Tax Expense or Benefit from Continuing Operations									(104)		(8)		(2)
Segment income									(3)	[1],[2],[3],[4],[5],[6],[7]	87	[4],[8]	134	[10],[9]
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									268		1,038		492
Segment assets	6,955				6,992				6,955		6,992		6,939
Commercial Power [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									2,106	[1],[2],[3]	2,020		2,480
Commercial Power [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									39		58		11
International Energy [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,546		1,549		1,467
Interest Expense									86		77		47
Depreciation and amortization									100		99		90
Equity in earnings (losses) of unconsolidated affiliates									110		134		145
Income Tax Expense or Benefit from Continuing Operations									166		149		196
Segment income									408	[1],[2],[3],[4],[5],[6],[7]	439	[4],[8]	466	[10],[9]
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									67		551		114
Segment assets	4,998				5,406				4,998		5,406		4,539
International Energy [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,546	[1],[2],[3]	1,549		1,467
Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									24,601		19,707		14,577
Interest Expense									1,136		946		702
Depreciation and amortization									2,673		2,154		1,703
Equity in earnings (losses) of unconsolidated affiliates									116		143		151
Income Tax Expense or Benefit from Continuing Operations									1,584		1,083		868
Segment income									2,909	[1],[2],[3],[4],[5],[6],[7]	2,270	[4],[8]	1,781	[10],[9]
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									5,384		5,809		4,323
Segment assets	111,837				110,560				111,837		110,560		59,455
Total Reportable Segments [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									24,523	[1],[2],[3]	19,611		14,533
Total Reportable Segments [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									78		96		44
Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									163		60		44
Interest Expense									417		296		157
Depreciation and amortization									135		135		103
Equity in earnings (losses) of unconsolidated affiliates									6		5		9
Income Tax Expense or Benefit from Continuing Operations									(323)		(378)		(116)
Segment income									(261)	[1],[2],[3],[4],[5],[6],[7]	(538)	[4],[8]	(76)	[10],[9]
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									223		149		141
Segment assets	2,754				3,126				2,754		3,126		2,961
Other [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									75	[1],[2],[3]	13		(4)
Other [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									88		47		48
Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									(166)		(143)		(92)
Interest Expense									(7)
Segment Reporting Information Assets [Abstract]
Segment assets	188				170				188		170		110
Intersegment Eliminations [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									(166)		(143)		(92)
Duke Energy Carolinas [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	1,715	1,919	1,591	1,729	1,609	1,939	1,616	1,501	6,954		6,665		6,493
Interest Expense									359		384		360
Depreciation and amortization									921		921		814
Income Tax Expense or Benefit from Continuing Operations									594		453		472
Net Income (Loss)	209	342	181	244	130	258	211	266	976		865		834
Segment Reporting Information Assets [Abstract]
Segment assets	31,273				30,642				31,273		30,642
Duke Energy Carolinas [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Segment income									(97)		(169)		(46)
Progress Energy [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	2,300	2,766	2,281	2,186	2,227	2,788	2,288	2,102	9,533		9,405		8,948
Interest Expense									680		740		725
Depreciation and amortization									883		747		701
Income Tax Expense or Benefit from Continuing Operations									373		172		323
Add back Noncontrolling interest component									3		7		7
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest									16		52		(5)
Net Income (Loss)	196	342	(17)	154	34	157	64	152	675		407		582
Segment Reporting Information Assets [Abstract]
Segment assets	37,969				37,405				37,969		37,405
Progress Energy [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Interest Expense									300		304		324
Segment income									(241)		(379)		(273)
Duke Energy Progress [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	1,211	1,430	1,135	1,216	1,128	1,398	1,090	1,090	4,992		4,706		4,547
Interest Expense									201		207		184
Depreciation and amortization									534		535		514
Income Tax Expense or Benefit from Continuing Operations									288		110		256
Net Income (Loss)	138	175	77	110	93	96	31	52	500		272		516
Segment Reporting Information Assets [Abstract]
Segment assets	18,909				18,068				18,909		18,068
Duke Energy Progress [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Segment income									(46)		(139)		(18)
Duke Energy Florida [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	1,085	1,332	1,142	968	1,095	1,388	1,196	1,010	4,527		4,689		4,392
Interest Expense									180		255		239
Depreciation and amortization									330		192		169
Income Tax Expense or Benefit from Continuing Operations									213		147		180
Net Income (Loss)	75	197	(57)	110	(45)	100	83	128	325		266		314
Segment Reporting Information Assets [Abstract]
Segment assets	14,757				15,180				14,757		15,180
Duke Energy Florida [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Segment income									(24)		(58)		(16)
Duke Energy Ohio [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	868	819	811	747	766	757	717	912	3,245		3,152		3,181
Interest Expense									78		89		104
Depreciation and amortization									354		338		335
Income Tax Expense or Benefit from Continuing Operations									75		98		96
Segment income									102		175		194	[11]
Net Income (Loss)	6	59	58	(21)	42	14	45	74	102		175		194
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									433		514		499
Segment assets	10,763				10,560				10,763		10,560		10,939
Duke Energy Ohio [Member] | PJM Interconnection, LLC
Segment Reporting Information Assets [Abstract]
Entity-wide revenue, major customer, percentage									37.00%		36.00%		24.00%
Duke Energy Ohio [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									3,245	[12]	3,152	[13]	3,181	[14]
Duke Energy Ohio [Member] | Regulated Utilities [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,765		1,746		1,474
Interest Expense									74		61		68
Depreciation and amortization									200		179		168
Income Tax Expense or Benefit from Continuing Operations									91		91		98
Segment income									151		159		133
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									375		427		375
Segment assets	6,649				6,434				6,649		6,434		6,293
Duke Energy Ohio [Member] | Regulated Utilities [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,765		1,745		1,474
Duke Energy Ohio [Member] | Regulated Utilities [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues											1
Duke Energy Ohio [Member] | Commercial Power [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,512		1,458		1,711
Interest Expense									4		28		36
Depreciation and amortization									154		159		167
Income Tax Expense or Benefit from Continuing Operations									(14)		25		6
Segment income									(20)		50		78	[11]
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									58		87		124
Segment assets	4,170				4,175				4,170		4,175		4,740
Duke Energy Ohio [Member] | Commercial Power [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									1,480	[12]	1,407	[13]	1,707	[14]
Duke Energy Ohio [Member] | Commercial Power [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									32		51		4
Duke Energy Ohio [Member] | Total Reportable Segments [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									3,277		3,204		3,185
Interest Expense									78		89		104
Depreciation and amortization									354		338		335
Income Tax Expense or Benefit from Continuing Operations									77		116		104
Segment income									131		209		211	[11]
Segment Reporting Information Assets [Abstract]
Capital investments, expenditures and acquisitions									433		514		499
Segment assets	10,819				10,609				10,819		10,609		11,033
Duke Energy Ohio [Member] | Total Reportable Segments [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									3,245	[12]	3,152	[13]	3,181	[14]
Duke Energy Ohio [Member] | Total Reportable Segments [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									32		52		4
Duke Energy Ohio [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Income Tax Expense or Benefit from Continuing Operations									(2)		(18)		(8)
Segment income									(29)		(34)		(17)
Segment Reporting Information Assets [Abstract]
Segment assets	99				117				99		117		259
Duke Energy Ohio [Member] | Intersegment Eliminations [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									(32)		(52)		(4)
Segment Reporting Information Assets [Abstract]
Segment assets	(155)				(166)				(155)		(166)		(353)
Duke Energy Ohio [Member] | Intersegment Eliminations [Member] | Unaffiliated [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									0
Duke Energy Ohio [Member] | Intersegment Eliminations [Member] | Intersegment [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues									(32)		(52)		(4)
Duke Energy Indiana [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues	747	755	700	724	626	718	685	688	2,926		2,717		2,622
Interest Expense									170		138		137
Depreciation and amortization									342		389		391
Income Tax Expense or Benefit from Continuing Operations									223		(73)		74
Net Income (Loss)	82	104	82	90	59	(19)	77	(167)	358		(50)		168
Segment Reporting Information Assets [Abstract]
Segment assets	10,548				10,008				10,548		10,008
Duke Energy Indiana [Member] | Other [Member]
Segment Reporting Information, Profit (Loss) [Abstract]
Segment income									$ (16)		$ (27)		$ (12)

[1] In May 2013, Duke Energy Ohio implemented revised customer rates approved by the PUCO. This increase impacts Regulated Utilities. See Note 4 for additional information about the revised customer rates.

[2] In June 2013, Duke Energy Progress implemented revised customer rates approved by the NCUC. This increase impacts Regulated Utilities. See Note 4 for additional information about the revised customer rates.

[3] In September 2013, Duke Energy Carolinas implemented revised rates approved by the NCUC and the PSCSC. This increase impacts Regulated Utilities. See Note 4 for additional information about the revised customer rates.

[4] Other includes after-tax costs to achieve the merger with Progress Energy. See Notes 2 and 25 for additional information about the merger and related costs.

[5] Regulated Utilities recorded charges related to Duke Energy Florida's Crystal River Unit 3. See Note 4 for additional information about the Crystal River Unit 3 charges.

[6] Regulated Utilities recorded an impairment charge related to Duke Energy Progress' Shearon Harris Nuclear Station (Harris) site. Regulated Utilities also recorded an impairment charge related to Duke Energy Florida's proposed nuclear plant in Levy County, Florida (Levy) site. See Note 4 for additional information about the Harris site and Levy site impairments.

[7] Other includes gain from the sale of Duke Energy's ownership interest in DukeNet. See Note 12 for additional information on the sale of DukeNet.

[8] Regulated Utilities recorded charges related to Duke Energy Indiana's IGCC project. See Note 4 for additional information about these charges. Regulated Utilities also recorded the reversal of expenses of $60 million related to a prior year Voluntary Opportunity Plan in accordance with Duke Energy Carolinas' 2011 rate case. See Note 19 for additional information about these expenses.

[9] Regulated Utilities recorded charges related to Duke Energy Indiana's IGCC project. See Note 4 for additional information about these charges.

[10] Commercial Power recorded charges to write-down the carrying value of certain emission allowances. See Note 11 for additional information about these charges.

[11] Commercial Power recorded charges during the year ended December 31, 2011, to write-down the carrying value of certain emission allowances. See Note 11 for additional information.

[12] Duke Energy Ohio earned approximately 37 percent of its consolidated operating revenues from PJM Interconnection, LLC (PJM) in 2013, all of which is included in the Commercial Power segment. These revenues relate to the sale of capacity and electricity from Commercial Power's nonregulated generation assets.

[13] Duke Energy Ohio earned approximately 36 percent of its consolidated operating revenues from PJM in 2012, all of which is included in the Commercial Power segment. These revenues relate to the sale of capacity and electricity from Commercial Power's nonregulated generation assets.

[14] Duke Energy Ohio earned approximately 24 percent of its consolidated operating revenues from PJM in 2011, all of which is included in the Commercial Power segment. These revenues relate to the sale of capacity and electricity from Commercial Power's nonregulated generation assets.