Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Revenues [Abstract]
Regulated electric		$ 21,379	$ 21,550	$ 20,329
Nonregulated electric, natural gas, and other		1,544	1,802	1,916
Regulated natural gas		536	573	511
Total operating revenues		23,459	23,925	22,756
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		7,308	7,686	7,108
Fuel used in electric generation and purchased power - nonregulated		354	533	540
Cost of natural gas		195	248	224
Operation, maintenance and other		5,871	5,856	5,673
Depreciation and amortization		3,144	3,066	2,668
Property and other taxes		1,135	1,213	1,274
Impairment charges		120	81	399
Total operating expenses		18,127	18,683	17,886
Gains (Losses) on Sales of Other Assets and Other, net		35	16	(16)
Operating Income (Loss)		5,367	5,258	4,854
Other Income and Expenses [Abstract]
Equity in earnings of unconsolidated affiliates		69	130	122
Gains on sales of unconsolidated affiliates		7	17	100
Other income and expenses, net		307	351	262
Total other income and expenses		383	498	484
Interest Expense		1,613	1,622	1,543
Income (Loss) From Continuing Operations Before Income Taxes		4,137	4,134	3,795
Income Tax Expense (Benefit) from Continuing Operations		1,326	1,669	1,205
Income (Loss) from Continuing Operations		2,811	2,465	2,590
(Loss) Income From Discontinued Operations, net of tax		20	(576)	86
Less: Net Income (Loss) Attributable to Noncontrolling Interests		15	6	11
Net Income (Loss) Attributable to Parent		2,816	1,883	2,665
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments	[1]	(13)	4	38
Net unrealized gain (loss) on cash flow hedges	[2]		(26)	59
Reclassification into earnings from cash flow hedges		9	7	1
Unrealized gain (loss) on investments in available for sale securities		(6)	3	(4)
Other comprehensive income (loss), net of tax		(274)	(136)	(99)
Comprehensive Income (Loss)		2,557	1,753	2,577
Less: Comprehensive Income Attributable to Noncontrolling Interests		4	14	5
Comprehensive income (loss)		$ 2,553	$ 1,739	$ 2,572
Income From Continuing Operations Attributable To Parent Common Shareholders [Abstract]
Basic		$ 4.02	$ 3.46	$ 3.64
Diluted		4.02	3.46	3.63
Income (loss) from discontinued operations attributable To Duke Energy Corporation common shareholders [Abstract]
Basic		0.03	(0.80)	0.13
Diluted		0.03	(0.80)	0.13
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic		4.05	2.66	3.77
Diluted		$ 4.05	$ 2.66	$ 3.76
Weighted-average shares outstanding [Abstract]
Basic		694	707	706
Diluted		694	707	706
Duke Energy Carolinas [Member]
Operating Revenues [Abstract]
Total operating revenues		$ 7,229	$ 7,351	$ 6,954
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		1,881	2,133	1,982
Operation, maintenance and other		2,066	1,995	1,868
Depreciation and amortization		1,051	1,009	921
Property and other taxes		269	316	374
Impairment charges		1	3
Total operating expenses		5,268	5,456	5,145
Gains (Losses) on Sales of Other Assets and Other, net		(1)
Operating Income (Loss)		1,960	1,895	1,809
Other Income and Expenses [Abstract]
Other income and expenses, net		160	172	120
Interest Expense		412	407	359
Income (Loss) From Continuing Operations Before Income Taxes		1,708	1,660	1,570
Income Tax Expense (Benefit) from Continuing Operations		627	588	594
Net Income (Loss) Attributable to Parent		1,081	1,072	976
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges		1	2	1
Unrealized gain (loss) on investments in available for sale securities		1
Other comprehensive income (loss), net of tax		2	2	1
Comprehensive income (loss)		1,083	1,074	977
Progress Energy [Member]
Operating Revenues [Abstract]
Total operating revenues		10,277	10,166	9,533
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		4,224	4,195	3,851
Operation, maintenance and other		2,298	2,335	2,247
Depreciation and amortization		1,116	1,128	883
Property and other taxes		492	517	557
Impairment charges		12	(16)	380
Total operating expenses		8,142	8,159	7,918
Gains (Losses) on Sales of Other Assets and Other, net		25	11	3
Operating Income (Loss)		2,160	2,018	1,618
Other Income and Expenses [Abstract]
Other income and expenses, net		97	77	94
Interest Expense		670	675	680
Income (Loss) From Continuing Operations Before Income Taxes		1,587	1,420	1,032
Income Tax Expense (Benefit) from Continuing Operations		522	540	373
Income (Loss) from Continuing Operations		1,065	880	659
(Loss) Income From Discontinued Operations, net of tax		(3)	(6)	16
Less: Net Income (Loss) Attributable to Noncontrolling Interests		11	5	3
Net Income (Loss) Attributable to Parent		1,051	869	672
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments		(10)	9	9
Reclassification into earnings from cash flow hedges		4	8	(1)
Unrealized gain (loss) on investments in available for sale securities		(1)	1
Other comprehensive income (loss), net of tax		(7)	18	8
Comprehensive Income (Loss)		1,055	892	683
Less: Comprehensive Income Attributable to Noncontrolling Interests		11	5	3
Comprehensive income (loss)		1,044	887	680
Duke Energy Progress [Member]
Operating Revenues [Abstract]
Total operating revenues		5,290	5,176	4,992
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		2,029	2,036	1,925
Operation, maintenance and other		1,452	1,470	1,357
Depreciation and amortization		643	582	534
Property and other taxes		140	174	223
Impairment charges		5	(18)	22
Total operating expenses		4,269	4,244	4,061
Gains (Losses) on Sales of Other Assets and Other, net		3	3	1
Operating Income (Loss)		1,024	935	932
Other Income and Expenses [Abstract]
Other income and expenses, net		71	51	57
Interest Expense		235	234	201
Income (Loss) From Continuing Operations Before Income Taxes		860	752	788
Income Tax Expense (Benefit) from Continuing Operations		294	285	288
Net Income (Loss) Attributable to Parent		566	467	500
Duke Energy Florida [Member]
Operating Revenues [Abstract]
Total operating revenues		4,977	4,975	4,527
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		2,195	2,158	1,927
Operation, maintenance and other		835	850	898
Depreciation and amortization		473	545	330
Property and other taxes		352	343	327
Impairment charges		7	2	358
Total operating expenses		3,862	3,898	3,840
Gains (Losses) on Sales of Other Assets and Other, net			1	1
Operating Income (Loss)		1,115	1,078	688
Other Income and Expenses [Abstract]
Other income and expenses, net		24	20	30
Interest Expense		198	201	180
Income (Loss) From Continuing Operations Before Income Taxes		941	897	538
Income Tax Expense (Benefit) from Continuing Operations		342	349	213
Net Income (Loss) Attributable to Parent		599	548	325
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized gain (loss) on cash flow hedges				(1)
Reclassification into earnings from cash flow hedges			1
Other comprehensive income (loss), net of tax			1	(1)
Comprehensive income (loss)		599	549	324
Duke Energy Ohio [Member]
Operating Revenues [Abstract]
Regulated electric		1,331	1,316	1,258
Nonregulated electric, natural gas, and other		33	19	34
Regulated natural gas		541	578	513
Total operating revenues		1,905	1,913	1,805
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		446	459	428
Fuel used in electric generation and purchased power - nonregulated		47	25	41
Cost of natural gas		141	185	152
Operation, maintenance and other		495	516	546
Depreciation and amortization		227	214	213
Property and other taxes		254	234	242
Impairment charges			94	5
Total operating expenses		1,610	1,727	1,627
Gains (Losses) on Sales of Other Assets and Other, net		8	1	4
Operating Income (Loss)		303	187	182
Other Income and Expenses [Abstract]
Other income and expenses, net		6	10	2
Interest Expense		79	86	74
Income (Loss) From Continuing Operations Before Income Taxes		230	111	110
Income Tax Expense (Benefit) from Continuing Operations		81	43	43
Income (Loss) from Continuing Operations		149	68	67
(Loss) Income From Discontinued Operations, net of tax		23	(563)	35
Net Income (Loss) Attributable to Parent		172	(495)	102
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments				1
Other comprehensive income (loss), net of tax				1
Comprehensive income (loss)		172	(495)	103
Duke Energy Indiana [Member]
Operating Revenues [Abstract]
Total operating revenues		2,890	3,175	2,926
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power - regulated		982	1,259	1,131
Operation, maintenance and other		682	670	649
Depreciation and amortization		434	413	342
Property and other taxes		61	128	71
Impairment charges		88
Total operating expenses		2,247	2,470	2,193
Gains (Losses) on Sales of Other Assets and Other, net		1
Operating Income (Loss)		644	705	733
Other Income and Expenses [Abstract]
Other income and expenses, net		11	22	18
Interest Expense		176	171	170
Income (Loss) From Continuing Operations Before Income Taxes		479	556	581
Income Tax Expense (Benefit) from Continuing Operations		163	197	223
Net Income (Loss) Attributable to Parent		316	359	358
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges		(2)		(2)
Other comprehensive income (loss), net of tax		(2)		(2)
Comprehensive income (loss)		$ 314	$ 359	$ 356

[1] Net of insignificant tax expense in 2015, 2014 and $17 million tax expense in 2013. See Note 21 for additional information.

[2] Net of insignificant tax expense in 2015, $13 million tax benefit in 2014 and $20 million tax expense in 2013.