Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Operating Revenues
Regulated electric	$ 6,017	$ 5,861	$ 16,564	$ 16,549
Nonregulated electric and other	377	449	1,157	1,403
Regulated natural gas	89	85	416	414
Total operating revenues	6,483	6,395	18,137	18,366
Operating Expenses
Fuel used in electric generation and purchased power – regulated	2,113	2,132	5,775	5,940
Fuel used in electric generation and purchased power – nonregulated	61	148	283	410
Cost of natural gas and other	21	27	158	181
Operation, maintenance and other	1,426	1,409	4,274	4,254
Depreciation and amortization	774	788	2,341	2,305
Property and other taxes	293	275	836	936
Impairment charges	111	1	111	81
Total operating expenses	4,799	4,780	13,778	14,107
Gains (Losses) on Sales of Other Assets and Other, net	4	4	31	11
Operating Income	1,688	1,619	4,390	4,270
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	17	28	53	97
Other income and expenses, net	57	109	203	293
Total other income and expenses	74	137	256	390
Interest Expense	402	405	1,208	1,212
Income From Continuing Operations Before Income Taxes	1,360	1,351	3,438	3,448
Income Tax Expense from Continuing Operations	420	460	1,118	1,081
Income from Continuing Operations	940	891	2,320	2,367
(Loss) Income From Discontinued Operations, net of tax	(5)	378	29	(578)
Net income	935	1,269	2,349	1,789
Less: Net Income (Loss) Attributable to Noncontrolling Interests	3	(5)	10	3
Net Income (Loss) Attributable to Parent	932	1,274	2,339	1,786
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	(3)	1	(1)	1
Reclassification into earnings from cash flow hedges	1	2	6	5
Unrealized gains (losses) on available-for-sale securities	(2)		(5)	2
Other Comprehensive Income, net of tax	(135)	(97)	(245)	(52)
Comprehensive Income	800	1,172	2,104	1,737
Less: Comprehensive Income Attributable to Noncontrolling Interests	(2)	(1)		8
Comprehensive Income Attributable to Parent	$ 802	$ 1,173	$ 2,104	$ 1,729
Income from continuing operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	$ 1.36	$ 1.25	$ 3.31	$ 3.33
Diluted (usd per share)	1.36	1.25	3.31	3.33
(Loss) Income from discontinued operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	(0.01)	0.55	0.05	(0.81)
Diluted (usd per share)	(0.01)	0.55	0.05	(0.81)
Net income attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	1.35	1.80	3.36	2.52
Diluted (usd per share)	$ 1.35	$ 1.80	$ 3.36	$ 2.52
Weighted-average shares outstanding
Basic (shares)	688	707	696	707
Diluted (shares)	688	707	696	707
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 2,061	$ 1,938	$ 5,669	$ 5,693
Operating Expenses
Fuel used in electric generation and purchased power – regulated	548	524	1,553	1,685
Operation, maintenance and other	511	465	1,469	1,415
Depreciation and amortization	269	260	779	750
Property and other taxes	67	59	204	263
Impairment charges				3
Total operating expenses	1,395	1,308	4,005	4,116
Operating Income	666	630	1,664	1,577
Other Income and Expenses
Other income and expenses, net	42	44	125	137
Interest Expense	105	104	313	307
Income From Continuing Operations Before Income Taxes	603	570	1,476	1,407
Income Tax Expense from Continuing Operations	220	193	536	474
Net Income (Loss) Attributable to Parent	383	377	940	933
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges	1		1	2
Unrealized gains (losses) on available-for-sale securities	1		1
Other Comprehensive Income, net of tax	2		2	2
Comprehensive Income Attributable to Parent	385	377	942	935
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,929	2,863	7,941	7,825
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,238	1,214	3,273	3,234
Operation, maintenance and other	539	564	1,672	1,714
Depreciation and amortization	261	294	831	851
Property and other taxes	132	127	367	415
Impairment charges	7	1	7	(16)
Total operating expenses	2,177	2,200	6,150	6,198
Gains (Losses) on Sales of Other Assets and Other, net	4	2	18	3
Operating Income	756	665	1,809	1,630
Other Income and Expenses
Other income and expenses, net	17	26	63	54
Interest Expense	170	166	504	502
Income From Continuing Operations Before Income Taxes	603	525	1,368	1,182
Income Tax Expense from Continuing Operations	151	195	435	441
Income from Continuing Operations	452	330	933	741
(Loss) Income From Discontinued Operations, net of tax	(1)		(2)	(6)
Net income	451	330	931	735
Less: Net Income (Loss) Attributable to Noncontrolling Interests	3	1	8	2
Net Income (Loss) Attributable to Parent	448	329	923	733
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	(3)	1	(1)	2
Reclassification into earnings from cash flow hedges	3	1	2	5
Unrealized gains (losses) on available-for-sale securities		1	(1)	1
Other Comprehensive Income, net of tax	0	3	0	8
Comprehensive Income	451	333	931	743
Less: Comprehensive Income Attributable to Noncontrolling Interests	3	1	8	2
Comprehensive Income Attributable to Parent	448	332	923	741
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,488	1,367	4,130	3,980
Operating Expenses
Fuel used in electric generation and purchased power – regulated	584	552	1,608	1,579
Operation, maintenance and other	329	346	1,066	1,074
Depreciation and amortization	147	155	462	441
Property and other taxes	35	29	102	150
Impairment charges				(18)
Total operating expenses	1,095	1,082	3,238	3,226
Gains (Losses) on Sales of Other Assets and Other, net	1		2	1
Operating Income	394	285	894	755
Other Income and Expenses
Other income and expenses, net	14	18	49	34
Interest Expense	59	57	175	172
Income From Continuing Operations Before Income Taxes	349	246	768	617
Income Tax Expense from Continuing Operations	120	89	271	226
Net Income (Loss) Attributable to Parent	229	157	497	391
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,436	1,491	3,803	3,832
Operating Expenses
Fuel used in electric generation and purchased power – regulated	654	662	1,665	1,655
Operation, maintenance and other	208	212	598	626
Depreciation and amortization	113	139	369	410
Property and other taxes	97	99	265	266
Impairment charges	7	1	7	2
Total operating expenses	1,079	1,113	2,904	2,959
Operating Income	357	378	899	873
Other Income and Expenses
Other income and expenses, net	2	6	12	17
Interest Expense	50	51	149	150
Income From Continuing Operations Before Income Taxes	309	333	762	740
Income Tax Expense from Continuing Operations	93	128	268	285
Net Income (Loss) Attributable to Parent	216	205	494	455
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges				1
Other Comprehensive Income, net of tax				1
Comprehensive Income Attributable to Parent	216	205	494	456
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	367	352	1,005	998
Nonregulated electric and other	6	6	29	17
Regulated natural gas	89	88	419	418
Total operating revenues	462	446	1,453	1,433
Operating Expenses
Fuel used in electric generation and purchased power – regulated	128	129	350	360
Fuel used in electric generation and purchased power – nonregulated	10	5	36	24
Cost of natural gas and other	7	8	116	129
Operation, maintenance and other	124	134	370	378
Depreciation and amortization	57	54	172	167
Property and other taxes	60	58	187	170
Impairment charges				94
Total operating expenses	386	388	1,231	1,322
Gains (Losses) on Sales of Other Assets and Other, net			8
Operating Income	76	58	230	111
Other Income and Expenses
Other income and expenses, net		3	(2)	9
Interest Expense	20	20	58	60
Income From Continuing Operations Before Income Taxes	56	41	170	60
Income Tax Expense from Continuing Operations	22	15	64	21
Income from Continuing Operations	34	26	106	39
(Loss) Income From Discontinued Operations, net of tax	(2)	413	23	(597)
Net Income (Loss) Attributable to Parent	32	439	129	(558)
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	749	790	2,223	2,383
Operating Expenses
Fuel used in electric generation and purchased power – regulated	250	319	779	945
Operation, maintenance and other	164	160	525	485
Depreciation and amortization	109	104	320	309
Property and other taxes	23	25	41	69
Impairment charges	85		85
Total operating expenses	631	608	1,750	1,808
Gains (Losses) on Sales of Other Assets and Other, net	(1)
Operating Income	117	182	473	575
Other Income and Expenses
Other income and expenses, net		5	9	16
Interest Expense	44	40	132	127
Income From Continuing Operations Before Income Taxes	73	147	350	464
Income Tax Expense from Continuing Operations	27	46	128	163
Net Income (Loss) Attributable to Parent	46	101	222	301
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges	(1)		(2)
Other Comprehensive Income, net of tax			(2)
Comprehensive Income Attributable to Parent	$ 45	$ 101	$ 220	$ 301