Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Operating Revenues
Regulated electric	$ 5,090	$ 5,138	$ 10,547	$ 10,688
Nonregulated electric and other	403	463	780	954
Regulated natural gas	96	107	327	329
Total operating revenues	5,589	5,708	11,654	11,971
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,721	1,808	3,662	3,808
Fuel used in electric generation and purchased power – nonregulated	118	126	222	262
Cost of natural gas and other	26	38	137	154
Operation, maintenance and other	1,422	1,396	2,848	2,845
Depreciation and amortization	790	762	1,567	1,517
Property and other taxes	279	311	543	661
Impairment charges		(16)		80
Total operating expenses	4,356	4,425	8,979	9,327
Gains on Sales of Other Assets and Other, net	13	6	27	7
Operating Income (Loss)	1,246	1,289	2,702	2,651
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	23	33	36	69
Other income and expenses, net	72	89	146	184
Total other income and expenses	95	122	182	253
Interest Expense	403	403	806	807
Income (Loss) From Continuing Operations Before Income Taxes	938	1,008	2,078	2,097
Income Tax Expense (Benefit) from Continuing Operations	334	282	698	621
Income (Loss) from Continuing Operations	604	726	1,380	1,476
(Loss) Income From Discontinued Operations, net of tax	(57)	(113)	34	(956)
Net income (loss)	547	613	1,414	520
Less: Net Income Attributable to Noncontrolling Interests	4	4	7	8
Net Income (Loss) Attributable to Parent	543	609	1,407	512
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	7	1	2
Reclassification into earnings from cash flow hedges	1	(9)	5	(9)
Unrealized losses on available-for-sale securities	(3)	2	(3)	2
Other Comprehensive Income (Loss), net of tax	23	22	(110)	45
Comprehensive Income (Loss)	570	635	1,304	565
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	3	4	2	9
Comprehensive Income Attributable to Parent	$ 567	$ 631	$ 1,302	$ 556
Income from continuing operations attributable to Duke Energy Corporation common shareholders
Basic (usd per share)	$ 0.87	$ 1.02	$ 1.96	$ 2.07
Diluted (usd per share)	0.87	1.02	1.96	2.07
(Loss) Income from discontinued operations attributable to Duke Energy Corporation common shareholders
Basic (usd per share)	(0.09)	(0.16)	0.05	(1.35)
Diluted (usd per share)	(0.09)	(0.16)	0.05	(1.35)
Net income attributable to Duke Energy Corporation common shareholders
Basic (usd per share)	0.78	0.86	2.01	0.72
Diluted (usd per share)	$ 0.78	$ 0.86	$ 2.01	$ 0.72
Weighted-average shares outstanding
Basic (shares)	692	707	700	707
Diluted (shares)	692	707	700	707
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 1,707	$ 1,755	$ 3,608	$ 3,755
Operating Expenses
Fuel used in electric generation and purchased power – regulated	427	503	1,005	1,161
Operation, maintenance and other	469	463	958	950
Depreciation and amortization	261	248	510	490
Property and other taxes	67	100	137	204
Impairment charges		3		3
Total operating expenses	1,224	1,317	2,610	2,808
Operating Income (Loss)	483	438	998	947
Other Income and Expenses
Other income and expenses, net	41	44	83	93
Interest Expense	106	102	208	203
Income (Loss) From Continuing Operations Before Income Taxes	418	380	873	837
Income Tax Expense (Benefit) from Continuing Operations	153	110	316	281
Net Income (Loss) Attributable to Parent	265	270	557	556
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges		1		2
Other Comprehensive Income (Loss), net of tax				2
Comprehensive Income Attributable to Parent	265	271	557	558
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,476	2,421	5,012	4,962
Operating Expenses
Fuel used in electric generation and purchased power – regulated	1,003	977	2,035	2,020
Operation, maintenance and other	568	555	1,133	1,150
Depreciation and amortization	283	281	570	557
Property and other taxes	124	137	235	288
Impairment charges		(17)		(17)
Total operating expenses	1,978	1,933	3,973	3,998
Gains on Sales of Other Assets and Other, net	6		14	1
Operating Income (Loss)	504	488	1,053	965
Other Income and Expenses
Other income and expenses, net	19	13	46	28
Interest Expense	166	167	334	336
Income (Loss) From Continuing Operations Before Income Taxes	357	334	765	657
Income Tax Expense (Benefit) from Continuing Operations	140	127	284	246
Income (Loss) from Continuing Operations	217	207	481	411
(Loss) Income From Discontinued Operations, net of tax		(5)	(1)	(6)
Net income (loss)	217	202	480	405
Less: Net Income Attributable to Noncontrolling Interests	2		5	1
Net Income (Loss) Attributable to Parent	215	202	475	404
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1		2	1
Reclassification into earnings from cash flow hedges	1	4	(1)	4
Unrealized losses on available-for-sale securities	(1)		(1)
Other Comprehensive Income (Loss), net of tax	1	4	0	5
Comprehensive Income (Loss)	218	206	480	410
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	2		5	1
Comprehensive Income Attributable to Parent	216	206	475	409
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,193	1,191	2,642	2,613
Operating Expenses
Fuel used in electric generation and purchased power – regulated	449	454	1,024	1,027
Operation, maintenance and other	362	347	737	728
Depreciation and amortization	163	142	315	286
Property and other taxes	35	54	67	121
Impairment charges		(18)		(18)
Total operating expenses	1,009	979	2,143	2,144
Gains on Sales of Other Assets and Other, net			1	1
Operating Income (Loss)	184	212	500	470
Other Income and Expenses
Other income and expenses, net	15	7	35	16
Interest Expense	56	58	116	115
Income (Loss) From Continuing Operations Before Income Taxes	143	161	419	371
Income Tax Expense (Benefit) from Continuing Operations	58	60	151	137
Net Income (Loss) Attributable to Parent	85	101	268	234
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,281	1,225	2,367	2,341
Operating Expenses
Fuel used in electric generation and purchased power – regulated	554	523	1,011	993
Operation, maintenance and other	202	204	390	414
Depreciation and amortization	122	139	256	271
Property and other taxes	88	83	168	167
Impairment charges				1
Total operating expenses	966	949	1,825	1,846
Operating Income (Loss)	315	276	542	495
Other Income and Expenses
Other income and expenses, net	4	6	10	11
Interest Expense	50	50	99	99
Income (Loss) From Continuing Operations Before Income Taxes	269	232	453	407
Income Tax Expense (Benefit) from Continuing Operations	104	90	175	157
Net Income (Loss) Attributable to Parent	165	142	278	250
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges				1
Other Comprehensive Income (Loss), net of tax				1
Comprehensive Income Attributable to Parent	165	142	278	251
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	299	307	638	646
Nonregulated electric and other	9	(2)	23	11
Regulated natural gas	97	107	330	330
Total operating revenues	405	412	991	987
Operating Expenses
Fuel used in electric generation and purchased power – regulated	107	107	222	231
Fuel used in electric generation and purchased power – nonregulated	12	6	26	19
Cost of natural gas and other	12	22	109	121
Operation, maintenance and other	118	117	246	244
Depreciation and amortization	58	56	115	113
Property and other taxes	57	44	127	112
Impairment charges				94
Total operating expenses	364	352	845	934
Gains on Sales of Other Assets and Other, net	2		8
Operating Income (Loss)	43	60	154	53
Other Income and Expenses
Other income and expenses, net	(5)	3	(2)	6
Interest Expense	18	20	38	40
Income (Loss) From Continuing Operations Before Income Taxes	20	43	114	19
Income Tax Expense (Benefit) from Continuing Operations	7	15	42	6
Income (Loss) from Continuing Operations	13	28	72	13
(Loss) Income From Discontinued Operations, net of tax	(65)	(135)	25	(1,010)
Net Income (Loss) Attributable to Parent	(52)	(107)	97	(997)
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	686	748	1,474	1,593
Operating Expenses
Fuel used in electric generation and purchased power – regulated	235	287	529	626
Operation, maintenance and other	180	159	361	325
Depreciation and amortization	107	103	211	205
Property and other taxes	19	21	18	44
Total operating expenses	541	570	1,119	1,200
Gains on Sales of Other Assets and Other, net	1		1
Operating Income (Loss)	146	178	356	393
Other Income and Expenses
Other income and expenses, net	4	4	9	11
Interest Expense	43	44	88	87
Income (Loss) From Continuing Operations Before Income Taxes	107	138	277	317
Income Tax Expense (Benefit) from Continuing Operations	39	51	101	117
Net Income (Loss) Attributable to Parent	68	87	176	200
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges			(1)
Other Comprehensive Income (Loss), net of tax			(1)
Comprehensive Income Attributable to Parent	$ 68	$ 87	$ 175	$ 200