Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating Revenues
Regulated electric	$ 6,216	$ 6,091	$ 16,678	$ 16,122
Regulated natural gas	230	247	1,221	1,168
Nonregulated electric and other	182	144	507	476
Total operating revenues	6,628	6,482	18,406	17,766
Operating Expenses
Operation, maintenance and other	1,584	1,476	4,592	4,385
Depreciation and amortization	1,039	900	2,979	2,594
Property and other taxes	323	313	954	924
Impairment charges	124	207	339	216
Total operating expenses	5,059	4,827	14,505	13,374
Gains (Losses) on Sales of Other Assets and Other, net	10	6	(87)	24
Operating Income	1,579	1,661	3,814	4,416
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	37	36	49	101
Other income and expenses, net	131	122	327	358
Total other income and expenses	168	158	376	459
Interest Expense	517	498	1,550	1,475
Income From Continuing Operations Before Income Taxes	1,230	1,321	2,640	3,400
Income Tax Expense From Continuing Operations	168	364	449	1,035
Income From Continuing Operations	1,062	957	2,191	2,365
Income (Loss) From Discontinued Operations, net of tax	4	(2)	(1)	(4)
Net Income	1,066	955	2,190	2,361
Less: Net (Loss) Income Attributable to Noncontrolling Interests	(16)	1	(12)	5
Net Income Attributable to Duke Energy Corporation	1,082	954	2,202	2,356
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1		3	2
Net unrealized (losses) gains on cash flow hedges	(3)	2	10	(2)
Reclassification into earnings from cash flow hedges	6	(2)	5	3
Unrealized (losses) gains on available-for-sale securities		2	(5)	10
Other Comprehensive Income, net of tax	4	2	13	13
Comprehensive Income	1,070	957	2,203	2,374
Less: Comprehensive (Loss) Income Attributable to Noncontrolling Interests	(16)	1	(12)	5
Comprehensive Income Attributable to Duke Energy Corporation	$ 1,086	$ 956	$ 2,215	$ 2,369
Income from continuing operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	$ 1.51	$ 1.36	$ 3.12	$ 3.37
Diluted (usd per share)	1.51	1.36	3.11	3.37
Loss from discontinued operations attributable to Duke Energy Corporation common stockholders
Basic (usd per share)				(0.01)
Diluted (usd per share)				(0.01)
Net income attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	1.51	1.36	3.12	3.36
Diluted (usd per share)	$ 1.51	$ 1.36	$ 3.11	$ 3.36
Weighted average shares outstanding
Basic (shares)	713	700	705	700
Diluted (shares)	714	700	706	700
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 2,090	$ 2,136	$ 5,525	$ 5,581
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	490	531	1,370	1,394
Operation, maintenance and other	514	494	1,464	1,472
Depreciation and amortization	305	281	866	804
Property and other taxes	67	67	214	206
Impairment charges	1		191
Total operating expenses	1,377	1,373	4,105	3,876
Gains (Losses) on Sales of Other Assets and Other, net			(1)
Operating Income	713	763	1,419	1,705
Other Income and Expenses
Total other income and expenses	34	40	108	140
Interest Expense	106	108	323	314
Income From Continuing Operations Before Income Taxes	641	695	1,204	1,531
Income Tax Expense From Continuing Operations	145	229	268	522
Net Income Attributable to Duke Energy Corporation	496	466	936	1,009
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges			1	1
Other Comprehensive Income, net of tax			1	1
Comprehensive Income Attributable to Duke Energy Corporation	496	466	937	1,010
Progress Energy [Member]
Operating Revenues
Total operating revenues	3,045	2,864	8,119	7,435
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	1,148	1,031	3,019	2,588
Operation, maintenance and other	680	588	1,913	1,697
Depreciation and amortization	419	334	1,183	958
Property and other taxes	145	140	399	386
Impairment charges	1	135	34	137
Total operating expenses	2,393	2,228	6,548	5,766
Gains (Losses) on Sales of Other Assets and Other, net	11	5	23	19
Operating Income	663	641	1,594	1,688
Other Income and Expenses
Total other income and expenses	51	36	128	112
Interest Expense	214	193	626	595
Income From Continuing Operations Before Income Taxes	500	484	1,096	1,205
Income Tax Expense From Continuing Operations	94	141	186	384
Net Income	406	343	910	821
Less: Net (Loss) Income Attributable to Noncontrolling Interests	2	2	6	7
Net Income Attributable to Duke Energy Corporation	404	341	904	814
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments		3	2	5
Net unrealized (losses) gains on cash flow hedges	2	(2)	5	4
Unrealized (losses) gains on available-for-sale securities		1	(1)	3
Other Comprehensive Income, net of tax	2	2	6	12
Comprehensive Income	408	345	916	833
Less: Comprehensive (Loss) Income Attributable to Noncontrolling Interests	2	2	6	7
Comprehensive Income Attributable to Duke Energy Corporation	406	343	910	826
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,582	1,460	4,333	3,878
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	535	475	1,452	1,214
Operation, maintenance and other	431	365	1,187	1,069
Depreciation and amortization	253	182	723	536
Property and other taxes	40	40	115	120
Impairment charges			33
Total operating expenses	1,259	1,062	3,510	2,939
Gains (Losses) on Sales of Other Assets and Other, net	7		9	3
Operating Income	330	398	832	942
Other Income and Expenses
Total other income and expenses	24	27	61	84
Interest Expense	82	65	241	217
Income From Continuing Operations Before Income Taxes	272	360	652	809
Income Tax Expense From Continuing Operations	56	114	120	262
Net Income Attributable to Duke Energy Corporation	216	246	532	547
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation	216	246	532	547
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,462	1,401	3,780	3,551
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	614	557	1,567	1,374
Operation, maintenance and other	245	220	719	623
Depreciation and amortization	166	154	460	423
Property and other taxes	105	99	284	265
Impairment charges	1	135	1	137
Total operating expenses	1,131	1,165	3,031	2,822
Operating Income	331	236	749	729
Other Income and Expenses
Total other income and expenses	28	19	75	58
Interest Expense	73	71	210	211
Income From Continuing Operations Before Income Taxes	286	184	614	576
Income Tax Expense From Continuing Operations	43	64	100	208
Net Income Attributable to Duke Energy Corporation	243	120	514	368
Other Comprehensive Income (Loss), net of tax
Unrealized (losses) gains on available-for-sale securities		1	(1)	3
Other Comprehensive Income, net of tax			(1)	3
Comprehensive Income Attributable to Duke Energy Corporation	243	121	513	371
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	373	371	1,055	1,036
Regulated natural gas	84	90	361	360
Nonregulated electric and other	12	10	36	30
Total operating revenues	469	471	1,452	1,426
Operating Expenses
Operation, maintenance and other	76	125	337	388
Depreciation and amortization	64	63	196	193
Property and other taxes	73	65	218	204
Impairment charges				1
Total operating expenses	330	371	1,151	1,180
Gains (Losses) on Sales of Other Assets and Other, net		1	(106)	1
Operating Income	139	101	195	247
Other Income and Expenses
Total other income and expenses	3	5	17	15
Interest Expense	23	22	68	67
Income From Continuing Operations Before Income Taxes	119	84	144	195
Income Tax Expense From Continuing Operations	19	28	23	67
Income From Continuing Operations	100	56	121	128
Income (Loss) From Discontinued Operations, net of tax		(1)		(1)
Net Income				127
Net Income Attributable to Duke Energy Corporation	100	55	121	127
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation	100	55	121	127
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	819	802	2,288	2,302
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	272	259	730	744
Operation, maintenance and other	198	177	576	546
Depreciation and amortization	130	120	386	336
Property and other taxes	16	19	56	56
Impairment charges	30		30
Total operating expenses	646	575	1,778	1,682
Gains (Losses) on Sales of Other Assets and Other, net		1		1
Operating Income	173	228	510	621
Other Income and Expenses
Total other income and expenses	23	12	36	32
Interest Expense	42	44	125	132
Income From Continuing Operations Before Income Taxes	154	196	421	521
Income Tax Expense From Continuing Operations	35	75	104	203
Net Income Attributable to Duke Energy Corporation	119	121	317	318
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation	119	121	317	318
Piedmont Natural Gas [Member]
Operating Revenues
Total operating revenues	172	183	940	884
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	54	63	387	333
Operation, maintenance and other	85	73	252	226
Depreciation and amortization	40	38	118	109
Property and other taxes	12	13	36	38
Impairment charges				7
Total operating expenses	191	187	793	713
Operating Income	(19)	(4)	147	171
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	3	3	6	8
Other income and expenses, net	3	0	9	(1)
Total other income and expenses	6	3	15	7
Interest Expense	19	20	60	59
Income From Continuing Operations Before Income Taxes	(32)	(21)	102	119
Income Tax Expense From Continuing Operations	(11)	(10)	21	43
Net Income Attributable to Duke Energy Corporation	(21)	(11)	81	76
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Duke Energy Corporation	(21)	(11)	81	76
Electricity, US Regulated [Member] | Duke Energy Ohio [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	99	100	284	283
Electricity, Nonregulated [Member] | Duke Energy Ohio [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	14	13	43	42
Electricity [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	1,931	1,863	5,181	4,853
Natural Gas [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	58	68	460	402
Natural Gas [Member] | Duke Energy Ohio [Member]
Operating Expenses
Fuel used in electric generation and purchased power/Cost of natural gas	$ 4	$ 5	$ 73	$ 69