Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues	$ 6,103	$ 6,940	$ 5,873	$ 6,163	$ 6,115	$ 6,628	$ 5,643	$ 6,135	$ 25,079	$ 24,521	$ 23,565
Interest expense									2,204	2,094	1,986
Depreciation and amortization									4,548	4,074	3,527
Equity in earnings of unconsolidated affiliates									162	83	119
Income tax expense (benefit) from continuing operations									519	448	1,196
Segment income (loss)									3,714	2,647	3,065
Add back noncontrolling interests component									(177)	(22)	5
Add back preferred stock dividend									41
(Loss) Income From Discontinued Operations, net of tax	(7)				20	4	(5)	0	(7)	19	(6)
Net income (loss)	607	1,323	748	893	454	1,066	502	622	3,571	2,644	3,064
Net income (loss) attributable to parent					464	1,082	500	620	3,748	2,666	3,059
Capital expenditures									11,446	9,668	8,198
Segment assets	158,838				145,392				158,838	145,392	137,914
Segment Reporting Information Assets [Abstract]
Reduction of prior year impairment	(14)	25							11
After-tax severance charges					187				16	187	15
After-tax loss on sale and retirement								(107)		(107)
Duke Energy Ohio
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues	487	489	433	531	505	469	459	524	1,940	1,957	1,923
Interest expense									109	92	91
Depreciation and amortization									265	268	261
Income tax expense (benefit) from continuing operations									40	43	59
Segment income (loss)									239	176	193
(Loss) Income From Discontinued Operations, net of tax									(1)		(1)
Net income (loss) attributable to parent	48	$ 74	$ 47	$ 69	55	$ 100	46	(25)	238	176	192
Capital expenditures									952	827	686
Segment assets	9,338				8,555				9,338	8,555	7,875
Segment Reporting Information Assets [Abstract]
Tax Act					2					2
After-tax severance charges					6					6
After-tax loss on sale and retirement								107		107
Regulatory settlements
Segment Reporting Information Assets [Abstract]
Regulatory settlement charges							$ 179	$ 86		265
Noncontrolling Interests
Segment Reporting Information, Profit (Loss) [Abstract]
Net income (loss)										(22)	5
Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									(200)	(199)	(200)
Interest expense									(58)	(45)	(20)
Depreciation and amortization									(5)	(1)
Segment assets	188				188				188	188	188
Eliminations | Duke Energy Ohio
Segment Reporting Information, Profit (Loss) [Abstract]
Segment assets											(15)
Electric Utilities and Infrastructure
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									22,798	22,242	21,300
Equity in earnings of unconsolidated affiliates									9	6	5
Segment Reporting Information Assets [Abstract]
Tax Act										24	231
Electric Utilities and Infrastructure | After-tax impairment charge
Segment Reporting Information Assets [Abstract]
After tax impairment charge										46
Electric Utilities and Infrastructure | Regulatory settlements
Segment Reporting Information Assets [Abstract]
Regulatory settlement charges										202	98
Electric Utilities and Infrastructure | Operating Segments
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									22,831	22,273	21,331
Interest expense									1,345	1,288	1,240
Depreciation and amortization									3,951	3,523	3,010
Equity in earnings of unconsolidated affiliates									9	5	5
Income tax expense (benefit) from continuing operations									785	799	1,355
Segment income (loss)									3,536	3,058	3,210
Capital expenditures									8,263	8,086	7,024
Segment assets	135,561				125,364				135,561	125,364	119,423
Segment Reporting Information Assets [Abstract]
Reduction of prior year impairment									27
Electric Utilities and Infrastructure | Operating Segments | Duke Energy Ohio
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									1,456	1,450	1,373
Interest expense									80	67	62
Depreciation and amortization									182	183	178
Income tax expense (benefit) from continuing operations									20	47	40
Segment income (loss)									159	186	138
Capital expenditures									680	655	491
Segment assets	6,188				5,643				6,188	5,643	5,066
Electric Utilities and Infrastructure | Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									33	31	31
Gas Utilities and Infrastructure
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									1,770	1,783	1,743
Equity in earnings of unconsolidated affiliates									114	27	62
Segment Reporting Information Assets [Abstract]
Tax Act										1	26
Gas Utilities and Infrastructure | After-tax impairment charge
Segment Reporting Information Assets [Abstract]
After tax impairment charge									19	42
Gas Utilities and Infrastructure | Operating Segments
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									1,866	1,881	1,836
Interest expense									117	106	105
Depreciation and amortization									256	245	231
Equity in earnings of unconsolidated affiliates									114	27	62
Income tax expense (benefit) from continuing operations									22	78	116
Segment income (loss)									432	274	319
Capital expenditures									1,539	1,133	907
Segment assets	13,921				12,361				13,921	12,361	11,462
Gas Utilities and Infrastructure | Operating Segments | Duke Energy Ohio
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									484	506	508
Interest expense									29	24	28
Depreciation and amortization									83	85	83
Income tax expense (benefit) from continuing operations									21	24	39
Segment income (loss)									85	93	85
Capital expenditures									272	172	195
Segment assets	3,116				2,874				3,116	2,874	2,758
Gas Utilities and Infrastructure | Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									96	98	93
Commercial Renewables
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									487	477	460
Equity in earnings of unconsolidated affiliates									(4)	(1)	(5)
Segment Reporting Information Assets [Abstract]
After tax impairment charge										91	74
Tax Act										3	442
Commercial Renewables | Noncontrolling Interests
Segment Reporting Information Assets [Abstract]
After tax impairment charge										2
Commercial Renewables | Operating Segments
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									487	477	460
Interest expense									95	88	87
Depreciation and amortization									168	155	155
Equity in earnings of unconsolidated affiliates									(4)	(1)	(5)
Income tax expense (benefit) from continuing operations									(115)	(147)	(628)
Segment income (loss)									198	9	441
Capital expenditures									1,423	193	92
Segment assets	6,020				4,204				6,020	4,204	4,156
Commercial Renewables | Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									0		0
Other
Segment Reporting Information, Profit (Loss) [Abstract]
Equity in earnings of unconsolidated affiliates									43	51	57
Segment Reporting Information Assets [Abstract]
After-tax severance charges										144
After-tax loss on sale and retirement										82
Total Reportable Segments
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									25,055	24,502	23,503
Total Reportable Segments | Operating Segments
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									25,184	24,631	23,627
Interest expense									1,557	1,482	1,432
Depreciation and amortization									4,375	3,923	3,396
Equity in earnings of unconsolidated affiliates									119	31	62
Income tax expense (benefit) from continuing operations									692	730	843
Segment income (loss)									4,166	3,341	3,970
Capital expenditures									11,225	9,412	8,023
Segment assets	155,502				141,929				155,502	141,929	135,041
Total Reportable Segments | Operating Segments | Duke Energy Ohio
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									1,940	1,956	1,881
Interest expense									109	91	90
Depreciation and amortization									265	268	261
Income tax expense (benefit) from continuing operations									41	71	79
Segment income (loss)									244	279	223
Capital expenditures									952	827	686
Segment assets	9,304				8,517				9,304	8,517	7,824
Total Reportable Segments | Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									129	129	124
Other
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									24	19	62
Segment Reporting Information Assets [Abstract]
Tax Act										2	597
Costs to achieve mergers, acquisition costs										65	64
Other | Eliminations
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									71	70	76
Other | Other
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues									95	89	138
Interest expense									705	657	574
Depreciation and amortization									178	152	131
Equity in earnings of unconsolidated affiliates									43	52	57
Income tax expense (benefit) from continuing operations									(173)	(282)	353
Segment income (loss)									(452)	(694)	(905)
Capital expenditures									221	256	175
Segment assets	3,148				3,275				3,148	3,275	2,685
Other | Other | Duke Energy Ohio
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues										1	42
Interest expense										1	1
Income tax expense (benefit) from continuing operations									(1)	(28)	(20)
Segment income (loss)									(5)	(103)	(30)
Segment assets	$ 34				$ 38				$ 34	$ 38	$ 66