Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating revenues	$ 5,758	$ 5,421	$ 11,908	$ 11,370
Segment income (loss)	751	(817)	1,704	82
Less: Noncontrolling interests	67	90	118	138
Add: Preferred stock dividend	14	15	53	54
Net Income (Loss)	698	(892)	1,639	(2)
Segment assets	165,385		165,385		$ 162,388
Nonregulated electric and other	198	195	380	382
Incurred costs	1,410	1,353	2,812	2,692
Equity in earnings (losses) of unconsolidated affiliates	(9)	1,968	8	1,924
Impairment of assets and other charges	131	6	131	8
Income before taxes	734	(1,208)	1,759	(181)
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	456	423	988	921
Segment income (loss)	39	66	130	131
Segment assets	10,322		10,322		$ 10,025
Incurred costs	111	95	219	218
Impairment of assets and other charges	5		5
Income before taxes	50	78	155	157
Impairment charges
Segment Reporting Information [Line Items]
Impairment of assets and other charges	131		131
Operations, maintenance and other
Segment Reporting Information [Line Items]
Impairment of assets and other charges	27		27
Depreciation and amortization
Segment Reporting Information [Line Items]
Impairment of assets and other charges	17		17
Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	5,328	5,026	10,601	10,200
Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	305	265	1,057	905
Gas Utilities and Infrastructure | Asset Impairment for Regulatory Action
Segment Reporting Information [Line Items]
Equity in earnings (losses) of unconsolidated affiliates	16		22
Commercial Renewables
Segment Reporting Information [Line Items]
Operating revenues	119	123	238	252
Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	5,752	5,414	11,896	11,357
Other
Segment Reporting Information [Line Items]
Operating revenues	6	7	12	13
Severance charge reversal		2,000
Operating Segments | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	5,335	5,034	10,616	10,217
Segment income (loss)	935	753	1,755	1,458
Segment assets	140,591		140,591
Operating Segments | Electric Utilities and Infrastructure | Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	343	330	706	676
Segment income (loss)	24	44	74	74
Segment assets	6,645		6,645
Operating Segments | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	327	289	1,102	953
Segment income (loss)	17	(1,576)	262	(1,327)
Segment assets	14,321		14,321
Equity in earnings (losses) of unconsolidated affiliates				(2,000)
Operating Segments | Gas Utilities and Infrastructure | Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	113	93	282	245
Segment income (loss)	23	23	66	59
Segment assets	3,668		3,668
Operating Segments | Commercial Renewables
Segment Reporting Information [Line Items]
Operating revenues	119	123	238	252
Segment income (loss)	47	90	74	147
Segment assets	6,956		6,956
Operating Segments | Commercial Renewables | Texas Storm Uri
Segment Reporting Information [Line Items]
Net Income (Loss)			12
Nonregulated electric and other			8
Incurred costs			2
Equity in earnings (losses) of unconsolidated affiliates			(29)
Income before taxes			(35)
Operating Segments | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	5,781	5,446	11,956	11,422
Segment income (loss)	999	(733)	2,091	278
Segment assets	161,868		161,868
Operating Segments | Total Reportable Segments | Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	456	423	988	921
Segment income (loss)	47	67	140	133
Segment assets	10,313		10,313
Other
Segment Reporting Information [Line Items]
Income before taxes				98
Other | Other
Segment Reporting Information [Line Items]
Operating revenues	27	26	53	49
Segment income (loss)	(248)	(84)	(387)	(196)
Segment assets	3,524		3,524
Other | Other | Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	(8)	(1)	(10)	(2)
Segment assets	28		28
Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(50)	(51)	(101)	(101)
Segment assets	(7)		(7)
Eliminations | Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Segment assets	(19)		(19)
Eliminations | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	7	8	15	17
Eliminations | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Operating revenues	22	24	45	48
Eliminations | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues	29	32	60	65
Eliminations | Other
Segment Reporting Information [Line Items]
Operating revenues	$ 21	$ 19	$ 41	$ 36