Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Income (Loss) From Discontinued Operations, net of tax		$ 4		$ (1)
Operating revenues	$ 6,940	6,628	$ 18,976	18,406
Segment income (loss)	1,327	1,078	3,047	2,203
Add back noncontrolling interests(b)	(19)	(16)	(110)	(12)
Add back preferred stock dividend	15		27
Net Income	1,323	1,066	2,964	2,190
Net income (attributable to parent)	1,327	1,082	3,047	2,202
Segment assets	155,917		155,917		$ 145,392
Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,569	6,253	17,357	16,783
Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	225	232	1,239	1,229
Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	138	127	362	347
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,932	6,612	18,958	18,359
Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	8	16	18	47
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	1,451	1,122	3,375	2,649
Segment assets	151,998		151,998
Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,577	6,260	17,381	16,806
Segment income (loss)	1,385	1,167	2,944	2,492
Segment assets	133,296		133,296
Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	249	256	1,311	1,301
Segment income (loss)	26	17	292	161
Segment assets	13,424		13,424
Operating Segments [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	138	127	362	347
Segment income (loss)	40	(62)	139	(4)
Segment assets	5,278		5,278
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,964	6,643	19,054	18,454
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(49)	(49)	(149)	(149)
Segment assets	185		185
Intersegment Eliminations [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	8	7	24	23
Intersegment Eliminations [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	24	24	72	72
Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	32	31	96	95
Intersegment Eliminations [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	17	18	53	54
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	(124)	(44)	(328)	(446)
Segment assets	3,734		3,734
Corporate, Non-Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	25	34	71	101
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	489	469	1,453	1,452
Segment income (loss)	74	100	190	121
Net income (attributable to parent)	74	100	190	121
Segment assets	9,183		9,183		$ 8,555
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	408	373	1,099	1,055
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	81	84	354	361
Duke Energy Ohio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	489	457	1,453	1,416
Segment income (loss)	75	97	194	221
Segment assets	9,156		9,156
Duke Energy Ohio [Member] | Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	62	85	129	157
Segment assets	6,107		6,107
Duke Energy Ohio [Member] | Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	13	12	65	64
Segment assets	3,049		3,049
Duke Energy Ohio [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Segment assets	(3)		(3)
Duke Energy Ohio [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues		12		36
Segment income (loss)	(1)	$ 3	(4)	$ (100)
Segment assets	$ 30		$ 30