Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Loss From Discontinued Operations, net of tax		$ (5)	$ 0	$ (5)
Operating revenues	$ 5,873	5,643	12,036	11,778
Segment income (loss)	820	505	1,720	1,125
Add back noncontrolling interests(a)	(84)	2	(91)	4
Add back preferred stock dividend	12		12
Net Income	748	502	1,641	1,124
Net income (attributable to parent)	820	500	1,720	1,120
Segment assets	153,449		153,449		$ 145,392
Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,467	5,215	10,788	10,530
Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	282	294	1,014	997
Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	118	119	224	220
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,867	5,628	12,026	11,747
Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	6	15	10	31
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	935	641	1,924	1,527
Segment assets	149,453		149,453
Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,475	5,223	10,804	10,546
Segment income (loss)	809	575	1,559	1,325
Segment assets	131,640		131,640
Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	306	318	1,062	1,045
Segment income (loss)	40	28	266	144
Segment assets	12,943		12,943
Operating Segments [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	118	119	224	220
Segment income (loss)	86	38	99	58
Segment assets	4,870		4,870
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,899	5,660	12,090	11,811
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(51)	(49)	(100)	(100)
Segment assets	181		181
Intersegment Eliminations [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	8	8	16	16
Intersegment Eliminations [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	24	24	48	48
Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	32	32	64	64
Intersegment Eliminations [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	19	17	36	36
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	(115)	(136)	(204)	(402)
Segment assets	3,815		3,815
Corporate, Non-Segment [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating revenues	25	32	46	67
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	433	459	964	983
Segment income (loss)	47	46	116	21
Net income (attributable to parent)	47	46	116	21
Segment assets	8,889		8,889		$ 8,555
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	336	346	691	682
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	97	103	273	277
Duke Energy Ohio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	433	449	964	959
Segment income (loss)	48	57	119	124
Segment assets	8,862		8,862
Duke Energy Ohio [Member] | Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	31	39	67	72
Segment assets	5,914		5,914
Duke Energy Ohio [Member] | Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	17	18	52	52
Segment assets	2,948		2,948
Duke Energy Ohio [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues		10		24
Segment income (loss)	(1)	$ (11)	(3)	$ (103)
Segment assets	$ 27		$ 27