Goodwill and Intangible Assets (Goodwill By Reportable Operating Segment) (Details) - USD ($)		12 Months Ended
	Aug. 31, 2020	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill, gross				$ 19,425,000,000	$ 19,425,000,000
Accumulated impairment charges				(122,000,000)	(122,000,000)
Goodwill, net				19,303,000,000	19,303,000,000
Impairment charges	$ 0
Electric Utilities and Infrastructure
Goodwill [Line Items]
Goodwill, gross				17,379,000,000	17,379,000,000
Goodwill, net				17,379,000,000	17,379,000,000
Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill, gross				1,924,000,000	1,924,000,000
Goodwill, net				1,924,000,000	1,924,000,000
Commercial Renewables
Goodwill [Line Items]
Goodwill, gross				122,000,000	122,000,000
Accumulated impairment charges				(122,000,000)	(122,000,000)
Impairment charges		$ 93,000,000	$ 29,000,000
Duke Energy Ohio
Goodwill [Line Items]
Accumulated impairment charges				(216,000,000)	(216,000,000)
Goodwill, net				920,000,000	920,000,000
Duke Energy Ohio | Electric Utilities and Infrastructure
Goodwill [Line Items]
Goodwill, net				596,000,000	596,000,000
Duke Energy Ohio | Gas Utilities and Infrastructure
Goodwill [Line Items]
Goodwill, net				324,000,000	324,000,000
Progress Energy
Goodwill [Line Items]
Goodwill, net				3,655,000,000	3,655,000,000
Progress Energy | Electric Utilities and Infrastructure
Goodwill [Line Items]
Accumulated impairment charges				0
Piedmont
Goodwill [Line Items]
Goodwill, net				49,000,000	$ 49,000,000
Piedmont | Gas Utilities and Infrastructure
Goodwill [Line Items]
Accumulated impairment charges				$ 0