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