Severance (Expenses) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) employee	Dec. 31, 2020 USD ($) employee	Dec. 31, 2019 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Number of eligible employees | employee	290	30	140
Severance expense	$ 69	$ (85)	$ 16
Amortization of deferred severance charges	33
Severance charges adjustments	(3)	(6)
Unamortized deferred severance		(86)
Duke Energy Carolinas
Restructuring Cost and Reserve [Line Items]
Severance expense	33	(58)	8
Amortization of deferred severance charges	22
Severance charges adjustments	(2)	(2)
Unamortized deferred severance		(57)
Progress Energy
Restructuring Cost and Reserve [Line Items]
Severance expense	26	(28)	6
Amortization of deferred severance charges	11
Severance charges adjustments		(3)
Unamortized deferred severance		(29)
Duke Energy Progress
Restructuring Cost and Reserve [Line Items]
Severance expense	20	(31)	3
Amortization of deferred severance charges	11
Severance charges adjustments		(2)
Unamortized deferred severance		(29)
Duke Energy Florida
Restructuring Cost and Reserve [Line Items]
Severance expense	6	$ 3	3
Duke Energy Ohio
Restructuring Cost and Reserve [Line Items]
Severance expense	2
Duke Energy Indiana
Restructuring Cost and Reserve [Line Items]
Severance expense	3		1
Severance charges adjustments	(1)
Piedmont
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 2		$ 1