Summary of Significant Accounting Policies (Excise Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization And Basis Of Presentation [Line Items]
Excise taxes	$ 420	$ 415	$ 421
Duke Energy Carolinas
Organization And Basis Of Presentation [Line Items]
Excise taxes	44	43	39
Progress Energy
Organization And Basis Of Presentation [Line Items]
Excise taxes	250	249	256
Duke Energy Progress
Organization And Basis Of Presentation [Line Items]
Excise taxes	22	26	21
Duke Energy Florida
Organization And Basis Of Presentation [Line Items]
Excise taxes	228	223	235
Duke Energy Ohio
Organization And Basis Of Presentation [Line Items]
Excise taxes	102	96	101
Duke Energy Indiana
Organization And Basis Of Presentation [Line Items]
Excise taxes	23	25	23
Piedmont
Organization And Basis Of Presentation [Line Items]
Excise taxes	$ 1	$ 2	$ 2