Related Party Transactions (Intercompany Income Taxes) (Details) - Affiliated Entity - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Duke Energy Carolinas
Related Party Transaction [Line Items]
Intercompany income tax receivable	$ 80
Intercompany income tax payable		$ 62
Progress Energy
Related Party Transaction [Line Items]
Intercompany income tax receivable	114
Duke Energy Progress
Related Party Transaction [Line Items]
Intercompany income tax payable	33	84
Duke Energy Florida
Related Party Transaction [Line Items]
Intercompany income tax receivable	102	40
Duke Energy Ohio
Related Party Transaction [Line Items]
Intercompany income tax receivable	14	19
Duke Energy Indiana
Related Party Transaction [Line Items]
Intercompany income tax receivable	27
Intercompany income tax payable		10
Piedmont
Related Party Transaction [Line Items]
Intercompany income tax receivable	$ 25
Intercompany income tax payable		$ 27