Debt and Credit Facilities (Narrative) (Details) - Master Credit Facility - USD ($)	1 Months Ended
	Oct. 31, 2021	Sep. 30, 2021	Mar. 31, 2021
Debt Instrument [Line Items]
Facility size		$ 8,000,000,000	$ 8,000,000,000
Duke Energy Ohio
Debt Instrument [Line Items]
Facility size		775,000,000
Duke Energy Indiana
Debt Instrument [Line Items]
Facility size		$ 600,000,000
Subsequent event | Term Loan Facility | Duke Energy Ohio
Debt Instrument [Line Items]
Facility size	$ 100,000,000
Facility term	2 years
Subsequent event | Term Loan Facility | Duke Energy Kentucky
Debt Instrument [Line Items]
Facility size	$ 50,000,000
Facility term	2 years
Subsequent event | Term Loan Facility | Duke Energy Indiana
Debt Instrument [Line Items]
Facility size	$ 300,000,000
Facility term	2 years