Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - Master Credit Facility - USD ($)	Mar. 31, 2022	Mar. 31, 2021
Line of Credit Facility [Line Items]
Facility size	$ 9,000,000,000	$ 8,000,000,000
Commercial paper	(2,819,000,000)
Outstanding letters of credit	(38,000,000)
Tax-exempt bonds	(81,000,000)
Available capacity under the Master Credit Facility	6,062,000,000
Duke Energy Carolinas
Line of Credit Facility [Line Items]
Facility size	1,225,000,000
Commercial paper	(300,000,000)
Outstanding letters of credit	(4,000,000)
Available capacity under the Master Credit Facility	921,000,000
Duke Energy Progress
Line of Credit Facility [Line Items]
Facility size	1,400,000,000
Commercial paper	(150,000,000)
Outstanding letters of credit	(2,000,000)
Available capacity under the Master Credit Facility	1,248,000,000
Duke Energy Florida
Line of Credit Facility [Line Items]
Facility size	900,000,000
Commercial paper	(236,000,000)
Outstanding letters of credit	(7,000,000)
Available capacity under the Master Credit Facility	657,000,000
Duke Energy Ohio
Line of Credit Facility [Line Items]
Facility size	775,000,000
Commercial paper	(86,000,000)
Available capacity under the Master Credit Facility	689,000,000
Duke Energy Indiana
Line of Credit Facility [Line Items]
Facility size	600,000,000
Commercial paper	(150,000,000)
Tax-exempt bonds	(81,000,000)
Available capacity under the Master Credit Facility	369,000,000
Piedmont
Line of Credit Facility [Line Items]
Facility size	800,000,000
Commercial paper	(182,000,000)
Available capacity under the Master Credit Facility	618,000,000
Duke Energy (Parent) | Proceeds loaned to subsidiary registrants
Line of Credit Facility [Line Items]
Commercial paper	(625,000,000)
Duke Energy (Parent) | Duke Energy (Parent)
Line of Credit Facility [Line Items]
Facility size	3,300,000,000
Commercial paper	(1,715,000,000)
Outstanding letters of credit	(25,000,000)
Available capacity under the Master Credit Facility	$ 1,560,000,000