Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - USD ($)	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Tax-exempt bonds	$ (360,000,000)		$ (477,000,000)
Duke Energy Progress
Line of Credit Facility [Line Items]
Tax-exempt bonds	(48,000,000)		(48,000,000)
Duke Energy Ohio
Line of Credit Facility [Line Items]
Tax-exempt bonds	(27,000,000)		(77,000,000)
Duke Energy Indiana
Line of Credit Facility [Line Items]
Tax-exempt bonds	(285,000,000)		$ (352,000,000)
Revolving Credit Facility
Line of Credit Facility [Line Items]
Facility size	8,000,000,000	$ 8,000,000,000
Commercial paper	(2,863,000,000)
Outstanding letters of credit	(38,000,000)
Tax-exempt bonds	(81,000,000)
Available capacity	5,018,000,000
Revolving Credit Facility | Parent Company
Line of Credit Facility [Line Items]
Facility size	2,650,000,000
Commercial paper	(1,128,000,000)
Outstanding letters of credit	(25,000,000)
Available capacity	1,497,000,000
Revolving Credit Facility | Duke Energy Carolinas
Line of Credit Facility [Line Items]
Facility size	1,225,000,000
Commercial paper	(506,000,000)
Outstanding letters of credit	(4,000,000)
Available capacity	715,000,000
Revolving Credit Facility | Duke Energy Progress
Line of Credit Facility [Line Items]
Facility size	1,150,000,000
Commercial paper	(307,000,000)
Outstanding letters of credit	(2,000,000)
Available capacity	841,000,000
Revolving Credit Facility | Duke Energy Florida
Line of Credit Facility [Line Items]
Facility size	900,000,000
Commercial paper	(181,000,000)
Outstanding letters of credit	(7,000,000)
Available capacity	712,000,000
Revolving Credit Facility | Duke Energy Ohio
Line of Credit Facility [Line Items]
Facility size	775,000,000
Commercial paper	(119,000,000)
Available capacity	656,000,000
Revolving Credit Facility | 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	369,000,000
Revolving Credit Facility | Piedmont
Line of Credit Facility [Line Items]
Facility size	700,000,000
Commercial paper	(472,000,000)
Available capacity	228,000,000
Proceeds Loaned To Subsidiary Registrants | Revolving Credit Facility | Parent Company
Line of Credit Facility [Line Items]
Commercial paper	$ (625,000,000)