Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Variable Interest Entities [Line Items]
Long-Term Debt	$ 57,929,000,000	$ 55,625,000,000
Duke Energy Carolinas
Variable Interest Entities [Line Items]
Long-Term Debt	12,318,000,000	11,412,000,000
Duke Energy Progress
Variable Interest Entities [Line Items]
Long-Term Debt	8,491,000,000	8,505,000,000
Duke Energy Florida
Variable Interest Entities [Line Items]
Long-Term Debt	7,273,000,000	7,092,000,000
CRC | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	350,000,000
Long-Term Debt	350,000,000	350,000,000
Accounts receivable from securitization	535,000,000	547,000,000
DERF | Duke Energy Carolinas | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	475,000,000
Long-Term Debt	475,000,000	364,000,000
Accounts receivable from securitization	915,000,000	696,000,000
DEPR | Duke Energy Progress | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	350,000,000
Long-Term Debt	350,000,000	250,000,000
Accounts receivable from securitization	532,000,000	500,000,000
DEFR | Duke Energy Florida | VIE primary beneficiary
Variable Interest Entities [Line Items]
Facility size	250,000,000
Long-Term Debt	250,000,000	250,000,000
Accounts receivable from securitization	$ 443,000,000	$ 397,000,000