Investments in Debt and Equity Securities (Maturities) (Details) $ in Millions	Dec. 31, 2024 USD ($)
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	$ 89
Due after one through five years	791
Due after five through 10 years	721
Due after 10 years	1,725
Total	3,326
Duke Energy Carolinas
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	9
Due after one through five years	303
Due after five through 10 years	441
Due after 10 years	898
Total	1,651
Progress Energy
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	62
Due after one through five years	408
Due after five through 10 years	234
Due after 10 years	729
Total	1,433
Duke Energy Progress
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	12
Due after one through five years	310
Due after five through 10 years	219
Due after 10 years	680
Total	1,221
Duke Energy Florida
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	50
Due after one through five years	98
Due after five through 10 years	15
Due after 10 years	49
Total	212
Duke Energy Indiana
Debt Securities, Available-for-sale [Line Items]
Due in one year or less	4
Due after one through five years	20
Due after five through 10 years	12
Due after 10 years	20
Total	$ 56