v3.26.1
Investments in Debt and Equity Securities (Realized Gains and Losses) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
FV-NI:    
Realized gains $ 802 $ 126
Realized losses 124 41
AFS:    
Realized gains 17 10
Realized losses 16 20
Duke Energy Carolinas    
FV-NI:    
Realized gains 448 82
Realized losses 74 22
AFS:    
Realized gains 11 7
Realized losses 9 14
Progress Energy    
FV-NI:    
Realized gains 354 44
Realized losses 50 19
AFS:    
Realized gains 6 3
Realized losses 7 6
Duke Energy Progress    
FV-NI:    
Realized gains 354 44
Realized losses 50 19
AFS:    
Realized gains 6 3
Realized losses $ 7 $ 6