v3.26.1
Employee Benefit Plans - Net Periodic Pension Costs (Details) - Qualified Pension Plans - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost $ 26 $ 27
Interest cost on projected benefit obligation 78 82
Expected return on plan assets (142) (149)
Amortization of actuarial loss 27 15
Amortization of prior service credit (1) (3)
Amortization of settlement charges 6 6
Net periodic pension costs (6) (22)
Duke Energy Carolinas    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 9 9
Interest cost on projected benefit obligation 19 19
Expected return on plan assets (36) (38)
Amortization of actuarial loss 6 4
Amortization of prior service credit 0 0
Amortization of settlement charges 3 3
Net periodic pension costs 1 (3)
Progress Energy    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 7 7
Interest cost on projected benefit obligation 25 26
Expected return on plan assets (53) (55)
Amortization of actuarial loss 9 5
Amortization of prior service credit 0 0
Amortization of settlement charges 2 2
Net periodic pension costs (10) (15)
Duke Energy Progress    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 4 5
Interest cost on projected benefit obligation 11 11
Expected return on plan assets (23) (24)
Amortization of actuarial loss 5 2
Amortization of prior service credit 0 0
Amortization of settlement charges 1 1
Net periodic pension costs (2) (5)
Duke Energy Florida    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 3 3
Interest cost on projected benefit obligation 14 14
Expected return on plan assets (30) (30)
Amortization of actuarial loss 5 2
Amortization of prior service credit 0 0
Amortization of settlement charges 1 1
Net periodic pension costs (7) (10)
Duke Energy Ohio    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 1 0
Interest cost on projected benefit obligation 4 4
Expected return on plan assets (6) (5)
Amortization of actuarial loss 1 1
Amortization of prior service credit 0 0
Amortization of settlement charges 0 0
Net periodic pension costs 0 0
Duke Energy Indiana    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 2 1
Interest cost on projected benefit obligation 6 7
Expected return on plan assets (10) (10)
Amortization of actuarial loss 2 1
Amortization of prior service credit 0 0
Amortization of settlement charges 0 0
Net periodic pension costs 0 (1)
Piedmont    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]    
Service cost 1 1
Interest cost on projected benefit obligation 2 3
Expected return on plan assets (5) (5)
Amortization of actuarial loss 2 1
Amortization of prior service credit (1) (2)
Amortization of settlement charges 1 1
Net periodic pension costs $ 0 $ (1)