v3.26.1
PENSION AND OTHER POST-EMPLOYMENT BENEFITS - Schedule of Components of Net Periodic Benefit Costs (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service costs $ 32 $ 32 $ 65 $ 65
Interest costs 87 94 174 187
Expected return on plan assets (114) (115) (229) (230)
Net periodic benefit costs (credits) 5 11 10 22
Net periodic benefit credits, net of amounts capitalized (14) (7) (28) (13)
Pension | JCP&L        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Net periodic benefit costs (credits) (2) (1) (4) (2)
Allocated net periodic benefit costs from affiliates 2 3 4 5
OPEB        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service costs 0 0 1 1
Interest costs 5 5 9 10
Expected return on plan assets (11) (9) (21) (19)
Net periodic benefit costs (credits) (6) (4) (11) (8)
Net periodic benefit credits, net of amounts capitalized (5) (5) (11) (9)
OPEB | JCP&L        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Net periodic benefit costs (credits) (5) (3) (9) (7)
Allocated net periodic benefit costs from affiliates $ 0 $ 0 $ 0 $ 0