v3.26.1
ASSET RETIREMENT OBLIGATIONS - Schedule of Changes to the ARO Balances (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Beginning balance $ 277 $ 455
Changes in timing and amount of estimated cash flows (10) (51)
Liabilities incurred   1
Liabilities settled (1) (154)
Accretion 12 26
Ending balance 278 277
JCP&L    
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]    
Beginning balance 8 8
Changes in timing and amount of estimated cash flows 0 0
Liabilities incurred   0
Liabilities settled 0 0
Accretion 0 0
Ending balance $ 8 $ 8