v3.26.1
FAIR VALUE MEASUREMENTS - Schedule of Fair Value and Related Carrying Amounts of Long-term Debt (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Carrying value    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt $ 27,771 $ 26,390
Carrying value | JCP&L    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt 3,400 3,050
Fair value    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt 26,887 25,756
Fair value | JCP&L    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt $ 3,358 $ 3,059