v3.26.1
VARIABLE INTEREST ENTITIES (Details)
$ in Millions
Jun. 30, 2026
USD ($)
subsidiary
Dec. 31, 2025
USD ($)
Feb. 02, 2023
Jun. 30, 2013
USD ($)
Variable Interest Entity [Line Items]        
Number of subsidiaries that issued environmental control bonds | subsidiary 2      
Long-term pollution control bond $ 139 $ 156    
Restricted cash $ 128 42    
FET        
Variable Interest Entity [Line Items]        
Noncontrolling interest, ownership percentage by noncontrolling owners 49.90%      
FET | Brookfield        
Variable Interest Entity [Line Items]        
Sale of ownership interest by parent     30.00%  
Phase In Recovery Bonds        
Variable Interest Entity [Line Items]        
Long-term debt $ 150 159    
Ohio Funding Companies | Phase In Recovery Bonds        
Variable Interest Entity [Line Items]        
Face amount of debt       $ 445
MP, PE and the Ohio Companies        
Variable Interest Entity [Line Items]        
Restricted cash $ 41 $ 40    
FE | FET        
Variable Interest Entity [Line Items]        
Ownership percentage by parent 50.10%