v3.26.3
Variable Interest Entities (Narrative) (Details)
$ in Millions
1 Months Ended 9 Months Ended
Oct. 27, 2026
USD ($)
Jun. 30, 2026
MW
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Variable Interest Entity [Line Items]          
Deemed contribution from sale of membership interest     $ 166 $ 0  
Securitization bonds          
Variable Interest Entity [Line Items]          
Total principal amount outstanding     479   $ 585
Variable Interest Entity, Primary Beneficiary          
Variable Interest Entity [Line Items]          
Regulatory asset     458   $ 549
Variable Interest Entity, Primary Beneficiary | HL Solar Holdings          
Variable Interest Entity [Line Items]          
Proceeds from the sale of membership interests in VIEs     24    
Deemed contribution from sale of membership interest     $ 166    
Variable Interest Entity, Primary Beneficiary | HL Solar Holdings | Subsequent Event          
Variable Interest Entity [Line Items]          
Proceeds from the sale of membership interests in VIEs $ 34        
St. Clair County | Variable Interest Entity, Primary Beneficiary | HL Solar Holdings          
Variable Interest Entity [Line Items]          
Nameplate capacity (in MW) | MW   100      
Hart Township | Variable Interest Entity, Primary Beneficiary | HL Solar Holdings          
Variable Interest Entity [Line Items]          
Nameplate capacity (in MW) | MW   120