v3.26.1
Leases (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Lessee, Lease, Description [Line Items]          
Finance lease, right-of-use asset $ 141   $ 141   $ 142
Operating lease, expense 3 $ 3 6 $ 6  
Operating lease payments 3 3 6 6  
Right-of-use asset obtained in exchange for operating lease liability $ 0 $ 4 $ 1 $ 7  
Operating lease, weighted-average remaining lease term 18 years   18 years   18 years
Operating lease, weighted-average discount rate 5.00%   5.00%   5.00%
Payments, remainder of fiscal year $ 5   $ 5    
Payments, year one 10   10    
Payments, year two 8   8    
Payments, year three 8   8    
Payments, year four 7   7    
Thereafter 84   84    
Imputed interest 45   45    
Operating and Maintenance Agreement          
Lessee, Lease, Description [Line Items]          
Future minimum sublease rentals, remainder of fiscal year 2   2    
Future minimum sublease rentals, year one 4   4    
Future minimum sublease rentals, year two 4   4    
Future minimum sublease rentals, year three 4   4    
Future minimum sublease rentals, year four 4   4    
Future minimum sublease rentals, thereafter $ 33   $ 33    
Real Property          
Lessee, Lease, Description [Line Items]          
Operating lease, term of contract 59 years   59 years    
Vehicles          
Lessee, Lease, Description [Line Items]          
Operating lease, term of contract 4 years   4 years    
Equipment          
Lessee, Lease, Description [Line Items]          
Operating lease, term of contract 5 years   5 years    
Minimum          
Lessee, Lease, Description [Line Items]          
Operating lease, renewal term 1 year   1 year    
Minimum | Utility Plant          
Lessee, Lease, Description [Line Items]          
Lessee, finance lease, term of contract 30 years   30 years    
Maximum          
Lessee, Lease, Description [Line Items]          
Operating lease, renewal term 60 years   60 years    
Maximum | Utility Plant          
Lessee, Lease, Description [Line Items]          
Lessee, finance lease, term of contract 40 years   40 years