v3.25.2
Commitments and Contingencies - Leases (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Lessee, Lease, Description [Line Items]          
Operating Lease, Cost $ 28 [1] $ 28 [1] $ 59 [2] $ 56 [2]  
Lessee, Operating Lease, Liability, to be Paid 503   503    
Lessee, Operating Lease, Liability, Undiscounted Excess Amount (138)   (138)    
Operating Lease, Liability 365   365    
Operating Lease, Liability, Current (100)   (100)   $ (97)
Operating lease liabilities 265   265   $ 317
Purchased Power Agreements          
Lessee, Lease, Description [Line Items]          
Operating Lease, Cost 25 25 50 48  
Lessee, Operating Lease, Liability, to be Paid 252   252    
Lessee, Operating Lease, Liability, Undiscounted Excess Amount (16)   (16)    
Operating Lease, Liability 236   236    
Property, Plant and Equipment, Other Types          
Lessee, Lease, Description [Line Items]          
Operating Lease, Cost 3 [3] $ 3 [3] 9 [4] $ 8 [4]  
Lessee, Operating Lease, Liability, to be Paid 251   251    
Lessee, Operating Lease, Liability, Undiscounted Excess Amount (122)   (122)    
Operating Lease, Liability $ 129   $ 129    
[1] PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power.
[2] PPA capacity payments are included in electric fuel and purchased power on the consolidated statements of income. Expense for other operating leases is included in O&M expense and electric fuel and purchased power.
[3] Includes immaterial short-term lease expense.
[4] Includes immaterial short-term lease expense.