v3.25.2
Accumulated Other Comprehensive Income (Loss) - After-tax Changes by Component (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Balance at beginning of period $ (184) $ (161) $ (184) $ (163)
Amounts arising during the period (7) 2 (7) 3
Reclassifications from AOCI 1 (1) 1 0
Net OCI during the period (6) 1 (6) 3
Balance at end of period (190) (160) (190) (160)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Balance at beginning of period (3) (4) (3) (4)
Amounts arising during the period 0 0 0 0
Reclassifications from AOCI 0 0 0 0
Net OCI during the period 0 0 0 0
Balance at end of period (3) (4) (3) (4)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Balance at beginning of period (195) (168) (194) (168)
Amounts arising during the period (8) 2 (8) 2
Reclassifications from AOCI 1 (1) 0 (1)
Net OCI during the period (7) 1 (8) 1
Balance at end of period (202) (167) (202) (167)
Equity Investees' OCI        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Balance at beginning of period 4 4 4 3
Amounts arising during the period 0 0 0 1
Reclassifications from AOCI 0 0 0 0
Net OCI during the period 0 0 0 1
Balance at end of period 4 4 4 4
Unrealized gains (losses) on qualifying derivatives [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Balance at beginning of period 10 7 9 6
Amounts arising during the period 1 0 1 0
Reclassifications from AOCI 0 0 1 1
Net OCI during the period 1 0 2 1
Balance at end of period $ 11 $ 7 $ 11 $ 7