v3.26.1
Accumulated Other Comprehensive Loss - Schedule of AOCI Activity (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Balance at beginning of period     $ (1,117)  
Other comprehensive income before reclassifications     6 $ 3
Amounts reclassified from accumulated other comprehensive loss     31 41
Other comprehensive income $ 17 $ 21 37 44
Balance at end of period (1,488) (595) (1,488) (595)
Total        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Balance at beginning of period (581) (700) (601) (723)
Other comprehensive income 17 21 37 44
Balance at end of period (564) (679) (564) (679)
Defined Benefit Plan | Pension Plans        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Balance at beginning of period     (848) (1,003)
Other comprehensive income before reclassifications     0 0
Amounts reclassified from accumulated other comprehensive loss     48 54
Other comprehensive income     48 54
Balance at end of period (800) (949) (800) (949)
Defined Benefit Plan | Post-Retirement Benefit Plans        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Balance at beginning of period     271 320
Other comprehensive income before reclassifications     0 0
Amounts reclassified from accumulated other comprehensive loss     (17) (13)
Other comprehensive income     (17) (13)
Balance at end of period 254 307 254 307
Foreign Currency Translation Adjustment and Other        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Balance at beginning of period     (24) (40)
Other comprehensive income before reclassifications     6 3
Amounts reclassified from accumulated other comprehensive loss     0 0
Other comprehensive income     6 3
Balance at end of period $ (18) $ (37) $ (18) $ (37)