v3.25.2
Changes in Accumulated Other Comprehensive Income - Schedule of Changes in AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Jun. 30, 2025
Jun. 30, 2024
Movement in Accumulated Other Comprehensive Income [Roll Forward]            
Beginning balance $ 27,607 $ 26,921 $ 26,061 $ 25,755 $ 26,921 $ 25,755
Other comprehensive income, net of income taxes 0 2 0 14 2 14
Ending balance 27,620 27,607 26,152 26,061 27,620 26,152
Pension and Non-Pension Postretirement Benefit Plan Items            
Movement in Accumulated Other Comprehensive Income [Roll Forward]            
Beginning balance (755) (765) (742) (723) (765) (723)
OCI before reclassifications 1   (2)   5 (26)
Amounts reclassified from AOCI 5   5   11 10
Other comprehensive income, net of income taxes 6   3   16 (16)
Ending balance (749) (755) (739) (742) (749) (739)
Total            
Movement in Accumulated Other Comprehensive Income [Roll Forward]            
Beginning balance (718) (720) (712) (726) (720) (726)
OCI before reclassifications (3)   (4)   (6) 6
Amounts reclassified from AOCI 3   4   8 8
Other comprehensive income, net of income taxes 0 2 0 14 2 14
Ending balance (718) (718) (712) (712) (718) (712)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent            
Movement in Accumulated Other Comprehensive Income [Roll Forward]            
Beginning balance 37 45 30 (3) 45 (3)
OCI before reclassifications (4)   (2)   (11) 32
Amounts reclassified from AOCI (2)   (1)   (3) (2)
Other comprehensive income, net of income taxes (6)   (3)   (14) 30
Ending balance $ 31 $ 37 $ 27 $ 30 $ 31 $ 27