v3.25.4
Employee Benefits - Change In Benefit Obligations Change In Plan Assets Funded Status (Detail) - USD ($)
$ in Millions
 12 Months Ended
Mar. 06, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension        
Change in Benefit Obligations        
Beginning of year   $ 7,918 $ 15,133  
Service cost   160 185 $ 208
Interest cost   405 479 752
Plan amendments   0 0  
Actuarial (gain) loss, net   137 (1,130)  
Benefits paid   (435) (419)  
Curtailment and termination benefits   1 6  
Settlements paid   (215) (725)  
Annuity contracts transfer   0 (5,611)  
End of year   7,971 7,918 15,133
Change in Plan Assets        
Beginning of year   6,802 13,536  
Actual return on plan assets   456 (400)  
Company contributions   1,313 421  
Benefits paid   (435) (419)  
Settlements paid   (215) (725)  
Annuity contracts transfer $ 5,600 0 (5,611)  
End of year   7,921 6,802 13,536
Funded Status        
Funded Status - End of year   (50) (1,116)  
Health Care and Life        
Change in Benefit Obligations        
Beginning of year   10,539 11,455  
Service cost   33 52 54
Interest cost   547 543 545
Plan amendments   1 0  
Actuarial (gain) loss, net   279 (533)  
Benefits paid   (801) (978)  
Curtailment and termination benefits   0 0  
Settlements paid   0 0  
Annuity contracts transfer   0 0  
End of year   10,598 10,539 11,455
Change in Plan Assets        
Beginning of year   466 466  
Actual return on plan assets   71 43  
Company contributions   762 935  
Benefits paid   (801) (978)  
Settlements paid   0 0  
Annuity contracts transfer   0 0  
End of year   498 466 $ 466
Funded Status        
Funded Status - End of year   $ (10,100) $ (10,073)