v3.25.4
Retirement Benefits - Schedule of Expected Benefit Payments, Contributions and Expense (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]      
Projected benefit obligation $ 2,360 $ 2,297  
Fair value of plan assets 1,061 1,058  
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]      
Fair value of plan assets 1,061 1,058  
Defined Benefit Pension Plans      
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]      
2026 720    
2027 746    
2028 770    
2029 803    
2030 838    
2031 - 2035 4,711    
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]      
Fair value of plan assets 702 595  
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]      
Accumulated benefit obligation 1,810 1,656  
Fair value of plan assets 702 595  
Components of net periodic (benefit) cost:      
Service cost 324 339 $ 290
Interest cost 697 662 648
Expected return on plan assets (1,086) (1,112) (1,055)
Amortization of prior service (benefit) cost 2 2 2
Recognized actuarial (gain) loss 76 125 122
Net periodic (benefit) cost 13 15 8
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax [Abstract]      
Actuarial gain (loss) arising during period 138 555 (764)
Amortization of net actuarial (gain) loss included in net income 76 125 122
Foreign currency exchange rate changes and other (48) 18 (27)
Total other comprehensive income (loss) during period 166 697 (669)
Retiree Health Benefit Plans      
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]      
2026 95    
2027 96    
2028 96    
2029 97    
2030 97    
2031 - 2035 488    
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]      
Fair value of plan assets 0 0  
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]      
Accumulated benefit obligation 155 142  
Fair value of plan assets 0 0  
Components of net periodic (benefit) cost:      
Service cost 33 35 32
Interest cost 64 62 61
Expected return on plan assets (185) (192) (182)
Amortization of prior service (benefit) cost 0 (6) (53)
Recognized actuarial (gain) loss (4) (3) (6)
Net periodic (benefit) cost (92) (103) (148)
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax [Abstract]      
Actuarial gain (loss) arising during period 65 (37) (50)
Amortization of net actuarial (gain) loss included in net income (4) (3) (6)
Foreign currency exchange rate changes and other 1 (6) (52)
Total other comprehensive income (loss) during period $ 62 $ (46) $ (108)