v3.25.1
Retirement Benefits - Expense (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)    
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Immediate Recognition of Actuarial Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income/(loss), net  
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income/(loss), net  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] Other income/(loss), net  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Other Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income/(loss), net  
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement and Curtailment Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income/(loss), net  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income/(loss), net  
Worldwide OPEB    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)    
Service cost $ 5 $ 6
Interest cost 55 57
Expected return on assets 0 0
Amortization of prior service costs/(credits) 2 2
Net remeasurement (gain)/loss 0 0
Defined Benefit Plan, Other Cost (Credit) 0 0
Settlements and curtailments 0 0
Net periodic benefit cost/(income) 62 65
UNITED STATES | Pension Plan    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)    
Service cost 52 73
Interest cost 393 400
Expected return on assets (456) (455)
Amortization of prior service costs/(credits) 22 23
Net remeasurement (gain)/loss 0 0
Defined Benefit Plan, Other Cost (Credit) 7 8
Settlements and curtailments 0 0
Net periodic benefit cost/(income) 18 49
Foreign Plan | Pension Plan    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)    
Service cost 48 63
Interest cost 224 235
Expected return on assets (278) (255)
Amortization of prior service costs/(credits) 6 6
Net remeasurement (gain)/loss (10) (11)
Defined Benefit Plan, Other Cost (Credit) 24 14
Settlements and curtailments 0 0
Net periodic benefit cost/(income) $ 14 $ 52