v3.20.1
Post-Employment Benefits (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Defined benefit plans    
Defined benefit and other post-employment plans    
Service cost $ 92 $ 67
Interest cost 61 64
Expected return on plan assets (135) (119)
Amortization of actuarial losses and prior service cost (credit) 55 26
Net periodic benefit cost 73 38
Other post-employment plans    
Defined benefit and other post-employment plans    
Service cost 12 6
Interest cost 9 6
Expected return on plan assets 0 0
Amortization of actuarial losses and prior service cost (credit) 6 (1)
Net periodic benefit cost $ 27 $ 11