Employee Benefits - Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension Benefits
Net Periodic Benefit Cost
Net Periodic Other Benefit Costs	$ 190	$ 478
Pension Benefits | United States
Net Periodic Benefit Cost
Service cost	118	117
Interest cost	66	55
Expected return on plan assets	(161)	(149)
Amortization of prior service costs (credits)	0	1
Amortization of actuarial losses (gains)	65	104
Settlement losses	86	317
Net Periodic Other Benefit Costs	174	445
Pension Benefits | International
Net Periodic Benefit Cost
Service cost	22	34
Interest cost	36	33
Expected return on plan assets	(48)	(46)
Amortization of prior service costs (credits)	2	2
Amortization of actuarial losses (gains)	4	10
Settlement losses	0	0
Net Periodic Other Benefit Costs	16	33
Other Benefits
Net Periodic Benefit Cost
Service cost	11	11
Interest cost	15	13
Amortization of prior service costs (credits)	(6)	(7)
Amortization of actuarial losses (gains)	3	4
Net Periodic Other Benefit Costs	$ 23	$ 21