Post-Employment Benefits - Benefit Plan Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amounts recognized on the consolidated balance sheets
Other long-term liabilities	$ (3,153)	$ (3,413)
Defined benefit plans
Projected benefit obligations
Beginning of period	11,792	8,646
Service cost	440	370	$ 269
Interest cost	237	264	259
Employee contributions	2	2
Amendments	0	0
Actuarial (gain) loss	(8)	1,105
Benefits paid	(281)	(249)
Acquisition	0	1,409
Other, primarily foreign currency translation adjustments	(176)	245
End of period	12,006	11,792	8,646
Fair value of plan assets
Beginning of period	9,702	7,116
Actual return on plan assets	1,000	979
Company contributions	376	367
Employee contributions	2	2
Benefits paid	(281)	(249)
Acquisition	0	1,296
Other, primarily foreign currency translation adjustments	(144)	191
End of period	10,655	9,702	7,116
Funded status, end of period	(1,351)	(2,090)
Amounts recognized on the consolidated balance sheets
Other assets	991	563
Accounts payable and accrued liabilities	(13)	(12)
Other long-term liabilities	(2,329)	(2,641)
Net obligation	(1,351)	(2,090)
Actuarial loss, net	(3,504)	(4,163)
Prior service cost (credit)	5	8
Accumulated other comprehensive loss	3,509	4,171
Other post-employment plans
Projected benefit obligations
Beginning of period	795	1,050
Service cost	48	42	25
Interest cost	19	34	29
Amendments		(397)
Actuarial (gain) loss	10	40
Benefits paid	(22)	(17)
Acquisition	0	43
Other, primarily foreign currency translation adjustments	0	0
End of period	850	795	$ 1,050
Fair value of plan assets
Company contributions	22	17
Benefits paid	(22)	(17)
Acquisition	0	0
Funded status, end of period	(850)	(795)
Amounts recognized on the consolidated balance sheets
Accounts payable and accrued liabilities	(26)	(23)
Other long-term liabilities	(824)	(772)
Net obligation	(850)	(795)
Actuarial loss, net	(461)	(482)
Prior service cost (credit)	(370)	(408)
Accumulated other comprehensive loss	$ 91	$ 74