Postretirement Benefit Plans (Summary of Amounts Recognized in Financial Statements) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in benefit obligation:
Benefit obligation at beginning of year	$ 1,199
Benefit obligation at end of year	1,085	$ 1,199
Change in plan assets:
Beginning Balance	691
Ending Balance	679	691
Unfunded status of the plans	(406)	(508)
United States
Change in benefit obligation:
Benefit obligation at beginning of year	123	113
Service cost	3	3	$ 3
Interest cost	3	3	4
Benefits paid	(7)	(6)
Actuarial loss (gain)	(5)	10
Plan amendments, settlements and curtailments	0	0
Foreign currency translation/other	0	0
Benefit obligation at end of year	117	123	113
Change in plan assets:
Beginning Balance	113	105
Employer contributions	0	0
Actual return on plan assets	2	14
Benefits paid	(7)	(6)
Plan amendments, settlements and curtailments	0	0
Foreign currency translation/other	0	0
Ending Balance	108	113	105
Unfunded status of the plans	(9)	(10)
International defined benefit pension plans
Change in benefit obligation:
Benefit obligation at beginning of year	1,032	846
Service cost	14	13	9
Interest cost	11	16	19
Benefits paid	(34)	(34)
Actuarial loss (gain)	(56)	130
Plan amendments, settlements and curtailments	(3)	(1)
Foreign currency translation/other	(38)	62
Benefit obligation at end of year	926	1,032	846
Change in plan assets:
Beginning Balance	578	500
Employer contributions	26	24
Actual return on plan assets	9	70
Benefits paid	(34)	(34)
Plan amendments, settlements and curtailments	(3)	(1)
Foreign currency translation/other	(5)	19
Ending Balance	571	578	$ 500
Unfunded status of the plans	$ (355)	$ (454)