Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 19,534	$ 17,286	$ 17,231
Other comprehensive income (loss)	(4)	51	72
Ending balance	22,748	19,534	17,286
Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(192)	(243)	(315)
Other comprehensive income (loss)	0	54	82
Income tax benefit (expense)	(4)	(3)	(10)
Other comprehensive income (loss)	(4)	51	72
Ending balance	(196)	(192)	(243)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(134)	(177)	(227)
Other comprehensive income (loss)	(16)	43	51
Income tax benefit (expense)	0	0	(1)
Other comprehensive income (loss)	(16)	43	50
Ending balance	(150)	(134)	(177)
Comprehensive income from equity method investment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	1	1	2
Other comprehensive income (loss)	1	0	(1)
Income tax benefit (expense)	0	0	0
Other comprehensive income (loss)	1	0	(1)
Ending balance	2	1	1
Employee benefit plans adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(59)	(67)	(90)
Other comprehensive income (loss)	15	11	32
Income tax benefit (expense)	(4)	(3)	(9)
Other comprehensive income (loss)	11	8	23
Ending balance	$ (48)	$ (59)	$ (67)