Accumulated Other Comprehensive Income (Loss) - Summary of AOCI(L) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 3,521	$ 2,358	$ 3,182	$ 3,030
Other comprehensive income (loss)	(48)	72	4	(132)
Ending balance	3,493	2,697	3,493	2,697
Accumulated Other Comprehensive Income Attributable to Parent
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(1,590)	(1,909)	(1,642)	(1,705)
Ending balance	(1,638)	(1,837)	(1,638)	(1,837)
Accumulated Foreign Currency Adjustment Attributable to Parent
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), adjustments during the period	(35)	22	22	(203)
Other comprehensive income (loss), adjustments reclassified to income	0	0	4	0
Income taxes	(24)	41	(55)	43
Other comprehensive income (loss)	(59)	63	(29)	(160)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), adjustments reclassified to income	14	12	41	36
Income taxes	(3)	(3)	(8)	(8)
Other comprehensive income (loss)	$ 11	$ 9	$ 33	$ 28