Stockholders' Equity - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 4,092	$ 2,753	$ 3,773	$ 2,708
Other comprehensive income, net of tax	10	(75)	107	(130)
Ending balance	4,352	2,987	4,352	2,987
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(633)	(781)	(730)	(726)
Other comprehensive income, net of tax	10	(75)	107	(130)
Ending balance	(623)	(856)	(623)	(856)
Derivatives Net Unrealized Gains/ (Losses)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(15)	0
Other comprehensive income, net of tax			20	(32)
Ending balance	5	(32)	5	(32)
Net Investment Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(37)	21
Other comprehensive income, net of tax			17	3
Ending balance	(20)	24	(20)	24
Currency Translation Adjustment Net Unrealized Gain/(Losses)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(655)	(724)
Other comprehensive income, net of tax			70	(101)
Ending balance	(585)	(825)	(585)	(825)
Benefit Plans Actuarial Gains/(Losses)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(23)	(23)
Other comprehensive income, net of tax			0	0
Ending balance	$ (23)	$ (23)	$ (23)	$ (23)