Stockholders' Equity - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 3,773	$ 2,708
Other comprehensive income, net of tax	97	(55)
Ending balance	4,092	2,753
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(730)	(726)
Other comprehensive income, net of tax	97	(55)
Ending balance	(633)	(781)
Derivatives Net Unrealized Gains/ (Losses)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(15)	0
Other comprehensive income, net of tax	39	(28)
Ending balance	24	(28)
Net Investment Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(37)	21
Other comprehensive income, net of tax	25	17
Ending balance	(12)	38
Currency Translation Adjustment Net Unrealized Gain/(Losses)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(655)	(724)
Other comprehensive income, net of tax	33	(44)
Ending balance	(622)	(768)
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)