Goodwill and Intangible Assets, Net - Components of Intangible Assets with Definite Lives (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Cost	$ 2,584	$ 2,462
Accumulated Amortization	(2,064)	(1,870)
Net	520	592
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	658	659
Accumulated Amortization	(499)	(419)
Net	159	240
Supplier relationships
Finite-Lived Intangible Assets [Line Items]
Cost	651	650
Accumulated Amortization	(483)	(426)
Net	168	224
Domain names
Finite-Lived Intangible Assets [Line Items]
Cost	183	159
Accumulated Amortization	(109)	(83)
Net	74	76
Technology
Finite-Lived Intangible Assets [Line Items]
Cost	529	544
Accumulated Amortization	(521)	(510)
Net	8	34
Other(1)
Finite-Lived Intangible Assets [Line Items]
Cost	563	450
Accumulated Amortization	(452)	(432)
Net	$ 111	$ 18