Goodwill and Intangible Assets, Net - Components of Intangible Assets with Definite Lives (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	4 years 4 months 24 days
Gross Carrying Amount	$ 253	$ 228
Accumulated Amortization	(173)	(140)
Intangible assets with definite lives, net	$ 80	88
Trade Names and Trademarks
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	4 years 6 months
Gross Carrying Amount	$ 59	57
Accumulated Amortization	(35)	(28)
Intangible assets with definite lives, net	$ 24	29
Customer Lists and Supplier Relationships
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	4 years 4 months 24 days
Gross Carrying Amount	$ 98	88
Accumulated Amortization	(65)	(53)
Intangible assets with definite lives, net	$ 33	35
Subscriber Relationships
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	3 years 3 months 18 days
Gross Carrying Amount	$ 40	34
Accumulated Amortization	(29)	(25)
Intangible assets with definite lives, net	$ 11	9
Technology and Other
Finite Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	5 years 1 month 6 days
Gross Carrying Amount	$ 56	49
Accumulated Amortization	(44)	(34)
Intangible assets with definite lives, net	$ 12	$ 15