Segment Information - Summary of Segment Information (Parenthetical) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
General and administrative	[1]	$ 51	$ 40	$ 138	$ 129
Reportable Segments | Hotels, Media & Platform
Segment Reporting Information [Line Items]
General and administrative		20	18	51	57
Advertising expense		$ 18	$ 37	$ 73	$ 98

[1] Includes stock-based compensation expense as follows