Segment Information - Summary of Segment Information (Parenthetical) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
General and administrative	[1]	$ 45	$ 46	$ 88	$ 88
Reportable Segments | Hotels, Media & Platform
Segment Reporting Information [Line Items]
General and administrative		17	19	31	39
Advertising expense		$ 26	$ 35	$ 55	$ 61

[1] Includes stock-based compensation expense as follows