Goodwill - Summary of Changes in Goodwill by Reportable Segment (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Goodwill [Line Items]
Beginning balance	$ 756
Other adjustments	(2)	[1]
Ending balance	754
Hotel Segment
Goodwill [Line Items]
Beginning balance	451
Allocation to new segments	(451)	[2]
Non-Hotel Segment
Goodwill [Line Items]
Beginning balance	305
Allocation to new segments	(305)	[2]
Hotels, Media & Platform
Goodwill [Line Items]
Allocation to new segments	405	[2]
Ending balance	405
Experiences & Dining Segment
Goodwill [Line Items]
Allocation to new segments	250	[2]
Other adjustments	(2)	[1]
Ending balance	248
Other Segments
Goodwill [Line Items]
Allocation to new segments	101	[2],[3]
Ending balance	$ 101	[3]

[1] Primarily related to impact of changes in foreign currency exchange rates to goodwill.

[2] Refer to “Note 15: Segment Information” for information on our reporting segment changes in the first quarter of 2019.

[3] Other consists of the combination of our Rentals, Flights/Cruises/Car Rentals, SmarterTravel, and TripAdvisor China business units and does not constitute a reportable segment.