Goodwill and Intangible Assets, Net - Summary of Goodwill Activity by Reportable Segments (Details) - USD ($)		3 Months Ended	12 Months Ended
		Jun. 30, 2020	Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Beginning balance			$ 840,000,000		$ 756,000,000
Impairment		$ 0	(3,000,000)	[1]	0	$ 0
Disposition	[2]		(6,000,000)
Acquisitions	[3]				85,000,000
Foreign currency translation adjustments			23,000,000		(1,000,000)
Other adjustments	[4]		8,000,000
Ending balance			862,000,000		840,000,000	756,000,000
Hotel Segment
Goodwill [Line Items]
Beginning balance					451,000,000
Allocation to new segments	[5]				(451,000,000)
Ending balance						451,000,000
Non-Hotel Segment
Goodwill [Line Items]
Beginning balance					305,000,000
Allocation to new segments	[5]				(305,000,000)
Ending balance						$ 305,000,000
Hotels, Media & Platform
Goodwill [Line Items]
Beginning balance			405,000,000
Re-allocation of goodwill	[6]		2,000,000
Allocation to new segments	[5]				405,000,000
Ending balance			407,000,000		405,000,000
Experiences & Dining Segment
Goodwill [Line Items]
Beginning balance			333,000,000
Allocation to new segments	[5]				250,000,000
Acquisitions	[3]				85,000,000
Foreign currency translation adjustments			21,000,000		(2,000,000)
Other adjustments	[4]		8,000,000
Ending balance			362,000,000		333,000,000
Other
Goodwill [Line Items]
Beginning balance	[7]		102,000,000
Re-allocation of goodwill	[6],[7]		(2,000,000)
Impairment	[1],[7]		(3,000,000)
Disposition	[2],[7]		(6,000,000)
Allocation to new segments	[5],[7]				101,000,000
Foreign currency translation adjustments	[7]		2,000,000		1,000,000
Ending balance	[7]		$ 93,000,000		$ 102,000,000

[1] Represents a goodwill impairment charge related to our Tripadvisor China reporting unit.

[2] Disposition relates to the sale of our SmarterTravel business.

[3] These additions to goodwill relate to our business acquisitions. Refer to “Note 3: Acquisitions and Other Investments,” for further information.

[4] Other adjustments primarily relate to an immaterial business acquisition in our Experiences & Dining reportable segment.

[5] Re-allocation of goodwill as a result of changes to our reporting segments during the first quarter of 2019.

[6] Re-allocation of goodwill as a result of changes to reporting units related to internal restructuring during the second quarter of 2020.

[7] Other consists of the combination of Rentals, Flights & Car, and Cruises, and does not constitute a reportable segment.