Significant Accounting Policies - Additional Information (Details)		1 Months Ended	3 Months Ended	12 Months Ended
		Jun. 30, 2013 ft²	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) ft² Subsidiary ReportingUnit Location	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2019 USD ($)
Schedule Of Accounting Policies [Line Items]
Advertising expense				$ 423,000,000	$ 544,000,000	$ 629,000,000
Prepaid advertising expenses				$ 2,000,000	$ 2,000,000
Expected dividend yield				0.00%
Financial instruments including money market funds maturities period				90 days	90 days
Minimum maturities of short-term marketable securities				90 days	90 days
Maximum remaining maturity for short-term marketable securities				12 months	12 months
Maximum maturity period for marketable security				3 years
Weighted Average Maturity				18 months
Customer invoices due period				30 days
Minimum maturity at purchase date for a short term marketable security				90 days
Minimum probability that the fair value of the reporting unit is less than the carrying amount				50.00%
Number of distinct reporting units | ReportingUnit				4
Goodwill impairment loss			$ 0	$ 0	$ 0	0
Carrying value of indefinite-lived intangible assets				30,000,000	30,000,000
Deferred merchant payables				159,000,000	164,000,000
Net foreign currency exchange gains/(losses)	[1]			$ (2,000,000)	(9,000,000)	$ 1,000,000
Foreign currency exchange contracts maturity period, maximum				90 days
Operating lease right-of-use assets				$ 74,000,000
Operating lease liabilities				84,000,000
Leased area | ft²		280,000
Finance lease liability				83,000,000
ROU asset, net of accumulated amortization	[2]			9,000,000
Accumulated amortization				$ 319,000,000	$ 240,000,000
Corporate HQ Building
Schedule Of Accounting Policies [Line Items]
Lease expiration date		Dec. 01, 2030
Initial term of lease		15 years 7 months
Extended lease term		5 years
Accounting Standards Update 2016-02
Schedule Of Accounting Policies [Line Items]
Operating lease right-of-use assets	[3]						$ 75,000,000
Operating lease liabilities							88,000,000
Operating lease, term				6 years
Operating lease, existence of option to extend				true
Operating lease, existence of option to terminate				true
Operating lease, Option to terminate				within 1 year
Finance lease ROU assets							114,000,000
Finance lease liability							88,000,000
Finance lease prepaid rent							26,000,000
Accounting Standards Update 2016-02 | Property and Equipment, Net
Schedule Of Accounting Policies [Line Items]
ROU asset, net of accumulated amortization				$ 105,000,000
Accounting Standards Update 2016-02 | Corporate Headquarters Lease
Schedule Of Accounting Policies [Line Items]
Net asset							26,000,000
Accumulated amortization				$ 9,000,000
Accounting Standards Update 2016-02 | Difference between Leases Guidance in Effect before and after Topic 842
Schedule Of Accounting Policies [Line Items]
Operating lease right-of-use assets							88,000,000
Deferred rent							$ (13,000,000)
Customer Concentration Risk | Sales | Expedia
Schedule Of Accounting Policies [Line Items]
Customer concentration risk				10.00%	10.00%	10.00%
Customer Concentration Risk | Sales | Booking
Schedule Of Accounting Policies [Line Items]
Customer concentration risk				10.00%	10.00%	10.00%
Customer Concentration Risk | Sales | Expedia and Booking
Schedule Of Accounting Policies [Line Items]
Customer concentration risk				33.00%	37.00%	43.00%
Trademarks and Tradenames
Schedule Of Accounting Policies [Line Items]
Carrying value of indefinite-lived intangible assets				$ 30,000,000
Impairment of indefinite-lived intangible assets				$ 0
Minimum
Schedule Of Accounting Policies [Line Items]
Depreciation over the estimated useful lives of assets				3 years
Maximum
Schedule Of Accounting Policies [Line Items]
Depreciation over the estimated useful lives of assets				5 years
Maximum | Accounting Standards Update 2016-02
Schedule Of Accounting Policies [Line Items]
Lease expiration date				Jun. 30, 2027
Stock Options
Schedule Of Accounting Policies [Line Items]
Term of stock options, granted				10 years
Stock options vest period				4 years
Restricted Stock Units
Schedule Of Accounting Policies [Line Items]
Stock options vest period				4 years
China
Schedule Of Accounting Policies [Line Items]
Number of operating subsidiaries | Subsidiary				1
North America and Europe and Asia Pacific
Schedule Of Accounting Policies [Line Items]
Leased area of office space | ft²				505,000
Leased location | Location				50
Lease expiration date				Jun. 30, 2027

[1] Our foreign currency exchange gains (losses), net, are generally related to foreign exchange transaction gains and losses from the conversion of the transaction currency to the functional currency, partially offset by the foreign currency forward contract gains and losses.

[2] Amount is included in depreciation expense in our consolidated statement of operations. During both the years ended December 31, 2018 and 2017, we recorded depreciation expense of $3 million related to our Headquarters Lease in our consolidated statement of operations in accordance with ASC 840.

[3] Refer to the below discussion regarding the transition accounting for operating and finance leases upon adoption of ASC 842.