Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 01, 2016
Schedule Of Accounting Policies [Line Items]
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
Cost method investments	$ 14	$ 0
Minimum maturity at purchase date for a short term marketable security	90 days
Accounts receivable due period	30 days
Minimum probability that the fair value of the reporting unit is less than the carrying amount	50.00%
Foreign currency exchange losses	$ 4	4	$ 10
Advertising expense	543	507	341
Prepaid marketing expenses	5	2
Prepaid Expense, Current	5
Deferred merchant payables	$ 128	105
Foreign currency exchange contracts maturity period, maximum	90 days
Increase in cash flows from operating activities	$ 321	418	407
Reduction in cash flows from financing activities	143	189	61
New Accounting Pronouncement, Early Adoption | ASU 2016-09
Schedule Of Accounting Policies [Line Items]
Increase in cash flows from operating activities		36	20
Reduction in cash flows from financing activities		$ 36	$ 20
Reduction to retained earnings				$ 1
Recognition of net excess tax expense (benefit) in provision for income taxes	$ 1
Customer Concentration Risk | Sales | Expedia and Priceline
Schedule Of Accounting Policies [Line Items]
Customer concentration risk	46.00%	46.00%	46.00%
Customer Concentration Risk | Sales | Expedia
Schedule Of Accounting Policies [Line Items]
Customer concentration risk	10.00%	10.00%	10.00%
Customer Concentration Risk | Sales | Priceline
Schedule Of Accounting Policies [Line Items]
Customer concentration risk	10.00%	10.00%	10.00%
Credit Concentration Risk | Accounts Receivable | Expedia
Schedule Of Accounting Policies [Line Items]
Customer concentration risk	12.00%	11.00%
Stock Options
Schedule Of Accounting Policies [Line Items]
Term of stock options, granted	10 years
Stock options requisite service period	4 years
Stock options vest period	4 years
Restricted Stock Units
Schedule Of Accounting Policies [Line Items]
Stock options vest period	4 years
Minimum
Schedule Of Accounting Policies [Line Items]
Depreciation over the estimated useful lives of assets	3 years
Amortized estimated useful lives of Intangible assets	1 year
Maximum
Schedule Of Accounting Policies [Line Items]
Depreciation over the estimated useful lives of assets	5 years
Amortized estimated useful lives of Intangible assets	12 years