Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Accounting Policies [Line Items]
Minimum maturity for short term marketable security	90 days
Maximum remaining maturity for short term marketable security	12 months
Maximum maturity period for marketable security	3 years
Weighted Average Maturity	18 months
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%
Goodwill, Impairment Loss	$ 0	$ 0	$ 0
Indefinite-lived intangible assets, Impairment Loss	0	0	0
Foreign exchange losses	10,000,000	0	3,000,000
Advertising expense	341,000,000	237,000,000	175,000,000
Prepaid marketing expenses	5,000,000	1,000,000
Prepaid Expense, Current	5,000,000
Deferred merchant payables	93,000,000	30,000,000
Payable balance acquired with business acquisition	76,000,000
Stock Options
Schedule Of Accounting Policies [Line Items]
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 the assets	3 years
Amortized estimated useful lives of Intangible assets	2 years
Maximum
Schedule Of Accounting Policies [Line Items]
Depreciation over the estimated useful lives of the assets	5 years
Amortized estimated useful lives of Intangible assets	12 years
Expedia | Reclassification of Operating Cash Flow
Schedule Of Accounting Policies [Line Items]
Prior Period Reclassification Adjustment		(8,000,000)	17,000,000
Expedia | Reclassification of Revenue
Schedule Of Accounting Policies [Line Items]
Prior Period Reclassification Adjustment		217,000,000	204,000,000
Expedia | Reclassification of Receivables
Schedule Of Accounting Policies [Line Items]
Prior Period Reclassification Adjustment		$ (16,000,000)
Customer Concentration Risk | Sales | Expedia
Schedule Of Accounting Policies [Line Items]
Customer concentration risk	10.00%	10.00%	10.00%
Customer Concentration Risk | Sales | Expedia and Priceline
Schedule Of Accounting Policies [Line Items]
Customer concentration risk	46.00%	47.00%	48.00%
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	15.00%	14.00%