Acquisitions - Additional Information (Detail)	12 Months Ended				1 Months Ended		12 Months Ended			12 Months Ended	0 Months Ended	3 Months Ended	12 Months Ended				12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)		Dec. 31, 2012 USD ($)	Nov. 30, 2014 Wotif Group USD ($)	Nov. 30, 2014 Wotif Group AUD	Dec. 31, 2014 Wotif Group USD ($)		Nov. 13, 2014 Wotif Group USD ($)	Dec. 31, 2014 Other Acquisitions USD ($)	Mar. 08, 2013 Trivago USD ($)	Mar. 31, 2014 Trivago	Dec. 31, 2013 Trivago USD ($)		Mar. 08, 2013 Trivago USD ($)	Mar. 08, 2013 Trivago EUR (€)	Dec. 31, 2013 During the first quarter of 2016 Maximum	Dec. 31, 2013 During the first quarter of 2018 Maximum
Business Acquisition [Line Items]
Business acquisition, total cash paid						703,000,000			$ 612,000,000						$ 564,000,000	€ 434,000,000
Business acquisitions, price per share						3.30			$ 2.87
Special dividend distributed						51,000,000
Aggregate purchase consideration					568,000,000	652,000,000	568,000,000			85,000,000			570,000,000
Goodwill	3,955,901,000	3,663,674,000		3,015,670,000			350,093,000			70,000,000			633,436,000
Acquisition-related costs							7,000,000
Business acquisition, cash consideration paid to shareholders										77,000,000	554,000,000
Business acquisition, net assets (liabilities) acquired							(43,429,000)	[1]		(19,000,000)			19,064,000	[2]
Business acquisition, cash acquired										48,000,000
Business acquisition, deferred tax liabilities acquired							2,908,000			17,000,000			111,379,000
Intangible assets with definite lives										51,000,000
Weighted average life of acquired intangible assets							7 years 9 months 18 days			6 years 1 month 6 days			3 years 8 months 12 days
Business acquisitions, equity interest										7,000,000
Business acquisitions, equity interest to fair value gain	2,783,000									2,783,000
Percentage of equity position acquired													63.00%
Percentage of fully diluted basis acquired													61.60%
Business acquisition, cash paid to settle portion of employee compensation plan		9,829,000									9,829,000
Business acquisition, common stock consideration																43,000,000
Business acquisition, common stock consideration, shares											875,200
Business acquisition, fair value of replaced employee stock-based awards of acquiree											15,000,000
Business acquisition, increment of shares issued during the period												175,040
Business acquisition, amount expensed at acquisition		66,472,000	[3]										66,472,000
Stock-based compensation	85,011,000	130,173,000		64,596,000									56,643,000
Percentage of noncontrolling interest													37.00%
Fair value of noncontrolling interest													$ 343,984,000		$ 343,984,000
Minority shareholders right to sell on remaining shares of trivago																	50.00%	100.00%
Revenue related to acquisition as percentage of consolidated revenue													4.00%

[1] Includes cash acquired of $36 million.

[2] Includes cash acquired of $13 million.

[3] Includes stock-based compensation as follows: Cost of revenue $ 3,921 $ 3,752 $ 3,296 Selling and marketing 18,067 16,190 13,474 Technology and content 22,100 20,465 16,073 General and administrative 40,923 33,123 31,753 Acquisition-related and other - 56,643 -