Acquisitions - Additional Information (Detail)	6 Months Ended		0 Months Ended	3 Months Ended				3 Months Ended
	Jun. 30, 2013 USD ($)		Mar. 08, 2013 Trivago USD ($)	Mar. 31, 2014 Trivago	Mar. 31, 2013 Trivago USD ($)	Mar. 08, 2013 Trivago USD ($)	Mar. 08, 2013 Trivago EUR (€)	Mar. 31, 2018 Trivago Scenario Forecast Maximum	Mar. 31, 2016 Trivago Scenario Forecast Maximum	Jul. 31, 2014 Wotif.com Holdings Limited Subsequent Event AUD	Jul. 04, 2014 Wotif.com Holdings Limited Subsequent Event USD ($)
Business Acquisition [Line Items]
Business acquisition, expected purchase price										703,000,000	$ 658,000,000
Business acquisitions, price per share										3.30	$ 3.09
Percentage of equity position acquired					63.00%
Percentage of fully diluted basis acquired					61.60%
Business acquisition, total cash paid						564,000,000	434,000,000
Business acquisition, cash consideration paid to shareholders			554,000,000
Business acquisition, cash paid to settle portion of employee compensation plan	9,829,000		9,829,000
Business acquisition, common stock consideration, shares			875,200
Business acquisition, amount expensed at acquisition	66,472,000	[1]			66,472,000
Stock-based compensation					$ 56,643,000
Business acquisition, increment of shares issued during the period				175,040
Minority shareholders right to sell on remaining shares of trivago								100.00%	50.00%

[1] Includes stock-based compensation as follows: Cost of revenue $ 943 $ 764 $ 2,145 $ 1,825 Selling and marketing 4,820 3,649 10,155 7,914 Technology and content 4,960 4,692 10,518 10,087 General and administrative 10,291 6,981 23,017 14,695 Acquisition-related and other - - - 56,643