Summary of Fair Value of Assets Acquired and Liabilities Assumed in Conjunction with Acquisition (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Mar. 08, 2013 Trivago
Business Acquisition [Line Items]
Goodwill	$ 3,643,196	$ 3,015,670	$ 635,565
Intangible assets with indefinite lives			220,416
Intangible assets with definite lives			136,281	[1]
Net assets			16,935	[2]
Deferred tax liabilities			(111,379)
Redeemable noncontrolling interest			(343,984)
Total			$ 553,834

[1] Acquired definite-lived intangible assets primarily consist of technology, partner relationship and non-compete agreement assets and have estimated useful lives of between 3 and 7 years with a weighted average life of 3.7 years.

[2] Includes cash acquired of $13 million.