Acquired Intangible Assets Net - Additional Information (Detail) (Shopzilla Customer Contracts, USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended		1 Months Ended
	Dec. 31, 2012	Apr. 30, 2013	Apr. 30, 2013 Cost of revenue	Mar. 01, 2013 Customer Relationships	Dec. 31, 2012 Customer Relationships
Acquired Intangible Assets Amortization [Line Items]
Purchase of customer contracts, purchase price				$ 0.2	$ 4.7
Purchase of customer contracts, cash remitted	4.2
Purchase of customer contracts, holdback liability	0.5
Purchase of customer contracts, remaining useful life of acquired contractual customer relationships					10 years
Amortization expense on acquired intangible assets		$ 5.5	$ 1.6