Acquired Intangible Assets Net - Additional Information (Detail) (Shopzilla Customer Contracts, USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended	9 Months Ended
	Dec. 31, 2012	Jan. 31, 2013	Jan. 31, 2013
Acquired Intangible Assets Amortization [Line Items]
Purchase of customer contracts, cash remitted	$ 4.2
Purchase of customer contracts, holdback liability	0.5
Amortization expense on acquired intangible assets		1.7	3.7
Cost of revenue
Acquired Intangible Assets Amortization [Line Items]
Amortization expense on acquired intangible assets		0.5	1.2
Customer Relationships
Acquired Intangible Assets Amortization [Line Items]
Purchase of customer contracts, purchase price	$ 4.7
Purchase of customer contracts, remaining useful life of acquired contractual customer relationships	10 years