Acquired Intangible Assets Net (Detail) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	$ 57,227
Accumulated Amortization	(3,762)
Net Book Value	53,465
Domain Name
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	800
Net Book Value	800
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	51,027
Accumulated Amortization	(2,622)
Net Book Value	48,405
Developed Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	5,400
Accumulated Amortization	(1,140)
Net Book Value	$ 4,260