Balance Sheet Components - Components of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 35,331	$ 26,436
Less: Accumulated depreciation and amortization	(19,057)	(12,019)
Property and equipment, net	16,274	14,417
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	21,422	16,314
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,022	7,690
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	795	571
Furniture, Fixtures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,092	$ 1,861