Consolidated Balance Sheet Components - Property and Equipment, Net (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 16,852	$ 13,165
Less: accumulated depreciation and amortization	(9,234)	(7,690)
Total property and equipment, net	7,618	5,475
Computers and related equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	11,591	8,989
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	1,510	1,403
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 3,751	$ 2,773