Balance Sheet Components - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 57,125	$ 49,946
Less: Accumulated depreciation and amortization	(36,544)	(28,129)
Property and equipment, net	20,581	21,817
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	28,905	26,279
Software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	21,323	16,602
Office Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	951	1,016
Furniture, Fixtures and Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 5,946	$ 6,049