Property and Equipment, net - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 49,091	$ 42,534
Less accumulated depreciation and amortization	(36,344)	(29,548)
Property and equipment, net	12,747	12,986
Computers, equipment and software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	37,249	33,706
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,546	5,214
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,630	2,559
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,666	$ 1,055