Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 17,084	$ 15,517
Less accumulated depreciation	(9,477)	(7,595)
Net property and equipment	7,607	7,922
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,270	8,150
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,086	1,999
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,728	$ 5,368