Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment	$ 61,138	$ 61,111
Less accumulated depreciation and amortization	(27,102)	(26,534)
Property and equipment, net	$ 34,036	34,577
Property and equipment, estimated useful life	1 year
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 29,220	34,040
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	7 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 10,550	9,349
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	2 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	5 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 4,315	4,398
Property and equipment, estimated useful life	7 years
Computer Hardware and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 8,268	5,175
Property and equipment, estimated useful life	3 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 5,346	7,717
Computer Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	2 years
Computer Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Assets Not Yet Placed in Service [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 3,439	$ 432