Property and Equipment - 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	$ 19,617	$ 19,757
Less: Accumulated depreciation	(15,404)	(14,616)
Property and equipment, net	4,213	5,141
Furniture and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	15,583	12,878
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,844	6,451
Capitalized Leases
Property, Plant and Equipment [Line Items]
Property and equipment, gross		238
Aircraft
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 190	$ 190