Property and Equipment - Components of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 16,088	$ 15,163
Less: Accumulated depreciation	(12,915)	(11,651)
Property and equipment, net	3,173	3,512
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,660	9,736
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,000	4,999
Capitalized Leases [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	238	238
Aircraft [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 190	$ 190