Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 20,837	$ 19,647
Accumulated depreciation	(14,201)	(13,466)
Property and equipment, net	6,636	6,181
Land and Office Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	7,515	7,069
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	6,509	6,227
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	6,739	6,277
Automobiles [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 74	$ 74