Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 77,346	$ 70,580
Less: accumulated depreciation and amortization	43,296	40,427
Property and equipment, net	34,050	30,153
Land [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	7,994	7,994
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	13,379	13,120
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	36,354	34,582
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	8,512	7,958
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	8,500	$ 6,926
Right-of-Use Assets Under Finance Leases [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2,607