Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 85,704	$ 82,603
Less: accumulated depreciation and amortization	51,303	46,306
Property and equipment, net	34,401	36,297
Land [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	9,927	9,942
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	15,558	15,512
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	39,425	37,361
Office Furniture Equipment and Other [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	8,736	8,029
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	9,377	9,014
Right-of-Use Assets Under Finance Leases [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2,681	$ 2,745