Equipment and Improvements - Summary of Equipment and Improvements (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Gross, Total	$ 14,725	$ 13,511
Less accumulated depreciation and amortization	(12,027)	(11,341)
Equipment and improvements, net	2,698	2,170
Computer Hardware, Software, and Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross, Total	10,531	9,814
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Gross, Total	3,378	2,959
Office Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Gross, Total	803	714
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Gross, Total	$ 13	$ 24