Equipment, Furniture and Leasehold Improvements - Equipment, Furniture and Leasehold Improvements (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total	$ 4,478	$ 4,169
Less: accumulated depreciation and amortization	(3,389)	(3,002)
Equipment, furniture and leasehold improvements, net	1,089	1,167
Computer equipment and software [Member]
Property, Plant and Equipment [Line Items]
Total	2,929	2,667
Office furniture and equipment [Member]
Property, Plant and Equipment [Line Items]
Total	357	305
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total	$ 1,192	$ 1,197