Fixed Assets, net - Schedule of Fixed Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Less accumulated depreciation and amortization	$ (7,410)	$ (6,304)
Total	8,127	9,122
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	2,330	2,244
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	2,218	2,218
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 10,989	$ 10,964