Fixed Assets, Net - Fixed Assets are Carried at Cost Less Accumulated Depreciation (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Fixed assets, Gross	$ 1,033	$ 801
Less : accumulated depreciation	(724)	(546)
Fixed assets, Net, Total	309	255
Computer Equipment and Capitalized Software [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, Gross	731	704
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, Gross	51	52
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, Gross	209	$ 45
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Fixed assets, Gross	$ 42