Property and Equipment (Property and Equipment) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Leasehold Improvements, Gross	$ 321	$ 153
Machinery and Equipment, Gross	1,393	0
Computer and office equipment	10,141	8,995
Furniture and Fixtures, Gross	137	60
Capital Leased Assets, Gross	6,700	0
Property, Plant and Equipment, Gross	18,692	9,208
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(11,474)	(9,170)
Construction in Progress, Gross	4	0
Property, Plant and Equipment, Net	$ 7,222	$ 38