Property and Equipment - Summarized Category of Fixed Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	$ 6,681	$ 6,276
Less accumulated depreciation	(2,451)	(2,014)
Total property, plant & equipment, net	4,230	4,262
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	4,476	580
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	464	460
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	202	200
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	53	53
Idle Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	$ 1,486	$ 4,983