Property and Equipment - Summarized Category of Fixed Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Right of use, building lease	$ 599	$ 720
Total	7,083	7,688
Less accumulated depreciation and amortization	(5,575)	(5,613)
Total property and equipment, net	1,508	2,075
Machinery & equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	5,203	5,635
Computer equipment & software
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	385	437
Office furniture & equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	174	174
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	43	43
Idle equipment
Property, Plant and Equipment [Line Items]
Property, plant, and equipment, gross	$ 679	$ 679