Property and Equipment - Summarized Category of Fixed Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	$ 6,961	$ 6,806
Less accumulated depreciation and amortization	(3,791)	(3,028)
Total property and equipment, net	3,170	3,778
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	5,623	5,428
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	446	399
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	169	169
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	44	44
Idle Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant & equipment, gross	$ 679	$ 766

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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