Property and Equipment, Net - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment gross	$ 15,214	$ 14,573
Less: Accumulated depreciation	(4,524)	(3,384)
Total property and equipment, net	10,690	11,189
Computer and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment gross	1,133	1,124
Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment gross	11,888	11,780
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment gross	604	456
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment gross	805	474
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment gross	350	305
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment gross	$ 434	$ 434

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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