Balance Sheet Components - Property and Equipment - Tabular Disclosure (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 27,335	$ 26,957
Accumulated depreciation and amortization	(19,537)	(18,844)
Property and equipment, net	7,798	8,113
Machinery and Equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	17,057	17,522
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	4,444	4,445
Software and Software Development Costs [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	4,791	4,142
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	744	733
Construction in Progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 299	$ 115

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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