Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 12,732	$ 11,503
Less: accumulated depreciation	(5,211)	(3,599)
Property and equipment, net	7,521	7,904
Depreciation expense	1,600	1,200	$ 900
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,637	1,401
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,737	1,442
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,938	2,938
Laboratory and production equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,000	654
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 420	$ 5,068

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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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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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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