Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment
Less: accumulated depreciation	$ (8,565)	$ (3,708)
Total property and equipment, net	28,164	19,968
Lab equipment
Property, Plant and Equipment
Property and equipment, gross	18,214	10,771
Office equipment
Property, Plant and Equipment
Property and equipment, gross	2,211	1,610
Furniture and fixtures
Property, Plant and Equipment
Property and equipment, gross	1,301	599
Leasehold improvements
Property, Plant and Equipment
Property and equipment, gross	10,316	2,076
Assets under construction
Property, Plant and Equipment
Property and equipment, gross	$ 4,687	$ 8,620

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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