Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property and equipment
Property and equipment, gross	$ 29,767	$ 15,314
Less accumulated depreciation and amortization	(12,699)	(11,219)
Property and equipment, net	17,068	4,095
Depreciation and amortization expense	1,500	1,900	$ 1,200
Lab equipment and furniture
Property and equipment
Property and equipment, gross	11,053	8,995
Leasehold improvements
Property and equipment
Property and equipment, gross	14,217	2,731
Software
Property and equipment
Property and equipment, gross	2,225	2,181
Computer equipment
Property and equipment
Property and equipment, gross	1,839	1,313
Construction-in-progress
Property and equipment
Property and equipment, gross	$ 433	$ 94

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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