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 current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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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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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services 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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Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property and equipment
Property and equipment, gross	$ 31,907		$ 31,907		$ 29,767
Less accumulated depreciation and amortization	(14,512)		(14,512)		(12,699)
Property and equipment, net	17,395		17,395		17,068
Depreciation and amortization expense	700	$ 400	1,800	$ 1,100
Lab equipment and furniture
Property and equipment
Property and equipment, gross	12,374		12,374		11,053
Leasehold improvements
Property and equipment
Property and equipment, gross	15,185		15,185		14,217
Software
Property and equipment
Property and equipment, gross	2,225		2,225		2,225
Computer equipment
Property and equipment
Property and equipment, gross	2,089		2,089		1,839
Construction-in-progress
Property and equipment
Property and equipment, gross	$ 34		$ 34		$ 433