Fixed assets (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fixed assets
Gross fixed assets	$ 51,893	$ 33,373
Less accumulated depreciation and amortization	(18,062)	(11,824)
Property, Plant and Equipment, Net, Total	33,831	21,549
Depreciation and amortization	6,600	4,700	$ 2,600
Leasehold improvements
Fixed assets
Gross fixed assets	8,072	5,039
Computer equipment and software
Fixed assets
Gross fixed assets	11,471	8,069
Machinery and lab equipment
Fixed assets
Gross fixed assets	23,430	13,466
Furniture and fixtures
Fixed assets
Gross fixed assets	3,844	3,567
Assets in process
Fixed assets
Gross fixed assets	$ 5,076	$ 3,232

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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