Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 34,792	$ 31,697
Less: Accumulated depreciation	(15,014)	(13,587)
Property and equipment, net	19,778	18,110
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	14,505	11,223
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	4,626	4,213
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,138	1,117
Equipment Acquired Under Capital Leases
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,972	4,468
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 10,551	$ 10,676

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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