Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 47,237	$ 46,595
Less: Accumulated depreciation and amortization	(27,742)	(20,301)
Property and equipment, net	19,495	26,294
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	15,140	14,695
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,874	2,864
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,033	1,033
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	27,977	27,977
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 213	$ 26

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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