Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 31,864	$ 25,673
Less: accumulated depreciation and amortization	(13,868)	(8,612)
Property and equipment, net	17,996	17,061
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	27,199	22,453
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	1,121	960
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	1,051	929
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	1,474	898
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 1,019	$ 433