Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total property and equipment	$ 13,844	$ 13,152
Less: accumulated depreciation	(5,449)	(3,947)
Property and equipment, net	8,395	9,205
Lab Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	6,468	5,710
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	594	548
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	373	512
Software
Property Plant And Equipment [Line Items]
Total property and equipment	199	90
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 6,210	6,210
Construction in Process
Property Plant And Equipment [Line Items]
Total property and equipment		$ 82