Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 55,292	$ 53,377
Less: accumulated depreciation and amortization	(22,595)	(16,375)
Property and equipment, net	32,697	37,002
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment, at cost	14,017	12,703
Manufacturing Equipment
Property Plant And Equipment [Line Items]
Property and equipment, at cost	7,959	7,754
Computers and Purchased Software
Property Plant And Equipment [Line Items]
Property and equipment, at cost	1,597	1,596
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, at cost	1,625	1,363
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, at cost	30,074	29,961
Assets Not Yet in Service
Property Plant And Equipment [Line Items]
Property and equipment, at cost	$ 20