Leases - Summary of Lease Costs (Details) - Watertown Lease - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Lease cost:
Operating lease cost	$ 2,686	$ 2,550	$ 2,550
Variable lease cost	857	1,066	1,020
Total lease cost	$ 3,543	$ 3,616	$ 3,570