Leases - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Apr. 05, 2021	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases
Lease liability			$ 13,550
Letter of credit for security deposit			478	$ 321
Increase in ROU asset		$ 3,783
Right-of-use assets obtained in exchange for financing lease liabilities			609	0	$ 429
Rent expense			$ 3,390	$ 2,644	$ 2,160
Operating lease liabilities		$ 3,783
Minimum
Leases
Finance lease, remaining lease term			1 year
Maximum
Leases
Finance lease, remaining lease term			5 years
Office space, Cambridge, MA, Leased
Leases
Renewal term			5 years
Office Space Expansion Cambridge Ma
Leases
Renewal term	5 years
Operating lease term of contract	5 years
Lease liability	$ 4,983
Letter of credit for security deposit	157
Tenant improvement allowance	$ 51