Commitments and Contingencies (Details) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Feb. 28, 2018 USD ($) item	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2015
Lease Cost:
Operating lease cost		$ 344	$ 687
Variable lease cost		210	377
Total lease cost		$ 554	1,064
Operating cash flows used for operating leases			$ 706
Weighted average remaining lease term		3 years 3 months	3 years 3 months
Weighted average incremental borrowing rate		6.47%	6.47%
620 Memorial Drive, Cambridge MA
Leased assets
Term of lease				5 years
Option to extend the term	true
Number of renewal options | item	1
Renewal term	5 years
620 Memorial Drive, Cambridge MA | Minimum
Leased assets
Rent for facility lease	$ 1,400
620 Memorial Drive, Cambridge MA | Maximum
Leased assets
Rent for facility lease	$ 1,700