Leases - Other (Details) $ in Thousands		1 Months Ended		12 Months Ended
	Apr. 18, 2019 ft²	Oct. 31, 2017	Jun. 30, 2016 ft² period	Dec. 31, 2019 USD ($) period
Leases
Options to renew				true
Additional right of use asset and related lease liability				$ 2,044
Operating lease asset				6,655
Operating lease liability				$ 10,031
Minimum
Leases
Lease term				1 year
Renewal terms				1 year
Additional periods for renewal | period				1
Maximum
Leases
Lease term				8 years
Renewal terms				6 years
Office space lease, Bedford, Massachusetts
Leases
Lease term	5 years
Options to renew	false
Area covered under lease | ft²	30,036
Lease Agreement, June 2016, Bedford, Massachusetts
Leases
Options to renew			true
Renewal terms			5 years
Additional periods for renewal | period			2
Area covered under lease | ft²			70,712
Lease Agreement, June 2016, Bedford, Massachusetts | Minimum
Leases
Written notice period to extend the lease			12 months
Lease Agreement, June 2016, Bedford, Massachusetts | Maximum
Leases
Written notice period to extend the lease			15 months
Laboratory and manufacturing space lease
Leases
Option to terminate		true