Leases (Details) $ in Thousands				12 Months Ended
	Sep. 01, 2020 USD ($) ft²	Nov. 11, 2019 USD ($) ft²	Mar. 13, 2019 USD ($) ft²	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Right-of-use assets				$ 7,229	$ 8,710
Lessee, Operating Lease, Security Deposit, Line Of Credit				900
Operating lease, liability				4,801
Lease liabilities				3,603	4,776
Current portion of lease liability				1,198	1,075
Right-of-use asset, amortization term			5 years
Fixed operating lease cost				2,080	2,087	$ 1,290
Short-term lease costs				0	42	157
Total lease expense				2,080	2,129	1,447
Operating cash flows from operating leases				1,354	1,257	3,820
Leased assets obtained in exchange for new operating lease liabilities				$ 0	$ 1,343	$ 5,090
Weighted-average remaining lease term—operating leases				4 years	5 years	5 years 6 months
Weighted-average discount rate—operating leases				11.40%	11.30%	11.20%
Sublease income				$ 196	$ 196	$ 194
Waltham Lease
Lessee, Lease, Description [Line Items]
Office space area | ft²			6,000
Base rent			$ 300
Term of contract			5 years
Boston Lease
Lessee, Lease, Description [Line Items]
Current Office Space Under Lease Agreement | ft²		28,000
Renewal term		5 years
Lease not yet commenced, amount		$ 1,000
New Vienna Lease
Lessee, Lease, Description [Line Items]
Office space area | ft²	1,200
Base rent	$ 300
Term of contract	7 years