Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued Expenses
Accrued payroll and employee benefits	$ 7,526	$ 7,968
Accrued research and development contract costs	4,223	2,871
Accrued professional fees	766	878
Other accrued expenses	320	283
Accrued expenses	$ 12,835	$ 12,000