Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued Expenses
Accrued payroll and employee benefits	$ 9,348	$ 7,526
Accrued research and development contract costs	10,864	4,223
Accrued professional fees	1,439	766
Other accrued expenses	378	320
Accrued expenses	$ 22,029	$ 12,835