Accounts Payable and Accrued Expenses (Schedule of Accounts Payable and Accrued Expenses) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accounts Payable and Accrued Expenses
Accounts payable	$ 5,441	$ 3,512
Research and development	1,432	3,083
Accrued compensation	2,718	2,595
Other	574	554
Total accounts payable and accrued expenses	$ 10,165	$ 9,744