Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts Payable and Accrued Expenses
Accounts payable	$ 2,467	$ 3,079
Accrued compensation	326	414
Research and development	2,289	3,496
Other	583	268
Total accounts payable and accrued expenses	$ 5,665	$ 7,257