Accrued Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accrued Expense
Accrued expense	$ 1,025	$ 975
Accrued clinical trial expenses	300	400
Accrued Vacation And Bonus	500	400
Manufacturing expense		100
Accrued Legal And Patent Fees	100
Other Accrued Liabilities	$ 100	$ 100