Accrued Expense (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accrued Expense
Accrued expense	$ 682	$ 673
Accrued Vacation And Bonus	400	400
Accrued Clinical And Preclinical Expenses	100	200
Accrued Legal And Patent Fees	100
Other Accrued Liabilities	$ 100	$ 100