Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Schedule of stock-based compensation expense) (Details)

v3.20.2
Stockholders' Equity (Schedule of stock-based compensation expense) (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Share-based Compensation $ 606 $ 1,120 $ 2,368 $ 2,174
General and Administrative [Member]        
Share-based Compensation 348 389 1,213 1,058
Research and Development [Member]        
Share-based Compensation $ 258 $ 731 $ 1,155 $ 1,116