Quarterly report pursuant to Section 13 or 15(d)

Stock Plans Stock-based compensation expense recorded for awards (Details)

v3.19.3
Stock Plans Stock-based compensation expense recorded for awards (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost        
Total stock-based compensation expense $ 128 $ 388 $ 614 $ 1,222
Research and development        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost        
Total stock-based compensation expense 0 136 91 455
General and administrative [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost        
Total stock-based compensation expense $ 128 $ 252 $ 523 $ 767