Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.2
Stock Plans - Stock-based compensation expense recorded for awards (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost        
Total stock-based compensation expense $ 350 $ 402 $ 486 $ 834
Research and development        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost        
Total stock-based compensation expense 14 156 91 318
General and administrative        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost        
Total stock-based compensation expense $ 336 $ 246 $ 395 $ 516