Annual report pursuant to Section 13 and 15(d)

Stock and Employee Benefit Plans - Stock Based Compensation Expense (Details)

v3.19.1
Stock and Employee Benefit Plans - Stock Based Compensation Expense (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation $ 4,943 $ 3,046
Research and development    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation 1,984 844
General and administrative    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock-based compensation $ 2,959 $ 2,202