XML 78 R51.htm IDEA: XBRL DOCUMENT v3.20.1
Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - Employees And Non Employees - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Total stock-based compensation expense $ 3,694 $ 2,793 $ 470
Research and Development      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Total stock-based compensation expense 1,542 1,236 246
General and Administrative      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Total stock-based compensation expense $ 2,152 $ 1,557 $ 224