Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Schedule of Stock-based Compensation Related to All Employee And Non-employee Stock Awards (Detail)

v3.20.2
Stockholders' Equity - Schedule of Stock-based Compensation Related to All Employee And Non-employee Stock Awards (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]        
Total stock-based compensation expense $ 13,948 $ 15,201 $ 26,592 $ 27,470
Research and development        
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]        
Total stock-based compensation expense 8,540 6,672 16,190 12,737
General and administrative        
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]        
Total stock-based compensation expense $ 5,408 $ 8,529 $ 10,402 $ 14,733