Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Schedule of Stock-based Compensation Related to Stock Awards (Detail)

v3.20.4
Stockholders' Equity - Schedule of Stock-based Compensation Related to Stock Awards (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]      
Total stock-based compensation expense $ 51,351 $ 51,696 $ 33,817
Research and development      
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]      
Total stock-based compensation expense 31,527 26,773 16,211
General and administrative      
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]      
Total stock-based compensation expense $ 19,824 $ 24,923 $ 17,606