Quarterly report pursuant to Section 13 or 15(d)

Stock Plan and Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail)

v3.20.1
Stock Plan and Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Stock-based compensation expense $ 1,998 $ 2,342
Research and Development [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Stock-based compensation expense 444 1,112
General and Administrative [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Stock-based compensation expense $ 1,554 $ 1,230