Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Expense Related to Stock Options (Detail)

v3.20.2
Stock-based Compensation - Expense Related to Stock Options (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Stock-based compensation expense related to stock options $ 411 $ 446 $ 821 $ 938
Research and development, net        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Stock-based compensation expense related to stock options 128 165 264 323
Selling, general and administrative        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Stock-based compensation expense related to stock options $ 283 $ 281 $ 557 $ 615