Annual report pursuant to Section 13 and 15(d)

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

v3.20.1
Stock-based Compensation - Expense Related to Stock Options (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Stock-based compensation expense related to stock options $ 1,828 $ 1,816
Research and development, net    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Stock-based compensation expense related to stock options 604 519
Selling, general and administrative    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Stock-based compensation expense related to stock options $ 1,224 $ 1,297