Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - 2015 Inducement Award Plan (Detail)

v3.21.2
Stock-based Compensation - 2015 Inducement Award Plan (Detail) - shares
9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Apr. 30, 2021
Apr. 29, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Option to purchase (shares) 838,750      
2015 Inducement Award Plan        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Possible future issuance under equity compensation plan (in shares) 231,450      
Option to purchase (shares) 182,600 17,500    
Shares authorized under the plan (in shares)     500,000 90,000