Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Additional Information (Detail)

v3.20.2
Financial Instruments - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Apr. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Apr. 30, 2018
Schedule Of Available For Sale Securities [Line Items]            
Warrants to purchase common stock     1,592,840   1,297,151  
Fair value of warrants   $ (57) $ 200 $ (7)    
Compensation Warrant [Member]            
Schedule Of Available For Sale Securities [Line Items]            
Warrants to purchase common stock 50,000          
Warrant exercise price $ 3.01          
Fair value of warrants     59      
Warrant exercisable date Dec. 31, 2021          
Performance Warrant [Member]            
Schedule Of Available For Sale Securities [Line Items]            
Warrants to purchase common stock 400,000          
Warrant exercise price $ 3.01          
Fair value of warrants     $ 43      
Warrant exercisable 133,333          
Warrant exercisable date Dec. 31, 2023          
Performance Warrant [Member] | First Installment [Member]            
Schedule Of Available For Sale Securities [Line Items]            
Warrant exercisable 133,333          
April 2018 Warrant [Member]            
Schedule Of Available For Sale Securities [Line Items]            
Warrants to purchase common stock           20,000
Warrant exercise price           $ 11.73
Fair value of warrants           $ 207