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 6 Months Ended
Apr. 30, 2020
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Apr. 30, 2018
Schedule Of Available For Sale Securities [Line Items]              
Warrants to purchase common stock   1,592,840   1,592,840   1,297,151  
Fair value of warrants   $ 202 $ 37 $ 200 $ 50    
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   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   $ 43      
Warrant exercisable 133,333            
Warrant exercisable date Dec. 31, 2023            
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