Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Summarizes Fortress warrant activities (Detail)

v3.20.1
Stockholders' Equity - Summarizes Fortress warrant activities (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Subsidiary or Equity Method Investee [Line Items]      
Number of shares, Granted 290,000 490,000  
Warrants [Member]      
Subsidiary or Equity Method Investee [Line Items]      
Number of shares, Outstanding 2,754,189 2,774,189  
Number of shares, Granted 60,000    
Number of shares, Forfeited (73,009) (20,000)  
Number of shares, Outstanding 2,741,180 2,754,189 2,774,189
Number of shares, Exercisable 2,656,180    
Weighted average exercise price, Outstanding $ 3.28 $ 3.30  
Weighted average exercise price, Granted 1.92    
Weighted average exercise price, Forfeited 5.65 5.72  
Weighted average exercise price, Outstanding 3.19 $ 3.28 $ 3.30
Weighted average exercise price, Exercisable $ 3.22    
Total weighted average intrinsic value, Outstanding   $ 2,204,530  
Total weighted average intrinsic value, Granted $ 39,000    
Total weighted average intrinsic value, Outstanding 111,000   $ 2,204,530
Total intrinsic value, Exercisable $ 72,000    
Weighted average remaining contractual life (years), Outstanding     4 years 5 months 19 days
Weighted average remaining contractual life, Granted (years) 19 days    
Weighted average remaining contractual life, Exercisable (years) 2 years 6 months 29 days 3 years 5 months 27 days