Annual report pursuant to Section 13 and 15(d)

Registered Direct Equity Offerings - Additional Information (Detail)

v3.19.2
Registered Direct Equity Offerings - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended
Apr. 05, 2019
Jun. 15, 2018
Feb. 13, 2019
Jul. 26, 2019
May 31, 2019
May 31, 2018
Stockholders Equity Note [Line Items]            
Warrants to purchase common shares, shares       1,984,769    
Investor            
Stockholders Equity Note [Line Items]            
Warrants to purchase common shares, shares         1,000,000 5,000,000
Class of warrants, exercise price           $ 0.30
Term of warrants           5 years
Placement Agent            
Stockholders Equity Note [Line Items]            
Warrants to purchase common shares, shares 938,790 133,600 965,563      
Class of warrants, exercise price $ 0.50 $ 0.55 $ 0.50      
Term of warrants 5 years 5 years 5 years      
Percentage of shares, issued as warrants 9.00% 8.00% 9.00%      
Subscription Agreements            
Stockholders Equity Note [Line Items]            
Number of shares to be sold 10,931,000 1,970,000 10,728,480      
Purchase price, per share $ 0.50 $ 0.50 $ 0.50      
Warrants to purchase common shares, shares   1,970,000        
Class of warrants, exercise price   $ 0.75        
Term of warrants   5 years        
Proceeds from issuance of common shares   $ 0.9        
2019 Subscription Agreement            
Stockholders Equity Note [Line Items]            
Warrants to purchase common shares, shares 5,465,500   5,364,240      
Class of warrants, exercise price $ 0.50   $ 0.50      
Term of warrants 5 years   5 years      
Proceeds from issuance of common shares $ 5.0   $ 4.8