Annual report pursuant to Section 13 and 15(d)

Convertible Instruments - Additional Information (Detail)

v3.19.2
Convertible Instruments - Additional Information (Detail)
 1 Months Ended 9 Months Ended 12 Months Ended
Jun. 26, 2018
USD ($)
$ / shares
Jan. 31, 2018
USD ($)
$ / shares
shares
Jan. 30, 2019
USD ($)
Nov. 15, 2018
USD ($)
$ / shares
Feb. 28, 2019
USD ($)
$ / shares
shares
May 31, 2019
USD ($)
$ / shares
shares
May 31, 2018
USD ($)
$ / shares
shares
May 31, 2017
USD ($)
May 31, 2010
USD ($)
$ / shares
shares
Jul. 26, 2019
shares
May 14, 2019
$ / shares
Mar. 20, 2019
$ / shares
shares
Apr. 30, 2010
shares
Class of Stock [Line Items]                          
Preferred Stock, Share issuance price | $ / shares                     $ 0.40    
Common stock, shares authorized | shares           700,000,000 375,000,000           100,000,000
Convertible preferred stock, par value | $ / shares           $ 0.001              
Common stock, par value | $ / shares           $ 0.001              
Common stock warrants to purchase shares | shares                   1,984,769      
Amortization of debt discount           $ 1,707,068 $ 1,666,017 $ 0          
Amortization of debt issuance costs           $ 459,085 435,609 0          
Number of shares to be sold | shares           3,756,406              
Proceeds from sale of common stock and warrant           $ 38,268,839 25,224,212 19,133,755          
Repayment of note           0 259,157 0          
Interest expense           $ 950,617 251,315 0          
Convertible promissory note maturity period           2 years              
Proceeds from convertible promissory note     $ 5,000,000                    
Investor Warrants                          
Class of Stock [Line Items]                          
Common stock warrants to purchase shares | shares         5,460,000                
Conversion of Preferred Stock to Common Stock                          
Class of Stock [Line Items]                          
Undeclared dividend           $ 216,000 199,000            
Accrued dividend           432,000 $ 387,000            
Short-Term Convertible Notes                          
Class of Stock [Line Items]                          
Conversion price | $ / shares             $ 0.75            
Convertible note, aggregate principal             $ 4,890,000            
Convertible note maturity date   Jan. 31, 2018                      
Convertible notes, interest rate             7.00%            
Common stock warrants to purchase shares | shares   7,718,010                      
Unamortized discount           0              
Payment obligation against which common stock issued   $ 5,788,500                      
Accrued but unpaid interest   $ 243,000                      
Number of shares to be sold | shares   12,062,728                      
Sale of Stock, Price Per Share | $ / shares   $ 0.50                      
Proceeds from sale of common stock and warrant   $ 6,000,000                      
Repayment of note   $ 259,000       250,000              
Interest expense           0 $ 75,000            
Net carrying value of note           $ 0              
Short-Term Convertible Notes | Investor Warrants                          
Class of Stock [Line Items]                          
Common stock warrants to purchase shares | shares           4,025,656              
Exercise price of warrants, per share | $ / shares           $ 1.00              
Term of warrants           5 years              
Short-Term Convertible Notes | Detachable Common Stock Warrants                          
Class of Stock [Line Items]                          
Unamortized discount           $ 4,200,000 1,500,000 92,000          
Amortization of debt discount           1,700,000 1,600,000 $ 0          
Unamortized issuance costs             400,000            
Amortization of debt issuance costs           0 400,000            
Note                          
Class of Stock [Line Items]                          
Convertible notes, interest rate 10.00%                        
Interest expense         $ 1,500,000 386,000 0            
Convertible promissory note principle amount $ 5,700,000                        
Proceeds from convertible promissory note $ 5,000,000                        
Common stock conversion price | $ / shares $ 0.55     $ 0.55                  
Convertible promissory note maximum redemption amount $ 350,000     $ 350,000                  
Convertible promissory note redemption description The Investor may redeem any portion of the June 2018 Note, at any time after six months from the issue date upon five trading days' notice, subject to a maximum monthly redemption amount of $350,000.     Effective November 15, 2018, the June 2018 Note was amended to allow the Investor to redeem the monthly redemption amount of $350,000 in cash or stock, at the lesser of (i) $0.55, or (ii) the lowest closing bid price of the Company's common stock during the 20 days prior to the conversion, multiplied by a conversion factor of 85%.                  
Terms of conversion 1.5                        
Convertible note, redeemed amount           1,455,000              
Outstanding balance of convertible note including accrued unpaid interest           4,500,000              
Fair value of Note           6,900,000              
Net carrying value of note           5,400,000              
2019 Short Term Convertible Notes                          
Class of Stock [Line Items]                          
Conversion price | $ / shares         $ 0.50                
Convertible note, aggregate principal         $ 5,500,000                
Convertible notes, interest rate         10.00%                
Unamortized discount           1,469,625 0            
Amortization of debt discount           800,000              
Unamortized issuance costs           404,340 0            
Amortization of debt issuance costs           1,700,000              
Payment obligation against which common stock issued         $ 972,000                
Sale of Stock, Price Per Share | $ / shares         $ 0.50                
Proceeds from sale of common stock and warrant         $ 583,200                
Interest expense           213,000 0            
Net carrying value of note           3,586,035 0            
2019 Short Term Convertible Notes | Investor Warrants                          
Class of Stock [Line Items]                          
Exercise price of warrants, per share | $ / shares         $ 0.30                
Term of warrants         5 years                
2019 Short Term Convertible Notes | Detachable Common Stock Warrants                          
Class of Stock [Line Items]                          
Amortization of debt discount           3,000,000              
2019 Short Term Convertible Notes | Conversion of Preferred Stock to Common Stock                          
Class of Stock [Line Items]                          
Amortization of debt issuance costs           $ 500,000              
January 2019 Note [Member]                          
Class of Stock [Line Items]                          
Convertible notes, interest rate           10.00%              
Common stock warrants to purchase shares | shares           5,000,000              
Exercise price of warrants, per share | $ / shares           $ 0.30              
Term of warrants           5 years              
Unamortized discount           $ 600,000              
Unamortized issuance costs           100,000              
Interest expense           126,000 $ 0            
Convertible promissory note principle amount           5,700,000              
Proceeds from convertible promissory note           $ 5,000,000              
Common stock conversion price | $ / shares           $ 0.50              
Convertible promissory note redemption description             The Investor may redeem any portion of the January 2019 Note, at any time after six months from the issue date upon five trading days’ notice, subject to a maximum monthly redemption amount of $350,000. The monthly redemption amount may be paid in cash or stock, at the Company’s election, at the lesser of (i) $0.50, or (ii) the lowest closing bid price of the Company’s common stock during the 20 days prior to the conversion, multiplied by a conversion factor of 85%.            
Company Reserves Shares For Future Conversition | shares           20,000,000              
Common Stock                          
Class of Stock [Line Items]                          
Number of common shares issued upon conversion of preferred stock | shares           10              
Conversion price | $ / shares           $ 0.50              
Series B Convertible Preferred Stock                          
Class of Stock [Line Items]                          
Series C Convertible preferred stock, shares issued | shares | shares           92,100 92,100   400,000        
Preferred Stock, Share issuance price | $ / shares           $ 5.00              
Cash proceeds                 $ 2,009,000        
Series B Convertible preferred stock, shares outstanding | shares | shares           92,100 92,100            
Constructive dividend to Preferred stock holders           $ 6,000,000              
Liquidation preference on common shares | $ / shares           $ 5.00              
Dividends are payable to preferred stock holders | $ / shares           0.25              
Convertible preferred stock, par value | $ / shares           $ 0.001 $ 0.001   $ 0.001        
Series C Convertible Preferred Stock                          
Class of Stock [Line Items]                          
Series C Convertible preferred stock, shares issued | shares | shares           3,246           3,246  
Preferred Stock, Share issuance price | $ / shares           $ 1,000.00              
Cash proceeds           $ 3,083,700              
Series B Convertible preferred stock, shares outstanding | shares | shares           3,246              
Common stock, shares authorized | shares                       5,000  
Convertible preferred stock, par value | $ / shares           $ 0.001           $ 0.001  
Placement agent fee           $ 162,300              
Preferred Stock, Dividend Rate, Percentage           10.00%              
Convertible Preferred Stock Conversion Price | $ / shares           $ 0.50              
Accrued dividends           $ 37,351 $ 0            
Accrued dividend Shares | shares           130,000