Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Narrative (Details)

v3.20.4
Stockholders' Equity - Narrative (Details)
 3 Months Ended 6 Months Ended
Dec. 15, 2020
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Oct. 16, 2020
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Sep. 14, 2020
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Sep. 02, 2020
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Aug. 31, 2020
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Jun. 18, 2020
Jun. 08, 2020
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Jun. 05, 2020
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Feb. 04, 2020
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Jan. 22, 2020
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Mar. 06, 2019
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Jan. 31, 2021
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Oct. 31, 2020
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Jul. 31, 2020
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Oct. 31, 2019
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Oct. 31, 2020
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Oct. 31, 2019
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Apr. 30, 2020
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Dec. 30, 2019
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Dec. 13, 2018
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Nov. 05, 2018
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Mar. 13, 2012
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Stockholders Equity [Line Items]                                            
Preferred stock, shares authorized (in shares)                         1,000,000     1,000,000   1,000,000        
Preferred stock issued (in shares)                         0     0   0        
Preferred stock outstanding (in shares)                         0     0   0        
Common stock, shares authorized (in shares)                         40,000,000     40,000,000   40,000,000        
Common stock issued for stock options exercised for cash | $                         $ 945,332 $ 1,269,982 $ 192,522 $ 2,215,315 $ 237,713          
Number of shares of common stock surrendered (in shares)                               36,000            
Cashless exercise of stock options (in shares)                         36,111                  
Common stock issued for warrants exercised for cash (in shares)                           192,049                
Common stock issued for warrants exercised for cash | $                           $ 1,081,792   $ 1,081,792            
Share price (in dollars per share) | $ / shares       $ 9.49                                    
Proceeds from warrants exercised | $                               1,081,792 $ 0          
Modification charge for warrants exercised | $                               25,966            
Treasury shares cancelled (in shares)   16,667                                        
Retirement of treasury stock | $   $ 70,000                     $ 0     $ 0            
Forecast                                            
Stockholders Equity [Line Items]                                            
Proceeds from issuance of common stock | $                       $ 350,000                    
Equity Distribution Agreement                                            
Stockholders Equity [Line Items]                                            
Common stock, capital shares reserved for future issuance, value | $         $ 12,309,750                                  
Sale of stock, gross proceeds (as a percent)         3.00%                                  
Reimbursement expenses | $         $ 50,000                                  
Total expenses for offering | $         $ 50,000                                  
Subsequent Event | Equity Distribution Agreement                                            
Stockholders Equity [Line Items]                                            
Number of shares sold (in shares) 292,000                                          
Loan Agreements                                            
Stockholders Equity [Line Items]                                            
Warrants granted, exercise price (in dollars per share) | $ / shares                     $ 6.00                      
Convertible Notes | Convertible Notes Payable                                            
Stockholders Equity [Line Items]                                            
Average closing price of common stock (in dollars per share) | $ / shares     $ 10.725             $ 10.725                        
Consecutive trading day period | day     20             20                        
Debt instrument, face amount of loan | $     $ 10,000,000             $ 5,000,000                        
Conversion price (in dollars per share) | $ / shares     $ 7.15             $ 7.15                        
Amortization expense | $                         $ 1,400,000                  
Convertible Notes | Convertible Notes Payable | Common Stock                                            
Stockholders Equity [Line Items]                                            
Debt conversion, converted instrument, shares issued (in shares)     1,398,602                                      
Revolving Credit Facility | Credit Facility Agreement                                            
Stockholders Equity [Line Items]                                            
Exercise price of warrants (in dollars per share) | $ / shares                                         $ 5.85  
Number of securities called by warrants or rights (in shares)                                         92,049  
Cooperman Warrants                                            
Stockholders Equity [Line Items]                                            
Decrease in exercise price of common stock purchase warrants               5.00%                            
Proceeds from warrants exercised | $             $ 1,081,792                              
Number of securities called by warrants or rights (in shares)             192,049                              
Cooperman Warrants | Loan Agreements                                            
Stockholders Equity [Line Items]                                            
Warrants granted, exercise price (in dollars per share) | $ / shares               $ 5.70     $ 6.00                      
Cooperman Warrants | Revolving Credit Facility | Credit Facility Agreement                                            
Stockholders Equity [Line Items]                                            
Exercise price of warrants (in dollars per share) | $ / shares               $ 5.56                         $ 5.85  
Equity Incentive Plan                                            
Stockholders Equity [Line Items]                                            
Number of shares authorized (in shares)                                           3,500,000
Common stock, shares remaining for future issuance (in shares)                         27,560   194,286 27,560 194,286          
2018 Equity Incentive Plan                                            
Stockholders Equity [Line Items]                                            
Number of shares authorized (in shares)                                     1,100,000 500,000    
Common Stock                                            
Stockholders Equity [Line Items]                                            
Common stock issued for stock options exercised for cash (in shares)                         502,412 415,175 90,950 917,587 112,826          
Common stock issued for stock options exercised for cash | $                         $ 502   $ 90 $ 918 $ 113          
Common stock issued for cashless stock options exercised (in shares)                         22,339   80,313 22,339 182,207          
Common stock issued for vested restricted stock units (in shares)                         132,109     132,109            
Common stock issued for warrants exercised for cash (in shares)                               192,049            
Common stock issued for warrants exercised for cash | $                               $ 192            
Share price (in dollars per share) | $ / shares                 $ 9.49                          
Treasury shares cancelled (in shares)                         16,667     16,667            
Retirement of treasury stock | $                         $ 17     $ 17            
Restricted Stock                                            
Stockholders Equity [Line Items]                                            
Unvested shares of restricted common stock outstanding (in shares)                         16,448   69,672 16,448 69,672          
Total unrecognized compensation expense | $                         $ 49,125   $ 249,000 $ 49,125 $ 249,000          
Weighted average recognition period                               1 year 1 month 6 days            
Compensation expense | $                         10,529     $ 21,053            
Unrecognized compensation costs | $                         $ 49,000     $ 49,000            
Restricted Stock Units (RSUs)                                            
Stockholders Equity [Line Items]                                            
Unvested shares of restricted common stock outstanding (in shares)                         669,800   0 669,800 0 643,175        
Total unrecognized compensation expense | $                         $ 4,500,000     $ 4,500,000            
Restricted shares granted (in shares)                 375,000             169,043            
Vesting period of award (in years)                               3 years            
Weighted average recognition period           4 years                   1 year 9 months 18 days            
Award vesting rights (as a percent)           50.00%                                
Derived service period of award                 7 months 20 days                          
Amortization expense | $                         $ 1,200,000                  
Vested (in shares)                         131,250     138,168            
Compensation expense | $                         $ 1,678,622     $ 1,986,474            
Unrecognized compensation costs | $                         4,500,000     4,500,000            
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Tranche One                                            
Stockholders Equity [Line Items]                                            
Restricted shares granted (in shares)         37,500                                  
Minimum closing price of common stock (in dollars per share) | $ / shares         $ 9       $ 9                          
Consecutive trading days         20 days       20 days                          
Award vesting rights (as a percent)         10.00%       10.00%                          
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Tranche Two                                            
Stockholders Equity [Line Items]                                            
Restricted shares granted (in shares)       93,750                                    
Minimum closing price of common stock (in dollars per share) | $ / shares       $ 10         $ 10                          
Consecutive trading days       20 days         20 days                          
Award vesting rights (as a percent)       25.00%         25.00%                          
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Tranche Three                                            
Stockholders Equity [Line Items]                                            
Total unrecognized compensation expense | $                         $ 1,800,000     $ 1,800,000            
Minimum closing price of common stock (in dollars per share) | $ / shares                 $ 12                          
Consecutive trading days                 20 days                          
Restricted Stock Units (RSUs) | Minimum                                            
Stockholders Equity [Line Items]                                            
Grant price of award (in dollars per share) | $ / shares                               $ 6.95            
Restricted Stock Units (RSUs) | Maximum                                            
Stockholders Equity [Line Items]                                            
Grant price of award (in dollars per share) | $ / shares                               $ 12.78            
Stock Incentive Plan and Stock Option Grants to Employees and Directors                                            
Stockholders Equity [Line Items]                                            
Cashless exercise of stock options (in shares)                               989,767            
Options granted (in shares)                         0     0            
Stock options                                            
Stockholders Equity [Line Items]                                            
Weighted average recognition period                               1 year 1 month 6 days            
Compensation expense | $                         $ 142,397     $ 311,131            
Unrecognized compensation costs | $                         $ 400,000     $ 400,000