Quarterly report pursuant to Section 13 or 15(d)

SHAREHOLDERS' EQUITY, Equity Compensation Plan (Details)

v3.20.2
SHAREHOLDERS' EQUITY, Equity Compensation Plan (Details)
 3 Months Ended 9 Months Ended 12 Months Ended
Jan. 15, 2020
BoardMember
$ / shares
shares
Sep. 27, 2019
$ / shares
shares
Sep. 25, 2019
$ / shares
shares
May 31, 2020
USD ($)
$ / shares
shares
May 31, 2019
USD ($)
May 31, 2020
USD ($)
$ / shares
shares
May 31, 2019
USD ($)
Aug. 31, 2019
USD ($)
$ / shares
shares
Stock Options [Abstract]                
Share-based compensation expense | $       $ 81,900 $ 96,100 $ 435,109 $ 257,813  
Non Employee [Member]                
Number of Options [Roll Forward]                
Granted (in shares) | shares 2,000              
Stock Options [Abstract]                
Number of board members | BoardMember 6              
Stock price (in dollars per share) | $ / shares $ 12.45              
Share-based compensation expense | $       $ 0 0 $ 149,400 0  
2014 Equity Plan [Member]                
Shareholders' Equity [Abstract]                
Reserved shares of common stock for issuance (in shares) | shares       1,600,000   1,600,000    
2004 Incentive Plan and 2014 Equity Plan [Member]                
Number of Options [Roll Forward]                
Outstanding, beginning of period (in shares) | shares           555,500    
Granted (in shares) | shares           130,000    
Exercised (in shares) | shares           (15,000)    
Forfeited or expired (in shares) | shares           0    
Outstanding, end of period (in shares) | shares       670,500   670,500   555,500
Options exercisable (in shares) | shares       490,500   490,500    
Weighted Average Exercise Price [Roll Forward]                
Outstanding, beginning of period (in dollars per share) | $ / shares           $ 6.33    
Granted (in dollars per share) | $ / shares           10.41    
Exercised (in dollars per share) | $ / shares           2.67    
Forfeited or expired (in dollars per share) | $ / shares           0    
Outstanding, end of period (in dollars per share) | $ / shares       $ 7.20   7.20   $ 6.33
Options exercisable (in dollars per share) | $ / shares       $ 6.07   $ 6.07    
Stock Options [Abstract]                
Weighted average remaining contractual term           6 years 4 months 13 days   6 years 3 months 7 days
Weighted average remaining contractual term, options exercisable           5 years 5 months 1 day    
Approximate aggregate intrinsic value, outstanding | $       $ 2,066,420   $ 2,066,420   $ 2,527,590
Approximate aggregate intrinsic value, options exercisable | $       2,023,755   $ 2,023,755    
Weighted average grant-date fair value (in dollars per share) | $ / shares           $ 4.19    
Share-based compensation expense | $       $ 81,900 $ 96,100 $ 435,100 $ 257,800  
2004 Incentive Plan and 2014 Equity Plan [Member] | Senior Management [Member]                
Number of Options [Roll Forward]                
Granted (in shares) | shares   50,000            
Stock Options [Abstract]                
Weighted average grant-date fair value (in dollars per share) | $ / shares   $ 4.16            
Vesting period           3 years    
2004 Incentive Plan and 2014 Equity Plan [Member] | Senior Management [Member] | Maximum [Member]                
Stock Options [Abstract]                
Expiration period           10 years    
2004 Incentive Plan and 2014 Equity Plan [Member] | Employee [Member]                
Number of Options [Roll Forward]                
Granted (in shares) | shares     80,000          
Stock Options [Abstract]                
Weighted average grant-date fair value (in dollars per share) | $ / shares     $ 4.21          
Vesting period           3 years    
2004 Incentive Plan and 2014 Equity Plan [Member] | Employee [Member] | Maximum [Member]                
Stock Options [Abstract]                
Expiration period           10 years