Quarterly report pursuant to Section 13 or 15(d)

SHAREHOLDERS' EQUITY, Stock Option Activity (Details)

v3.21.2
SHAREHOLDERS' EQUITY, Stock Option Activity (Details)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Jan. 13, 2021
USD ($)
item
$ / shares
shares
May 31, 2021
USD ($)
$ / shares
shares
May 31, 2020
USD ($)
shares
May 31, 2021
USD ($)
$ / shares
shares
May 31, 2020
USD ($)
shares
Aug. 31, 2020
USD ($)
$ / shares
shares
Aug. 30, 2020
shares
Stock Options [Abstract]              
Share-based compensation expense | $       $ 404 $ 435    
2014 Equity Plan [Member]              
Shareholders' Equity [Abstract]              
Shares reserved for issuance (in shares)   1,600,000   1,600,000      
Shares available for grant (in shares)   974,965   974,965     1,088,500
2004 Incentive Plan and 2014 Equity Plan [Member]              
Number of Options [Roll Forward]              
Outstanding, beginning of period (in shares)       661,500      
Granted (in shares)       115,000      
Exercised (in shares)       (18,000)      
Net settlement exercised (in shares)     0 (37,500) 0    
Outstanding, end of period (in shares)   721,000   721,000   661,500  
Options exercisable (in shares)   502,667   502,667      
Weighted Average Exercise Price [Roll Forward]              
Outstanding, beginning of period (in dollars per share) | $ / shares       $ 7.23      
Granted (in dollars per share) | $ / shares       9.00      
Exercised (in dollars per share) | $ / shares       3.41      
Net settlement exercised (in dollars per share) | $ / shares       3.99      
Outstanding, end of period (in dollars per share) | $ / shares   $ 7.77   7.77   $ 7.23  
Options exercisable (in dollars per share) | $ / shares   $ 6.92   $ 6.92      
Stock Options [Abstract]              
Weighted average remaining contractual term       6 years 3 months 18 days   6 years 2 months 1 day  
Weighted average remaining contractual term, options exercisable       5 years 2 months 19 days      
Approximate aggregate intrinsic value, outstanding | $   $ 4,592   $ 4,592   $ 1,831  
Approximate aggregate intrinsic value, options exercisable | $   3,627   3,627      
Share-based compensation expense | $   $ 100 $ 100 $ 400 $ 400    
Shares issued (in shares)   8,758   24,035      
Options cancelled (in shares)   4,242   13,465      
2004 Incentive Plan and 2014 Equity Plan [Member] | Non-Employee Board Members [Member]              
Number of Options [Roll Forward]              
Granted (in shares) 2,000            
Stock Options [Abstract]              
Number of board members | item 6            
Stock price (in dollars per share) | $ / shares $ 11.33            
Share-based compensation expense | $ $ 100