Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Stock-based Compensation (Details Textual)

v3.20.4
Note 4 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Payment Arrangement, Expense $ 289,057 $ 240,586
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total $ 3,429,805  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) 3 years 255 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) 105,089 116,600
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) 5 years 5 years 284 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 3 years 4 years 284 days
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) $ 23.74 $ 12.43
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share) $ 8.14  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year) 2 years 237 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value $ 1,173,691  
Proceeds from Stock Options Exercised $ 85 $ 2,580
Employee Stock Purchase Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Market Price Percentage, Offering Date 85.00%  
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares) 15,011 15,107
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price (in dollars per share) $ 11.93 $ 11.23
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) 204,612  
Share-based Payment Arrangement, Option [Member] | Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 3 years  
Share-based Payment Arrangement, Option [Member] | Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 5 years  
Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 37,687  
Restricted Stock [Member] | Stock Compensation Plan 2007 [Member] | Share-based Payment Arrangement, Employee [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 3 years  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 37,687 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Intrinsic Value, Amount Per Share (in dollars per share) $ 23.74  
Restricted Stock [Member] | Minimum [Member] | Stock Compensation Plan 2007 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 1 year  
Restricted Stock [Member] | Maximum [Member] | Stock Compensation Plan 2007 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 10 years  
Selling, General and Administrative Expenses [Member]    
Share-based Payment Arrangement, Expense $ 280,889 $ 235,788
Cost of Sales [Member]    
Share-based Payment Arrangement, Expense $ 8,168 $ 4,798