Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Stock-based Compensation (Details Textual)

v3.21.2
Note 4 - Stock-based Compensation (Details Textual) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Feb. 29, 2020
Jun. 30, 2021
Dec. 31, 2020
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Share-based Payment Arrangement, Expense   $ 343,055   $ 213,361 $ 966,290 $ 541,884
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total   2,866,298     $ 2,866,298  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)         3 years 2 months 12 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)         105,089 121,350
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)         5 years 5 years 8 months 15 days
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)         3 years 4 years 8 months 15 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, Outstanding, Weighted Average Remaining Contractual Term (Year)         2 years 6 months 18 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value   $ 1,292,691     $ 1,292,691  
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)   9,739 15,011      
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price (in dollars per share)   $ 21.01 $ 11.93      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)   194,873     194,873  
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)         39,807  
Restricted Stock [Member] | Stock Compensation Plan 2007 [Member] | Share-based Payment Arrangement, Nonemployee [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) 1 year       1 year 1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 5,000       2,120 5,830
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) $ 11.01       $ 32.41 $ 10.72
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  
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   $ 328,710   207,653 $ 923,256 $ 526,580
Cost of Sales [Member]            
Share-based Payment Arrangement, Expense   $ 14,345   $ 5,708 $ 43,034 $ 15,304