Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Stock-based Compensation (Details Textual)

v3.22.2
Note 6 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 6 Months Ended 9 Months Ended
Jun. 30, 2022
Jun. 30, 2021
Jun. 30, 2022
Dec. 31, 2021
Jun. 30, 2022
Jun. 30, 2021
Share-Based Payment Arrangement, Expense $ 638,000 $ 343,055     $ 1,647,000 $ 966,290
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total 4,020,000   $ 4,020,000   $ 4,020,000  
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)         2 years 4 months 24 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)         62,730 105,089
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)         5 years 5 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)         3 years 3 years
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)         $ 66.48 $ 23.74
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)         1 year 10 months 28 days  
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value $ 6,824,000   $ 6,824,000   $ 6,824,000  
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)     5,605 7,678    
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price (in dollars per share)     $ 52.66 $ 32.43    
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) 181,590   181,590   181,590  
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)         29,512  
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  
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)         3,118  
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)         $ 64.11  
Restricted Stock [Member] | Stock Compensation Plan 2007 [Member] | Share-Based Payment Arrangement, Nonemployee [Member] | Director [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)         1 year 1 year
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 318       2,758 2,120
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) $ 62.77       $ 63.35 $ 32.41
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 3 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)         23,318 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)         $ 66.48 $ 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 $ 606,000 328,710     $ 1,552,000 $ 923,256
Cost of Sales [Member]            
Share-Based Payment Arrangement, Expense $ 32,000 $ 14,345     $ 95,000 $ 43,034