Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Stock-based Compensation (Details Textual)

v3.22.1
Note 6 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Mar. 31, 2022
Dec. 31, 2021
Mar. 31, 2021
Mar. 31, 2022
Mar. 31, 2021
Share-Based Payment Arrangement, Expense $ 570,000   $ 334,000 $ 1,010,000 $ 623,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total 4,694,000     $ 4,694,000  
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)       2 years 7 months 6 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)       2 years 1 month 13 days  
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value $ 7,482,000     $ 7,482,000  
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)       7,678  
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price (in dollars per share)       $ 32.43  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)   187,195      
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 1 year
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 2,758 318   3,118 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) $ 63.35 $ 62.77   $ 64.11 $ 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 $ 538,000   314,000 $ 947,000 $ 595,000
Cost of Sales [Member]          
Share-Based Payment Arrangement, Expense $ 32,000   $ 20,000 $ 63,000 $ 28,000