Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Stock-based Compensation (Details Textual)

v3.22.4
Note 6 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 18 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2022
Share-Based Payment Arrangement, Expense $ 660,000 $ 440,000  
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total $ 4,578,000   $ 4,578,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition 2 years 10 months 24 days    
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross 15,020 62,730  
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) 5 years    
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) 3 years    
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) $ 104.36 $ 66.48  
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year) 2 years 10 months 24 days    
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value $ 7,058,000   $ 7,058,000
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     5,585
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price     $ 53.52
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant 176,005   176,005
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) 8,686    
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) 8,686 23,318  
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) $ 104.36 $ 66.48  
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    
Bonus Stock Award [Member] | Share-Based Payment Arrangement, Employee [Member]      
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) 9,144    
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) $ 104.36    
Selling, General and Administrative Expenses [Member]      
Share-Based Payment Arrangement, Expense $ 625,000 $ 409,000  
Cost of Sales [Member]      
Share-Based Payment Arrangement, Expense $ 35,000 $ 31,000