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v3.20.2

Note 2 - Shareholders' Equity (Details Textual) - USD ($) |  | 1 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Apr. 25, 2017 | Feb. 29, 2020 | Jun. 30, 2020 | Dec. 31, 2019 | Jun. 30, 2019 | Dec. 31, 2018 | Sep. 30, 2020 | Sep. 30, 2019 | Nov. 13, 2014
Stock Repurchase Program, Remaining Authorized Repurchase Amount |  |  |  |  |  |  | $ 4,980,671 |  | $ 8,000,000
Stock Repurchase Program, Increase in Authorized Amount | $ 4,000,000 |  |  |  |  |  |  |  |
Stock Repurchase Program, Authorized Amount | $ 12,000,000 |  |  |  |  |  |  |  |
Common Stock, Shares Authorized (in shares) |  |  |  |  |  |  | 50,000,000 | 50,000,000 |
Common Stock, Par or Stated Value Per Share (in dollars per share) |  |  |  |  |  |  | $ 0.01 | $ 0.01 |
Preferred Stock, Shares Authorized (in shares) |  |  |  |  |  |  | 500,000 | 500,000 |
Preferred Stock, Shares Issued, Total (in shares) |  |  |  |  |  |  | 0 | 0 |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) |  |  |  |  |  |  | 769,545 |  |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total |  |  |  |  |  |  | $ 1,938,136 |  |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  |  |  |  |  | 3 years 328 days |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  | $ 773,555 | $ 1,729,025 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) |  |  |  |  |  |  | 121,350 | 172,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) |  |  |  |  |  |  | 5 years 259 days | 4 years |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) |  |  |  |  |  |  | 4 years 259 days | 3 years |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) |  |  |  |  |  |  | $ 12.43 | $ 12.17 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number (in shares) |  |  |  |  |  |  | 44,000 | 36,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares) |  |  |  |  |  |  | 26,750 | 7,750 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value |  |  |  |  |  |  | $ 332,468 | $ 81,728 |
Stock Repurchased During Period, Shares (in shares) |  |  |  |  |  |  | 41,796 | 40,933 |
Treasury Stock Acquired, Average Cost Per Share (in dollars per share) |  |  |  |  |  |  | $ 10.26 | $ 13.51 |
Payment, Tax Withholding, Share-based Payment Arrangement |  |  |  |  |  |  | $ 176,416 | $ 553,165 |
Preferred Stock, Shares Outstanding, Ending Balance (in shares) |  |  |  |  |  |  | 0 | 0 |
Employee Stock Purchase Plan [Member] |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) |  |  |  |  |  |  | 219,623 |  |
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) |  |  | 15,116 | 15,107 | 19,923 | 17,312 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price (in dollars per share) |  |  | $ 11.85 | $ 11.23 | $ 8.43 |  |  |  |
Payment, Tax Withholding, Share-based Payment Arrangement |  |  |  |  |  |  | $ 84,595 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares) |  | 200,000 |  |  |  |  |  |  |
Minimum [Member] |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) |  |  |  |  |  |  | 3 years |  |
Maximum [Member] |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) |  |  |  |  |  |  | 5 years |  |
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 |  |
Cashless Method Stock Option Exercised [Member] |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares) |  |  |  |  |  |  | 14,688 | 6,750 |
Restricted Stock [Member] | Minimum [Member] | Employees [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] | Employees [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 |  |  |  |  |  |  | $ 752,011 | $ 1,638,829 |
Cost of Sales [Member] |  |  |  |  |  |  |  |  |
Share-based Payment Arrangement, Expense |  |  |  |  |  |  | $ 21,544 | $ 90,196 |
Undesignated Shares [Member] |  |  |  |  |  |  |  |  |
Preferred Stock, Shares Authorized (in shares) |  |  |  |  |  |  | 5,000,000 |  |
Series B Preferred Stock [Member] |  |  |  |  |  |  |  |  |
Preferred Stock, Shares Authorized (in shares) |  |  |  |  |  |  | 500,000 |  |
Preferred Stock, Shares Issued, Total (in shares) |  |  |  |  |  |  | 0 |  |
Preferred Stock, Shares Outstanding, Ending Balance (in shares) |  |  |  |  |  |  | 0 |  |

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