Note D - Income Taxes (Tables)
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12 Months Ended | 
Sep. 30, 2016  | 
| Notes Tables | 
 
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| Summary of Valuation Allowance [Table Text Block] | 
  | Year Ended |    |  Balance at Beginning of Year |    |  Income Tax Benefit |    |  Reversal for State NOL Expiration and Utilization |    |  Balance at End of Year |     | September 30, 2016 |    |  $ |  658,808 |    |    |  $ |  (78,044 |  ) |    |  $ |  (258,360 |  ) |    |  $ |  322,404 |    |     | September 30, 2015 |    |    |  847,826 |    |    |    |  (53,836 |  ) |    |    |  (135,182 |  ) |    |    |  658,808 |    |     | September 30, 2014 |    |    |  975,258 |    |    |    |  - |    |    |    |  (127,432 |  ) |    |    |  847,826 |    |      
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| Schedule of Deferred Tax Assets and Liabilities [Table Text Block] | 
  |   |    |  September 30, 2016 |    |  September 30, 2015 |     | Current deferred income tax assets (liabilities): |    |    |    |    |    |    |    |    |     | Inventories |    |  $ |  - |    |    |  $ |  309,791 |    |     | Accrued expenses and reserves |    |    |  - |    |    |    |  261,452 |    |     | Prepaid expenses |    |    |  - |    |    |    |  (42,304 |  ) |     | Net operating loss carry forwards and credits |    |    |  - |    |    |    |  652,533 |    |     |   |    |    |  - |    |    |    |  1,181,472 |    |     | Valuation allowance |    |    |  - |    |    |    |  (34,573 |  ) |     | Net current deferred tax asset |    |  $ |  - |    |    |  $ |  1,146,899 |    |     |   |    |    |    |    |    |    |    |    |     | Long-term deferred income tax assets (liabilities): |    |    |    |    |    |    |    |    |     | Intangibles |    |  $ |  (67,450 |  ) |    |  $ |  (39,819 |  ) |     | Property and equipment depreciation |    |    |  (815,374 |  ) |    |    |  (726,035 |  ) |     | Net operating loss carry forwards and credits |    |    |  702,113 |    |    |    |  938,168 |    |     | Stock-based compensation |    |    |  221,905 |    |    |    |  49,926 |    |     | Inventories |    |    |  388,292 |    |    |    |  - |    |     | Prepaid expenses |    |    |  (44,511 |  ) |    |    |  - |    |     | Accrued expenses and reserves |    |    |  312,227 |    |    |    |  25,887 |    |     | Goodwill |    |    |  (786,577 |  ) |    |    |  (706,779 |  ) |     |   |    |    |  (89,375 |  ) |    |    |  (458,652 |  ) |     | Valuation allowance |    |    |  (322,404 |  ) |    |    |  (624,235 |  ) |     | Net long-term deferred tax liability |    |  $ |  (411,779 |  ) |    |  $ |  (1,082,887 |  ) |      
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| Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] | 
  |   |    |  September 30, 2016 |    |  September 30, 2015 |    |  September 30, 2014 |     | Federal statutory rate |    |    |  34 |  % |    |    |  34 |  % |    |    |  34 |  % |     | State income taxes |    |    |  1 |  % |    |    |  1 |  % |    |    |  1 |  % |     | Permanent differences |    |    |  - |    |    |    |  1 |  % |    |    |  2 |  % |     | Change in valuation allowance |    |    |  (3 |  %) |    |    |  (3 |  %) |    |    |  (1 |  %) |     | Expiration of state NOL’s |    |    |  2 |  % |    |    |  2 |  % |    |    |  1 |  % |     | Research and development credits |    |    |  (1 |  %) |    |    |  - |    |    |    |  - |    |     | Excess tax benefits from stock-based compensation (adoption of ASU 2016-09) |    |    |  (7 |  %) |    |    |  - |    |    |    |  - |    |     | Tax rate |    |    |  26 |  % |    |    |  35 |  % |    |    |  37 |  % |      
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| Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] | 
  |   |    |  September 30, 2016 |    |  September 30, 2015 |    |  September 30, 2014 |     | Current: |    |    |    |    |    |    |    |    |    |    |    |    |     | Federal |    |  $ |  428,638 |    |    |  $ |  67,373 |    |    |  $ |  115,049 |    |     | State |    |    |  106,623 |    |    |    |  65,820 |    |    |    |  46,303 |    |     |   |    |    |  535,261 |    |    |    |  133,193 |    |    |    |  161,352 |    |     | Deferred: |    |    |    |    |    |    |    |    |    |    |    |    |     | Federal |    |    |  2,434,294 |    |    |    |  2,377,590 |    |    |    |  2,903,110 |    |     | State |    |    |  (93,523 |  ) |    |    |  (35,545 |  ) |    |    |  116,516 |    |     |   |    |    |  2,340,771 |    |    |    |  2,342,045 |    |    |    |  3,019,626 |    |     | Income tax expense |    |  $ |  2,876,032 |    |    |  $ |  2,475,238 |    |    |  $ |  3,180,978 |    |      
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