Note 7 - Loans Payable (Details Textual) | Sep. 15, 2021USD ($) | Apr. 30, 2021USD ($) | Jan. 28, 2021USD ($) | Jul. 16, 2020USD ($) | Mar. 29, 2019USD ($) | Jan. 24, 2019USD ($) | Mar. 21, 2018USD ($) | Jul. 16, 2020USD ($) | Sep. 30, 2021a | May 20, 2021USD ($) |
Term Loan [Member] | | | | | | | | | | |
Debt Instrument, Face Amount | $ 4,950,000 | | | | | | | | | |
Term Loan [Member] | If Maturity Date Is Extended [Member] | | | | | | | | | | |
Debt Instrument, Covenant, Maximum Loan to Value Ratio of the Property | 70.00% | | | | | | | | | |
Debt Instrument, Covenant, Minimum Debt Service Coverage Ratio | 1.3 | | | | | | | | | |
Debt Instrument, Fee Amount | $ 150 | | | | | | | | | |
Extended Term Loan [Member] | | | | | | | | | | |
Debt Instrument, Amortization Period (Year) | 30 years | | | | | | | | | |
Debt Instrument, Interest Rate, Stated Percentage | 3.75% | | | | | | | | | |
Real Estate Securing Mortgage Loan [Member] | Flowerfield Industrial Park [Member] | | | | | | | | | | |
Area of Real Estate Property (Square Foot) | a | | | | | | | | | 31.8 | |
If Maturity Date Is Extended [Member] | Term Loan [Member] | | | | | | | | | | |
Debt Instrument, Amortization Period (Year) | 25 years | | | | | | | | | |
US Treasury (UST) Interest Rate [Member] | Extended Term Loan [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | 2.75% | | | | | | | | | |
Non-revolving Credit Line [Member] | | | | | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | $ 3,000,000 | | | | | $ 3,000,000 | | | |
Debt Instrument, Interest Only Phase, Term (Month) | | | | | | | 8 months | | | |
Debt Instrument, Interest and Principal Phase, Term (Month) | | 84 months | | | | 84 months | | | | |
Long-term Line of Credit, Total | | $ 2,200,000 | | | | | | | | |
Proceeds from Lines of Credit, Total | | | | | $ 1,100,000 | $ 1,100,000 | | | | |
Debt Instrument, Unused Borrowing Capacity, Amount | | | | | $ 800,000 | | | | | |
Non-revolving Credit Line [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | | | 2.00% | | | | |
Debt Instrument, Amortization Period (Year) | | | | | | 20 years | | | | |
Debt Instrument, Interest Rate, Effective Percentage | | | | | | 3.85% | | | | |
Non-revolving Credit Line [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | | | 3.85% | | | | |
Non-revolving Credit Line 2 [Member] | | | | | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | | | | | $ 3,000,000 | | | | |
Debt Instrument, Interest Only Phase, Term (Month) | | | | | | 24 months | | | | |
Debt Instrument, Interest and Principal Phase, Term (Month) | | | | | | 84 months | | | | |
Long-term Line of Credit, Total | | | | | | | | | | $ 3,000,000 |
Non-revolving Credit Line 2 [Member] | After Interest Only Payment Period [Member] | | | | | | | | | | |
Debt Instrument, Amortization Period (Year) | | | | | | 20 years | | | | |
Debt Instrument, Interest Rate, Effective Percentage | | | | | | 3.85% | | | | |
Non-revolving Credit Line 2 [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | | | 2.00% | | | | |
Non-revolving Credit Line 2 [Member] | Federal Home Loan Bank Rate [Member] | After Interest Only Payment Period [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | | | 3.85% | | | | |
Non-revolving Credit Line 3 [Member] | | | | | | | | | | |
Line of Credit Facility, Maximum Borrowing Capacity | | | | $ 2,500,000 | | | | $ 2,500,000 | | |
Debt Instrument, Interest Only Phase, Term (Month) | | | | | | | | 24 months | | |
Proceeds from Lines of Credit, Total | | | $ 670,235 | $ 379,765 | | | | | | |
Repayments of Debt | $ 1,050,000 | | | | | | | | | |
Non-revolving Credit Line 3 [Member] | Term Loan [Member] | | | | | | | | | | |
Debt Instrument, Term (Year) | 5 years | | | | | | | | | |
Debt Instrument, Extension Term (Year) | 5 years | | | | | | | | | |
Non-revolving Credit Line 3 [Member] | Interest Only Period of Payments [Member] | Minimum [Member] | | | | | | | | | | |
Debt Instrument, Interest Rate, Effective Percentage | | | | 4.75% | | | | 4.75% | | |
Non-revolving Credit Line 3 [Member] | Prime Rate [Member] | Interest Only Period of Payments [Member] | | | | | | | | | | |
Debt Instrument, Basis Spread on Variable Rate | | | | | | | | 1.00% | | |