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Note 8 - Investments, Including Investments Accounted for Using the Equity Method - Schedule of Investments (Details) - USD ($) | Sep. 30, 2023 | Dec. 31, 2022
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Short-term Investments | $ 8,600,527 | $ 6,288,828
Short-term Investments | 8,600,527 | 6,288,828
Long-term investments | 67,852,244 | 26,136,636
U.S. Treasury Notes and Corporate Bonds [Member] |  |
Short-term Investments | 5,448,471 | 4,757,224
Short-term Investments | 5,448,471 | 4,757,224
US Treasury Securities [Member] |  |
Long-term investments | 4,749,166 | 6,729,457
Notes Receivable [Member] |  |
Short-term Investments | 1,608,100 | 0
Short-term Investments | 1,608,100 | 0
Special Purpose Entities [Member] |  |
Long-term investments | 43,695,899 | 0
Common Stock Warrants of Sky Harbour Group Corporation [Member] |  |
Short-term Investments | 1,543,956 | 1,531,604
Short-term Investments | 1,543,956 | 1,531,604
Preferred Stock [Member] |  |
Long-term investments | 348,694 | 348,694
Voting Common Stock of Privately Held Company CB&T Holding Corporation [Member] |  |
Long-term investments | $ 19,058,485 | $ 19,058,485

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