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Note 8 - Investments, Including Investments Accounted for Using the Equity Method - Schedule of Investments (Details) - USD ($) | Mar. 31, 2023 | Dec. 31, 2022
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Short-term Investments | $ 11,735,816 | $ 6,288,828
Short-term Investments | 11,735,816 | 6,288,828
Long-term investments | 26,136,636 | 26,136,636
U.S. Treasury Notes and Corporate Bonds [Member] |  |
Short-term Investments | 7,953,124 | 4,757,224
Short-term Investments | 7,953,124 | 4,757,224
US Treasury Securities [Member] |  |
Long-term investments | 6,729,457 | 6,729,457
Common Stock Warrants of Sky Harbour Group Corporation [Member] |  |
Short-term Investments | 3,782,692 | 1,531,604
Short-term Investments | 3,782,692 | 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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