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Note 8 - Investments, Including Investments Accounted for Using the Equity Method (Details Textual) - USD ($) |  |  |  |  | 1 Months Ended | 3 Months Ended | 4 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
May 01, 2023 | Jan. 25, 2022 | Sep. 14, 2021 | May 31, 2018 | Oct. 31, 2020 | Jan. 31, 2018 | Jun. 30, 2023 | Mar. 31, 2023 | Jun. 30, 2022 | Mar. 31, 2022 | Nov. 30, 2020 | Jun. 30, 2023 | Jun. 30, 2022 | Dec. 31, 2022 | Apr. 30, 2023
Debt Securities, Trading |  |  |  |  |  |  | $ 69,490,548 |  |  |  |  | $ 69,490,548 |  | $ 33,520,401 |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) |  |  |  |  |  |  | $ 9.95 |  |  |  |  | $ 9.95 |  | $ 9.95 |
Deconsolidation, Gain (Loss), Amount |  |  |  |  |  |  | $ 0 |  | $ 0 |  |  | $ 0 | $ 24,977,740 |  |
Deconsolidation, Gain (Loss), Recognized, Amount |  |  |  |  |  |  |  |  |  |  |  | 0 |  | $ 10,010,090 |
Yellowstone Acquisition Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  |  |  |  |  |  |  |  |  |  | 20.00% |  |  |  |
Sky Harbour Group Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Equity Method Investments |  |  | $ 55,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Sky Harbour Group Corporation Class A Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity Method Investment, Ownership Percentage |  |  |  |  |  |  |  | 22.95% |  | 22.95% |  |  |  |  |
Payments to Acquire Equity Method Investments |  | $ 45,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Equity Method Investment, Shares, Converted from Other Equity (in shares) |  | 5,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Equity Method Investment, Price Per Share (in dollars per share) |  | $ 10 |  |  |  |  |  |  |  |  |  |  |  |  |
Equity Method Investment, Shares (in shares) |  | 4,500,000 |  |  |  |  |  | 13,118,474 |  | 13,118,474 |  |  |  |  |
Deconsolidation, Gain (Loss), Amount |  |  |  |  |  |  |  |  |  | $ 24,977,740 |  |  |  |  |
Deconsolidation, Gain (Loss), Recognized, Amount |  |  |  |  |  |  |  |  |  | 10,000,000 |  |  |  |  |
Deconsolidation, Gain (Loss), Assets and Liabilities |  |  |  |  |  |  |  |  |  | $ 15,000,000 |  |  |  |  |
Equity Method Investment, Quoted Market Value |  |  |  |  |  |  | $ 62,000,000 |  |  |  |  | $ 62,000,000 |  |  |
Equity Method Investments, Price Per Share (in dollars per share) |  |  |  |  |  |  | $ 7.78 |  |  |  |  | $ 7.78 |  |  |
Yellowstone Acquisition Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance Initial Public Offering |  |  |  |  | $ 125,000,000 |  |  |  |  |  |  |  |  |  |
Yellowstone Acquisition Company [Member] | IPO [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Units Issued During Period, Number (in shares) |  |  |  |  | 13,598,898 |  |  |  |  |  |  |  |  |  |
Units Issued During Period, Price Per Unit (in dollars per share) |  |  |  |  | $ 10.00 |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) |  |  |  |  | 11.50 |  |  |  |  |  |  |  |  |  |
Sale of Unit, Price Per Unit (in dollars per share) |  |  |  |  | $ 10.00 |  |  |  |  |  |  |  |  |  |
Yellowstone Acquisition Company [Member] | IPO [Member] | Common Class A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Units Issued During Period, Number of Common Stock, Shares (in shares) |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |
Yellowstone Acquisition Company Warrants [Member] | IPO [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Units Issued During Period, Number of Warrants (in shares) |  |  |  |  | 0.5 |  |  |  |  |  |  |  |  |  |
BOC Yellowstone LLC [Member] | Non-redeemable Private Placement Warrants [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) |  |  |  |  |  |  |  |  |  |  | $ 11.50 |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) |  |  |  |  |  |  |  |  |  |  | 7,719,779 |  |  |  |
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |
The 24th Street Asset Management, LLC [Member] | Boston Omaha Asset Management, LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition, Percentage of Voting Interests Acquired | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred | $ 5,016,494 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 48.00%
Payments to Acquire Businesses, Gross | $ 2,759,072 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | 45,644 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain | $ 4,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
The 24th Street Asset Management, LLC [Member] | Boston Omaha Asset Management, LLC [Member] | Holdback Cash Consideration [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross | $ 1,254,102 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Combination Agreement with SHG [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross |  |  | $ 55,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition, Backstop Agreed to Be Provided to Acquiree, Maximum Value |  | $ 45,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition, Backstop Agreed to Be Provided to Acquiree, Price Per Share (in dollars per share) |  | $ 10 |  |  |  |  |  |  |  |  |  |  |  |  |
Breezeway Homes Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Dividend Rate, Per-Dollar-Amount (in dollars per share) |  |  |  |  |  | $ 2,665 |  |  |  |  |  |  |  |  |
Preferred Stock [Member] | Breezeway Homes Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Conversion, Converted Instrument, Shares Issued (in shares) |  |  |  |  |  | 31,227 |  |  |  |  |  |  |  |  |
Voting Common Stock of Privately Held Company CB&T Holding Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Long-term Investments |  |  |  | $ 19,058,485 |  |  |  |  |  |  |  |  |  |  |
Cost Method Investment, Ownership Percentage |  |  |  | 15.60% |  |  |  |  |  |  |  |  |  |  |
Equity Investments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other than Temporary Impairment Losses, Investments |  |  |  |  |  |  |  | $ 0 |  |  |  |  |  |  |
Class B Common Stock of Yellowstone Acquisition Company [Member] | BOC Yellowstone LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Investments, Total |  |  |  |  |  |  |  |  |  |  | $ 7,800,000 |  |  |  |
Investment Owned, Balance, Shares (in shares) |  |  |  |  |  |  |  |  |  |  | 3,399,724 |  |  |  |
US Treasury Securities [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Securities, Trading |  |  |  |  |  |  | $ 25,359,574 |  |  |  |  | $ 25,359,574 |  |  |

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- Definition Represents the price per share of the backstop agreed to be provided to the acquiree in a business combination. + References No definition available. + Details
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- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the cost method of accounting. + References No definition available. + Details
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- Definition This item represents the carrying amount, per share, on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References No definition available. + Details
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- Definition Number of shares of equity interests issued or issuable to acquire entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479581/805-30-50-1 + Details
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- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479328/805-10-50-2 + Details
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- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 30 -Paragraph 8 -SubTopic 30 -Topic 805 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479637/805-30-30-8 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -SubTopic 30 -Topic 805 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479581/805-30-50-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 30 -Paragraph 7 -SubTopic 30 -Topic 805 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479637/805-30-30-7 + Details
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- Definition Percentage of equity in the acquiree held by the acquirer immediately before the acquisition date in a business combination. + References No definition available. + Details
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- Definition In a business combination achieved in stages, this element represents the amount of gain recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (g)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479328/805-10-50-2 + Details
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- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-3 + Details
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- Definition Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares. + References No definition available. + Details
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- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-3 + Details
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- Definition The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482913/230-10-50-3 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482913/230-10-50-5 + Details
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- Definition Amount of gain (loss) from deconsolidation of subsidiary and derecognition of group of assets constituting transfer of business or nonprofit activity, excluding conveyance of oil and gas mineral rights and transfer of good or service in contract with customer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481203/810-10-50-1B + Details
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- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 + Details
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- Definition This item represents the aggregate value of each identified investment accounted for under the equity method of accounting based on the quoted market price for those investments in common stock for which a quoted market price is available. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 + Details
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- Definition The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 8A -Publisher FASB -URI https://asc.fasb.org//1943274/2147481830/320-10-45-8A + Details
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- Definition Number of shares of investment owned. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480524/946-210-50-6 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 55 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480493/946-210-55-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480524/946-210-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-6 + Details
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- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479581/805-30-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-13 + Details
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- Definition The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-13 + Details
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