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Note 8 - Stock-based Incentive Plans (Details Textual) - USD ($) |  |  |  | 3 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Apr. 01, 2025 | Feb. 07, 2023 | Mar. 15, 2021 | Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024 | Dec. 31, 2023 | Mar. 31, 2025
Restricted Stock [Member] |  |  |  |  |  |  |  |  |
Share-Based Payment Arrangement, Expense |  |  |  | $ 34,000 | $ 38,000 | $ 68,000 | $ 75,000 |  |
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount |  |  |  | $ 63,000 |  | $ 63,000 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  |  | 3 months 18 days |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) |  |  |  |  |  | 14,356 |  |  |
Equity Incentive Plan 2016 [Member] |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) |  |  |  |  |  |  |  |  | 2,500,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) |  |  |  |  |  |  |  |  | 1,129,047
The Phantom Plan [Member] |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) |  |  | 10 years |  |  |  |  |  |
The Phantom Plan [Member] | Phantom Shares [Member] | Employees and Non-Employee Directors [Member] |  |  |  |  |  |  |  |  |
Share-Based Payment Arrangement, Expense |  |  |  |  | $ 181,000 | $ 0 | $ 181,000 |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares) | 223,307 | 212,937 |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Month) | 2 years |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Maximum Payment Per Share (in dollars per share) | $ 12 | $ 12 |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares) |  |  |  |  |  |  |  | 186,320 |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period (in shares) |  |  |  |  |  | 26,617 |  |  |
The Phantom Plan [Member] | Phantom Shares [Member] | Employees and Non-Employee Directors [Member] | Vesting Increments [Member] |  |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Month) |  | 3 months |  |  |  |  |  |  |
The Phantom Plan [Member] | Phantom Shares [Member] | Employees and Non-Employee Directors [Member] | Vesting Per Quarter [Member] |  |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 12.50% |  |  |  |  |  |  |  |
The Phantom Plan [Member] | Phantom Shares [Member] | Employees and Non-Employee Directors [Member] | Financial Results Based Award Vesting [Member] |  |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 6.25% |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Minimum Amount of Operating Profit Needed to Meet Service Condition | $ 150,000 |  |  |  |  |  |  |  |
The Phantom Plan [Member] | Phantom Shares [Member] | Employees and Non-Employee Directors [Member] | Stock Appreciation Based Award Vesting [Member] |  |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 6.25% |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Minimum Amount of Operating Profit Needed to Meet Service Condition | $ 150,000 |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Additional Financial Performance Condition Needed for Vesting Award | $ 300,000 |  |  |  |  |  |  |  |

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- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(03) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(02) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
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