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Note 11 - Stock-based Compensation (Details Textual) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | May 17, 2018
Share-Based Payment Arrangement, Expense | $ 583,000 | $ 464,000 | $ 1,600,000 | $ 1,200,000 |  |
Share-Based Payment Arrangement, Option [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 6 years 2 months 12 days |  | 6 years 3 months 18 days |
The 2018 Equity Incentive Plan [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  |  |  |  |  | 1,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expected Contractual Term Forfeiture Rate |  |  | 3.10% |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche One [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 1 year |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 5 years 6 months |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche Two [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 4 years |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 6 years 3 months |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Tranche Three [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 5 years |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term (Year) |  |  | 6 years 6 months |  |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  |  |  |  |  | 326,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | 500 |  | 500 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | $ 3,700,000 |  | $ 3,700,000 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  | 2 years |  |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Officers And Employees [Member] | Minimum [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 4 years |  |  |
The 2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Officers And Employees [Member] | Maximum [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 5 years |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | 52,060 |  | 52,060 |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) |  |  | 10 years |  |  |
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | $ 3,100,000 |  | $ 3,100,000 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  |  | 2 years |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Maximum [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) |  |  | 10 years |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Director [Member] | Minimum [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 1 year |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Officers And Employees [Member] | Minimum [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 4 years |  |  |
The 2018 Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Officers And Employees [Member] | Maximum [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  |  | 5 years |  |  |

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- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -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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