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Note 13 - Stock-based Compensation (Details Textual) - The 2018 Equity Incentive Plan [Member] - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Mar. 31, 2023 | May 17, 2018
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  |  | 1,300,000
Share-Based Payment Arrangement, Expense | $ 395,000 | $ 654,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expected Contractual Term Forfeiture Rate | 3.10% |  |
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 |  |
Share-Based Payment Arrangement, Tranche Four [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 |  |
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) | 80,622 |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) | 3 years 1 month 6 days |  |
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount | $ 2,200,000 |  |
Restricted Stock [Member] | Director [Member] | Minimum [Member] |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) | 1 year |  |
Restricted Stock [Member] | Officers And Employees [Member] | Maximum [Member] |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) | 5 years |  |
Share-Based Payment Arrangement, Option [Member] |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | 265,532 |  |
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 | $ 1,500,000 |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) | 3 years 2 months 12 days |  |
Share-Based Payment Arrangement, Option [Member] | Maximum [Member] |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) | 10 years |  |
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 |  |
Share-Based Payment Arrangement, Option [Member] | Officers And Employees [Member] | Share-Based Payment Arrangement, Tranche One [Member] |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 20.00% |  |
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 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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