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Note 13 - Benefit Plans (Details Textual) - USD ($) $ in Millions | 12 Months Ended | 69 Months Ended
--- | --- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2023
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay |  |  |  | 5.00%
Defined Contribution Plan, Cost | $ 2.3 | $ 2.2 | $ 2.1 |
Interest Expense, Deferred Compensation Plan | $ 0.1 | $ 0.1 | $ 0.1 |
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares) | 1,410 | 1,388 | 1,481 |
Common Stock Including Additional Paid in Capital [Member] |  |  |  |
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares) | 1,410 | 1,388 |  |
Stock Purchase Plan [Member] |  |  |  |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) | 250,000 |  |  | 250,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | 234,500 |  |  | 234,500
Other Liabilities [Member] |  |  |  |
Deferred Compensation Liability, Current and Noncurrent | $ 1.1 | $ 1.1 |  | $ 1.1

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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
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- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 70 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480794/715-70-50-1 + 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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