Note 7 - Stock-based Compensation - Stock Option Plan Cost (Details) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Fair value of options vested | $ 159,000 | $ 191,000 | $ 332,000 | $ 384,000 |
| Intrinsic value of options exercised | 131,000 | 260,000 | 1,656,000 | 874,000 |
| Cash received from option exercises | 81,000 | 353,000 | 1,569,000 | 936,000 |
| Tax benefit from option exercises | 8,000 | 24,000 | 149,000 | 43,000 |
| Compensation cost | 138,000 | 93,000 | 389,000 | 256,000 |
| Tax benefit associated with compensation cost | $ 9,000 | $ 5,000 | $ 23,000 | $ 14,000 |
| X | ||||||||||
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of tax benefit for recognition of expense of award under share-based payment arrangement. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of tax benefit from exercise of option under share-based payment arrangement. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of cash inflow from exercise of option under share-based payment arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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