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Note 8 - Stock-based Compensation (Tables) | 9 Months Ended
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Sep. 30, 2025
Notes Tables |
Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] |
|  |  |  |  |  | Weighted |
|  |  |  |  |  | Average |
|  | Shares |  |  | Fair Value |
Nonvested at beginning of the period |  |  | 228,646 |  |  | $ | 35.84 |
Grants |  |  | 84,685 |  |  |  | 50.34 |
Vested |  |  | (34,053 | ) |  |  | 34.79 |
Forfeited |  |  | (2,350 | ) |  |  | 42.24 |
Nonvested at end of the period |  |  | 276,928 |  |  | $ | 40.54 |
Corporate and Bank Board Members [Member] |
Notes Tables |
Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block] |
|  |  |  |  |  | Total Cost |  |
Grant Year |  | Shares Granted |  |  | (in thousands) |  | Covered Period
2023 |  |  | 11,529 |  |  | $ | 350 |  | June 1, 2023 - May 31, 2024
2024 |  |  | 11,316 |  |  |  | 423 |  | June 1, 2024 - May 31, 2025
2025 |  |  | 10,007 |  |  |  | 444 |  | June 1, 2025 - May 31, 2026

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