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Note 3 - Securities - Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Securities available for sale, amortized cost | $ 1,497,403 | $ 1,510,681
Securities available for sale, unrealized gains | 4,130 | 1,585
Securities available for sale, unrealized losses | (199,767) | (245,713)
Securities available for sale, fair value | 1,301,766 | 1,266,553
US Treasury and Government [Member] |  |
Securities available for sale, amortized cost | 105,155 | 132,292
Securities available for sale, unrealized gains | 34 | 0
Securities available for sale, unrealized losses | (10,237) | (17,185)
Securities available for sale, fair value | 94,952 | 115,107
US States and Political Subdivisions Debt Securities [Member] |  |
Securities available for sale, amortized cost | 590,327 | 609,950
Securities available for sale, unrealized gains | 1,916 | 1,294
Securities available for sale, unrealized losses | (96,449) | (106,364)
Securities available for sale, fair value | 495,794 | 504,880
Corporate Debt Securities [Member] |  |
Securities available for sale, amortized cost | 16,674 | 17,849
Securities available for sale, unrealized gains | 167 | 172
Securities available for sale, unrealized losses | (370) | (573)
Securities available for sale, fair value | 16,471 | 17,448
Collateralized Mortgage-Backed Securities [Member] |  |
Securities available for sale, amortized cost | 622,160 | 605,350
Securities available for sale, unrealized gains | 677 | 34
Securities available for sale, unrealized losses | (87,078) | (112,517)
Securities available for sale, fair value | 535,759 | 492,867
Collateralized Mortgage Obligations [Member] |  |
Securities available for sale, amortized cost | 160,784 | 142,525
Securities available for sale, unrealized gains | 1,336 | 85
Securities available for sale, unrealized losses | (5,468) | (8,834)
Securities available for sale, fair value | 156,652 | 133,776
Small Business Administration [Member] |  |
Securities available for sale, amortized cost | 2,303 | 2,715
Securities available for sale, unrealized gains | 0 | 0
Securities available for sale, unrealized losses | (165) | (240)
Securities available for sale, fair value | $ 2,138 | $ 2,475

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