Note 3 - Securities - Schedule of Securities in Unrealized Loss Positions (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Securities available for sale, fair value, less than 12 months	$ 70,400	$ 170,520
Securities available for sale, accumulated loss, less than 12 months	(1,614)	(7,987)
Securities available for sale, fair value, more than 12 months	1,019,106	1,034,046
Securities available for sale, accumulated loss, more than 12 months	(198,153)	(237,726)
Securities available for sale, fair value	1,089,506	1,204,566
Securities available for sale, accumulated loss	(199,767)	(245,713)
US Treasury and Government [Member]
Securities available for sale, fair value, less than 12 months	1,060	4,592
Securities available for sale, accumulated loss, less than 12 months	(3)	(320)
Securities available for sale, fair value, more than 12 months	92,690	110,515
Securities available for sale, accumulated loss, more than 12 months	(10,234)	(16,865)
Securities available for sale, fair value	93,750	115,107
Securities available for sale, accumulated loss	(10,237)	(17,185)
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, fair value, less than 12 months	21,246	66,436
Securities available for sale, accumulated loss, less than 12 months	(1,249)	(4,946)
Securities available for sale, fair value, more than 12 months	420,822	400,911
Securities available for sale, accumulated loss, more than 12 months	(95,200)	(101,418)
Securities available for sale, fair value	442,068	467,347
Securities available for sale, accumulated loss	(96,449)	(106,364)
Corporate Debt Securities [Member]
Securities available for sale, fair value, less than 12 months	4,247	4,303
Securities available for sale, accumulated loss, less than 12 months	(38)	(146)
Securities available for sale, fair value, more than 12 months	8,029	8,568
Securities available for sale, accumulated loss, more than 12 months	(332)	(427)
Securities available for sale, fair value	12,276	12,871
Securities available for sale, accumulated loss	(370)	(573)
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, fair value, less than 12 months	862	30,143
Securities available for sale, accumulated loss, less than 12 months	(23)	(365)
Securities available for sale, fair value, more than 12 months	444,752	460,172
Securities available for sale, accumulated loss, more than 12 months	(87,055)	(112,152)
Securities available for sale, fair value	445,614	490,315
Securities available for sale, accumulated loss	(87,078)	(112,517)
Collateralized Mortgage Obligations [Member]
Securities available for sale, fair value, less than 12 months	42,985	65,046
Securities available for sale, accumulated loss, less than 12 months	(301)	(2,210)
Securities available for sale, fair value, more than 12 months	50,675	51,405
Securities available for sale, accumulated loss, more than 12 months	(5,167)	(6,624)
Securities available for sale, fair value	93,660	116,451
Securities available for sale, accumulated loss	(5,468)	(8,834)
Small Business Administration [Member]
Securities available for sale, fair value, less than 12 months	0	0
Securities available for sale, accumulated loss, less than 12 months	0	0
Securities available for sale, fair value, more than 12 months	2,138	2,475
Securities available for sale, accumulated loss, more than 12 months	(165)	(240)
Securities available for sale, fair value	2,138	2,475
Securities available for sale, accumulated loss	$ (165)	$ (240)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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