Note 3 - Securities Available for Sale - Schedule of Securities in Unrealized Loss Positions (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Securities available for sale, fair value, less than 12 months	$ 569,756	$ 109,216
Securities available for sale, accumulated loss, less than 12 months	(46,441)	(2,338)
Securities available for sale, fair value, more than 12 months	820,880	1,040,492
Securities available for sale, accumulated loss, more than 12 months	(230,554)	(184,461)
Securities available for sale, fair value	1,390,636	1,149,708
Securities available for sale, accumulated loss	(276,995)	(186,799)
US Treasury and Government [Member]
Securities available for sale, fair value, less than 12 months	1,952	100
Securities available for sale, accumulated loss, less than 12 months	(115)	0
Securities available for sale, fair value, more than 12 months	1,973	93,211
Securities available for sale, accumulated loss, more than 12 months	(352)	(9,487)
Securities available for sale, fair value	3,925	93,311
Securities available for sale, accumulated loss	(467)	(9,487)
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, fair value, less than 12 months	198,399	6,302
Securities available for sale, accumulated loss, less than 12 months	(21,431)	(1,360)
Securities available for sale, fair value, more than 12 months	367,200	432,053
Securities available for sale, accumulated loss, more than 12 months	(120,719)	(86,811)
Securities available for sale, fair value	565,599	438,355
Securities available for sale, accumulated loss	(142,150)	(88,171)
Corporate Debt Securities [Member]
Securities available for sale, fair value, less than 12 months	16,184	2,962
Securities available for sale, accumulated loss, less than 12 months	(389)	(44)
Securities available for sale, fair value, more than 12 months	5,411	6,293
Securities available for sale, accumulated loss, more than 12 months	(198)	(245)
Securities available for sale, fair value	21,595	9,255
Securities available for sale, accumulated loss	(587)	(289)
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, fair value, less than 12 months	188,976	48,965
Securities available for sale, accumulated loss, less than 12 months	(13,280)	(313)
Securities available for sale, fair value, more than 12 months	375,136	437,859
Securities available for sale, accumulated loss, more than 12 months	(102,124)	(82,660)
Securities available for sale, fair value	564,112	486,824
Securities available for sale, accumulated loss	(115,404)	(82,973)
Collateralized Mortgage Obligations [Member]
Securities available for sale, fair value, less than 12 months	164,245	50,887
Securities available for sale, accumulated loss, less than 12 months	(11,226)	(621)
Securities available for sale, fair value, more than 12 months	69,549	69,006
Securities available for sale, accumulated loss, more than 12 months	(6,997)	(5,118)
Securities available for sale, fair value	233,794	119,893
Securities available for sale, accumulated loss	(18,223)	(5,739)
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	1,611	2,070
Securities available for sale, accumulated loss, more than 12 months	(164)	(140)
Securities available for sale, fair value	1,611	2,070
Securities available for sale, accumulated loss	$ (164)	$ (140)

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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