Note 3 - Securities Available for Sale - Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Securities available for sale, amortized cost	$ 1,673,903	$ 1,525,224
Securities available for sale, unrealized gains	3,106	5,032
Securities available for sale, unrealized losses	(192,811)	(186,799)
Securities available for sale, fair value	1,484,198	1,343,457
US Treasury and Government [Member]
Securities available for sale, amortized cost	104,720	104,737
Securities available for sale, unrealized gains	29	45
Securities available for sale, unrealized losses	(9,851)	(9,487)
Securities available for sale, fair value	94,898	95,295
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, amortized cost	716,934	589,236
Securities available for sale, unrealized gains	1,710	2,632
Securities available for sale, unrealized losses	(92,688)	(88,171)
Securities available for sale, fair value	625,956	503,697
Corporate Debt Securities [Member]
Securities available for sale, amortized cost	32,213	13,171
Securities available for sale, unrealized gains	140	163
Securities available for sale, unrealized losses	(280)	(289)
Securities available for sale, fair value	32,073	13,045
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, amortized cost	635,441	629,376
Securities available for sale, unrealized gains	610	731
Securities available for sale, unrealized losses	(83,320)	(82,973)
Securities available for sale, fair value	552,731	547,134
Collateralized Mortgage Obligations [Member]
Securities available for sale, amortized cost	182,586	186,494
Securities available for sale, unrealized gains	617	1,461
Securities available for sale, unrealized losses	(6,543)	(5,739)
Securities available for sale, fair value	176,660	182,216
Small Business Administration [Member]
Securities available for sale, amortized cost	2,009	2,210
Securities available for sale, unrealized gains	0	0
Securities available for sale, unrealized losses	(129)	(140)
Securities available for sale, fair value	$ 1,880	$ 2,070

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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