Note 3 - Securities Available for Sale - Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Securities available for sale, amortized cost	$ 1,680,390	$ 1,525,224
Securities available for sale, unrealized gains	136	5,032
Securities available for sale, unrealized losses	(276,995)	(186,799)
Securities available for sale, fair value	1,403,531	1,343,457
US Treasury and Government [Member]
Securities available for sale, amortized cost	4,392	104,737
Securities available for sale, unrealized gains	0	45
Securities available for sale, unrealized losses	(467)	(9,487)
Securities available for sale, fair value	3,925	95,295
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, amortized cost	714,400	589,236
Securities available for sale, unrealized gains	45	2,632
Securities available for sale, unrealized losses	(142,150)	(88,171)
Securities available for sale, fair value	572,295	503,697
Corporate Debt Securities [Member]
Securities available for sale, amortized cost	25,914	13,171
Securities available for sale, unrealized gains	76	163
Securities available for sale, unrealized losses	(587)	(289)
Securities available for sale, fair value	25,403	13,045
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, amortized cost	680,844	629,376
Securities available for sale, unrealized gains	5	731
Securities available for sale, unrealized losses	(115,404)	(82,973)
Securities available for sale, fair value	565,445	547,134
Collateralized Mortgage Obligations [Member]
Securities available for sale, amortized cost	253,065	186,494
Securities available for sale, unrealized gains	10	1,461
Securities available for sale, unrealized losses	(18,223)	(5,739)
Securities available for sale, fair value	234,852	182,216
Small Business Administration [Member]
Securities available for sale, amortized cost	1,775	2,210
Securities available for sale, unrealized gains	0	0
Securities available for sale, unrealized losses	(164)	(140)
Securities available for sale, fair value	$ 1,611	$ 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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