Note 3 - Securities Available for Sale - Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Securities available for sale, amortized cost	$ 1,659,271	$ 1,525,224
Securities available for sale, unrealized gains	3,724	5,032
Securities available for sale, unrealized losses	(189,297)	(186,799)
Securities available for sale, fair value	1,473,698	1,343,457
US Treasury and Government [Member]
Securities available for sale, amortized cost	104,704	104,737
Securities available for sale, unrealized gains	19	45
Securities available for sale, unrealized losses	(10,213)	(9,487)
Securities available for sale, fair value	94,510	95,295
US States and Political Subdivisions Debt Securities [Member]
Securities available for sale, amortized cost	714,596	589,236
Securities available for sale, unrealized gains	2,962	2,632
Securities available for sale, unrealized losses	(87,139)	(88,171)
Securities available for sale, fair value	630,419	503,697
Corporate Debt Securities [Member]
Securities available for sale, amortized cost	27,820	13,171
Securities available for sale, unrealized gains	246	163
Securities available for sale, unrealized losses	(471)	(289)
Securities available for sale, fair value	27,595	13,045
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, amortized cost	631,434	629,376
Securities available for sale, unrealized gains	196	731
Securities available for sale, unrealized losses	(83,977)	(82,973)
Securities available for sale, fair value	547,653	547,134
Collateralized Mortgage Obligations [Member]
Securities available for sale, amortized cost	178,792	186,494
Securities available for sale, unrealized gains	301	1,461
Securities available for sale, unrealized losses	(7,361)	(5,739)
Securities available for sale, fair value	171,732	182,216
Small Business Administration [Member]
Securities available for sale, amortized cost	1,925	2,210
Securities available for sale, unrealized gains	0	0
Securities available for sale, unrealized losses	(136)	(140)
Securities available for sale, fair value	$ 1,789	$ 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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