Note 3 - Investment Securities - Schedule of Available for Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Amortized Cost	$ 768,654	$ 754,425
Gross Unrealized Gains	344	136
Gross Unrealized Losses	(105,495)	(81,148)
Debt Securities, Available-for-Sale	663,503	673,413
US States and Political Subdivisions Debt Securities [Member]
Amortized Cost	158,803	321,700
Gross Unrealized Gains	4	136
Gross Unrealized Losses	(26,212)	(16,589)
Debt Securities, Available-for-Sale	132,595	305,247
Passthrough Mortgage Securities [Member]
Amortized Cost	169,593	179,655
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(36,561)	(31,135)
Debt Securities, Available-for-Sale	133,032	148,520
Collateralized Debt Obligations [Member]
Amortized Cost	190,836	134,070
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(26,924)	(20,676)
Debt Securities, Available-for-Sale	163,912	113,394
Corporate Bond Securities [Member]
Amortized Cost	119,000	119,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(14,755)	(12,748)
Debt Securities, Available-for-Sale	104,245	$ 106,252
Company Agency Obligations [Member]
Amortized Cost	130,422
Gross Unrealized Gains	340
Gross Unrealized Losses	(1,043)
Debt Securities, Available-for-Sale	$ 129,719

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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Amount, before tax, of unrealized loss 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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