Note 6 - Securities - Securities Available-for-sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale, Amortized Cost	$ 963,978	$ 985,599
Gross unrealized gains	1,274	303
Gross unrealized losses	85,681	95,151
Securities, fair value	879,571	890,751
US Treasury Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	17,690	32,783
Gross unrealized gains	0	0
Gross unrealized losses	1,451	2,668
Securities, fair value	16,239	30,115
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	10,258	50,288
Gross unrealized gains	0	0
Gross unrealized losses	848	2,916
Securities, fair value	9,410	47,372
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	49,609	48,475
Gross unrealized gains	0	25
Gross unrealized losses	5,770	2,496
Securities, fair value	43,839	46,004
Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	555,148	506,671
Gross unrealized gains	976	267
Gross unrealized losses	49,814	55,213
Securities, fair value	506,310	451,725
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-Sale, Amortized Cost	331,273	347,382
Gross unrealized gains	298	11
Gross unrealized losses	27,798	31,858
Securities, fair value	$ 303,773	$ 315,535

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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-Topic 320
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+ References

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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