Note 3 - Securities - Securities Available-for-sale (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Securities available-for-sale, amortized costs	$ 739,265	$ 759,917
Securities available-for-sale, gross unrealized gains	3	87
Securities available-for-sale, gross unrealized losses	88,221	103,152
Securities available for sale, allowance for credit loss	0
Securities available for sale	651,047	656,852
US Treasury Securities [Member]
Securities available-for-sale, amortized costs	993	992
Securities available-for-sale, gross unrealized gains	0	0
Securities available-for-sale, gross unrealized losses	46	56
Securities available for sale, allowance for credit loss	0
Securities available for sale	947	936
US Government Agencies Debt Securities [Member]
Securities available-for-sale, amortized costs	382,592	391,538
Securities available-for-sale, gross unrealized gains	0	39
Securities available-for-sale, gross unrealized losses	48,648	55,002
Securities available for sale, allowance for credit loss	0
Securities available for sale	333,944	336,575
US States and Political Subdivisions Debt Securities [Member]
Securities available-for-sale, amortized costs	181,214	190,192
Securities available-for-sale, gross unrealized gains	3	26
Securities available-for-sale, gross unrealized losses	31,255	38,018
Securities available for sale, allowance for credit loss	0
Securities available for sale	149,962	152,200
Collateralized Mortgage-Backed Securities [Member]
Securities available-for-sale, amortized costs	167,964	170,694
Securities available-for-sale, gross unrealized gains	0	22
Securities available-for-sale, gross unrealized losses	7,511	9,239
Securities available for sale, allowance for credit loss	0
Securities available for sale	160,453	161,477
Corporate Debt Securities [Member]
Securities available-for-sale, amortized costs	6,502	6,501
Securities available-for-sale, gross unrealized gains	0	0
Securities available-for-sale, gross unrealized losses	761	837
Securities available for sale, allowance for credit loss	0
Securities available for sale	$ 5,741	$ 5,664

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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Amortized cost of 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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