Note 4 - Debt Securities Available-for-Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	$ 490,182	$ 546,525
Investment securities available-for-sale, debt securities gross unrealized holding gains	5	2
Investment securities available-for-sale, debt securities gross unrealized holding losses	(84,252)	(102,694)
Investment securities available-for-sale, debt securities gross unrealized fair value hedge gains	(1,749)
Investment securities available-for-sale, debt securities amortized cost	576,178	649,217
US Treasury Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	6,451	301
Investment securities available-for-sale, debt securities gross unrealized holding gains	3	2
Investment securities available-for-sale, debt securities amortized cost	6,448	299
US Government Agencies Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	74,122	86,709
Investment securities available-for-sale, debt securities gross unrealized holding losses	(10,828)	(15,233)
Investment securities available-for-sale, debt securities amortized cost	84,950	101,942
US States and Political Subdivisions Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	89,189	95,367
Investment securities available-for-sale, debt securities gross unrealized holding losses	(18,714)	(23,494)
Investment securities available-for-sale, debt securities gross unrealized fair value hedge gains	(445)
Investment securities available-for-sale, debt securities amortized cost	108,348	118,861
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	224,238	256,161
Investment securities available-for-sale, debt securities gross unrealized holding losses	(37,831)	(45,303)
Investment securities available-for-sale, debt securities gross unrealized fair value hedge gains	(1,304)
Investment securities available-for-sale, debt securities amortized cost	263,373	301,464
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	89,973	101,672
Investment securities available-for-sale, debt securities gross unrealized holding losses	(16,383)	(18,338)
Investment securities available-for-sale, debt securities amortized cost	106,356	120,010
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities		6,315
Investment securities available-for-sale, debt securities gross unrealized holding losses		(326)
Investment securities available-for-sale, debt securities amortized cost		$ 6,641
Corporate Debt Securities and Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	6,209
Investment securities available-for-sale, debt securities gross unrealized holding gains	2
Investment securities available-for-sale, debt securities gross unrealized holding losses	(496)
Investment securities available-for-sale, debt securities amortized cost	$ 6,703

Available for sale debt securities accumulated gross unrealized fair value hedge gain before tax.

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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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