Note 6 - Available-for-Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	$ 481,596	$ 490,182
Investment securities available-for-sale, debt securities gross unrealized holding gains	10	5
Investment securities available-for-sale, debt securities gross unrealized holding losses	(88,723)	(84,252)
Investment securities available-for-sale, debt securities gross unrealized fair value hedge gains (losses)	4,445	(1,749)
Investment securities available-for-sale, debt securities amortized cost	565,864	576,178
US Treasury Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	5,455	6,451
Investment securities available-for-sale, debt securities gross unrealized holding gains		3
Investment securities available-for-sale, debt securities gross unrealized holding losses	(1)
Investment securities available-for-sale, debt securities amortized cost	5,456	6,448
US Government Agencies Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	73,529	74,122
Investment securities available-for-sale, debt securities gross unrealized holding losses	(11,423)	(10,828)
Investment securities available-for-sale, debt securities amortized cost	84,952	84,950
US States and Political Subdivisions Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	89,554	89,189
Investment securities available-for-sale, debt securities gross unrealized holding losses	(19,816)	(18,714)
Investment securities available-for-sale, debt securities gross unrealized fair value hedge gains (losses)	1,299	(445)
Investment securities available-for-sale, debt securities amortized cost	108,071	108,348
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	220,271	224,238
Investment securities available-for-sale, debt securities gross unrealized holding losses	(40,093)	(37,831)
Investment securities available-for-sale, debt securities gross unrealized fair value hedge gains (losses)	3,146	(1,304)
Investment securities available-for-sale, debt securities amortized cost	257,218	263,373
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	86,564	89,973
Investment securities available-for-sale, debt securities gross unrealized holding losses	(16,893)	(16,383)
Investment securities available-for-sale, debt securities amortized cost	103,457	106,356
Corporate Debt Securities and Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	6,223	6,209
Investment securities available-for-sale, debt securities gross unrealized holding gains	10	2
Investment securities available-for-sale, debt securities gross unrealized holding losses	(497)	(496)
Investment securities available-for-sale, debt securities amortized cost	$ 6,710	$ 6,703

Available for sale debt securities accumulated gross unrealized fair value hedge gain (loss) 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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