Note 6 - Available-for-Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	$ 609,567	$ 692,360
Investment securities available-for-sale, debt securities gross unrealized holding gains	67	3,568
Investment securities available-for-sale, debt securities gross unrealized holding losses	(77,904)	(8,302)
Investment securities available-for-sale, debt securities amortized cost	687,404	697,094
US Treasury Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	893
Investment securities available-for-sale, debt securities gross unrealized holding losses	(2)
Investment securities available-for-sale, debt securities amortized cost	895
US Government Agencies Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	91,090	97,499
Investment securities available-for-sale, debt securities gross unrealized holding gains		2
Investment securities available-for-sale, debt securities gross unrealized holding losses	(10,847)	(2,435)
Investment securities available-for-sale, debt securities amortized cost	101,937	99,932
US States and Political Subdivisions Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	108,495	131,035
Investment securities available-for-sale, debt securities gross unrealized holding gains	28	1,716
Investment securities available-for-sale, debt securities gross unrealized holding losses	(21,058)	(1,053)
Investment securities available-for-sale, debt securities amortized cost	129,525	130,372
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	285,320	329,938
Investment securities available-for-sale, debt securities gross unrealized holding gains	7	1,273
Investment securities available-for-sale, debt securities gross unrealized holding losses	(34,127)	(3,158)
Investment securities available-for-sale, debt securities amortized cost	319,440	331,823
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	117,277	127,012
Investment securities available-for-sale, debt securities gross unrealized holding gains	2	398
Investment securities available-for-sale, debt securities gross unrealized holding losses	(11,669)	(1,648)
Investment securities available-for-sale, debt securities amortized cost	128,944	128,262
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, debt securities	6,492	6,876
Investment securities available-for-sale, debt securities gross unrealized holding gains	30	179
Investment securities available-for-sale, debt securities gross unrealized holding losses	(201)	(8)
Investment securities available-for-sale, debt securities amortized cost	$ 6,663	$ 6,705

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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