Note 6 - Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investments Debt And Equity Securities [Abstract]
Due in one year or less, Fair value	$ 329
Due after one year through five years, Fair value	114,266
Due after five years through ten years, Fair value	344,044
Due after ten years, Fair value	79,265
Investment debt securities available-for-sale, Fair value	537,904	$ 546,525
Due in one year or less, Amortized cost	338
Due after one year through five years, Amortized cost	126,292
Due after five years through ten years, Amortized cost	405,060
Due after ten years, Amortized cost	97,497
Investment securities available-for-sale, debt securities amortized cost	$ 629,187	$ 649,217

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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