Note 6 - Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Due in one year or less, Fair value	$ 5,277
Due after one year through five years, Fair value	140,407
Due after five years through ten years, Fair value	417,401
Due after ten years, Fair value	93,761
Total investment securities available-for-sale, Fair value	656,846	$ 692,360
Due in one year or less, Amortized cost	5,260
Due after one year through five years, Amortized cost	146,514
Due after five years through ten years, Amortized cost	450,278
Due after ten years, Amortized cost	105,859
Investment securities available-for-sale, debt securities amortized cost	$ 707,911	$ 697,094

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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