Note 4 - Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Due in one year or less, Fair value	$ 2,837
Due after one year through five years, Fair value	326,734
Due after five years through ten years, Fair value	255,561
Due after ten years, Fair value	107,228
Total investment securities available-for-sale, Fair value	692,360	$ 435,646
Due in one year or less, Amortized cost	2,815
Due after one year through five years, Amortized cost	327,828
Due after five years through ten years, Amortized cost	259,246
Due after ten years, Amortized cost	107,205
Investment securities available-for-sale, debt securities amortized cost	$ 697,094	$ 428,495

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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