Note 4 - Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Amortized cost, due in one year or less, available for sale securities	$ 1,864
Fair value, due in one year or less, available for sale securities	1,902
Amortized cost, due after one year through five years, available for sale securities	8,722
Fair value, due after one year through five years, available for sale securities	8,785
Amortized cost, due after five years through ten years, available for sale securities	264,217
Fair value, due after five years through ten years, available for sale securities	265,751
Amortized cost, due after ten years, available for sale securities	360,752
Fair value, due after ten years, available for sale securities	365,048
Amortized cost, total securities available for sale	635,555	$ 530,075
Fair value, total securities available for sale	$ 641,486	$ 546,742

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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