Note 4 - Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized cost, due in one year or less, available for sale securities	$ 9,684
Fair value, due in one year or less, available for sale securities	9,766
Amortized cost, due after one year through five years, available for sale securities	4,479
Fair value, due after one year through five years, available for sale securities	4,635
Amortized cost, due after five years through ten years, available for sale securities	135,247
Fair value, due after five years through ten years, available for sale securities	139,803
Amortized cost, due after ten years, available for sale securities	328,468
Fair value, due after ten years, available for sale securities	335,722
Amortized cost, total securities available for sale	477,878	$ 435,166
Fair value, total securities available for sale	$ 489,926	$ 435,263

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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