Note 4 - Securities - Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Amortized cost, due in one year or less, available for sale securities	$ 62,607
Fair value, due in one year or less, available for sale securities	62,459
Amortized cost, due after one year through five years, available for sale securities	174,190
Fair value, due after one year through five years, available for sale securities	172,334
Amortized cost, due after five years through ten years, available for sale securities	82,061
Fair value, due after five years through ten years, available for sale securities	82,551
Amortized cost, due after ten years, available for sale securities	86,455
Fair value, due after ten years, available for sale securities	87,301
Amortized cost, total securities available for sale	405,313	$ 431,428
Fair value, total securities available for sale	$ 404,645	$ 425,010

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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