Note 3 - Securities - Expected Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amounts maturing in:
Available-for-sale securities, amortized cost, one year or less	$ 1,550
Available-for-sale securities, fair value, one year or less	1,554
Available-for-sale securities, amortized cost, after one year through five years	79,378
Available-for-sale securities, fair value, after one year through five years	77,506
Available-for-sale securities, amortized cost, after five years through ten years	91,285
Available-for-sale securities, fair value, after five years through ten years	88,761
Available-for-sale securities, amortized cost, after ten years	73,211
Available-for-sale securities, fair value, after ten years	71,812
Available-for-sale securities, amortized cost, total	245,424	$ 268,407
Available-for-sale securities, fair value, total	$ 239,633

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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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth fiscal year through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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