Note 3 - Securities - Expected Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Amounts maturing in:
Available-for-sale securities, amortized cost, one year or less	$ 1,509
Available-for-sale securities, fair value, one year or less	1,511
Available-for-sale securities, amortized cost, after one year through five years	74,398
Available-for-sale securities, fair value, after one year through five years	72,826
Available-for-sale securities, amortized cost, after five years through ten years	95,363
Available-for-sale securities, fair value, after five years through ten years	93,157
Available-for-sale securities, amortized cost, after ten years	81,252
Available-for-sale securities, fair value, after ten years	80,145
Available-for-sale securities, amortized cost, total	252,522	$ 268,406
Available-for-sale securities, fair value, total	$ 247,639

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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