Note 4 - Securities - Securities Available-for-sale (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Securities available-for-sale, amortized costs	$ 345,260	$ 336,075
Securities available-for-sale, gross unrealized gains	554	954
Securities available-for-sale, gross unrealized losses	8,603	5,642
Securities available-for-sale, fair values	337,211	331,387
US Government Agencies Debt Securities [Member]
Securities available-for-sale, amortized costs	322,585	312,604
Securities available-for-sale, gross unrealized gains	393	609
Securities available-for-sale, gross unrealized losses	8,089	5,494
Securities available-for-sale, fair values	314,889	307,719
US States and Political Subdivisions Debt Securities [Member]
Securities available-for-sale, amortized costs	16,101	16,853
Securities available-for-sale, gross unrealized gains	69	100
Securities available-for-sale, gross unrealized losses	392	119
Securities available-for-sale, fair values	15,778	16,834
Collateralized Mortgage Backed Securities [Member]
Securities available-for-sale, amortized costs	558	602
Securities available-for-sale, gross unrealized gains	50	57
Securities available-for-sale, gross unrealized losses	0	0
Securities available-for-sale, fair values	608	659
Corporate Debt Securities [Member]
Securities available-for-sale, amortized costs	6,016	6,016
Securities available-for-sale, gross unrealized gains	42	188
Securities available-for-sale, gross unrealized losses	122	29
Securities available-for-sale, fair values	$ 5,936	$ 6,175

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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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-SubTopic 10
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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).

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-Publisher FASB
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-Name Accounting Standards Codification
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