Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	$ 261,249	$ 288,792
Investment securities available for sale, gross unrealized gains	2,822	1,399
Investment securities available for sale, gross unrealized losses	(3,802)	(5,396)
Investment securities available for sale, at fair value	260,269	284,795
Investment securities held to maturity, at amortized cost	178,628	172,277
Investment securities held to maturity, gross unrealized gains	2,844	441
Investment securities held to maturity, gross unrealized losses	(166)	(873)
Investment securities held to maturity, at fair value	181,306	171,845
Collateralized Mortgage Obligations [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	153,524	180,795
Investment securities available for sale, gross unrealized gains	1,897	523
Investment securities available for sale, gross unrealized losses	(324)	(3,173)
Investment securities available for sale, at fair value	155,097	178,145
Investment securities held to maturity, at amortized cost	142,760	146,458
Investment securities held to maturity, gross unrealized gains	2,562	402
Investment securities held to maturity, gross unrealized losses	(155)	(780)
Investment securities held to maturity, at fair value	145,167	146,080
Collateralized Mortgage Backed Securities [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	9,932	10,073
Investment securities available for sale, gross unrealized gains	52	176
Investment securities available for sale, gross unrealized losses	(22)	(78)
Investment securities available for sale, at fair value	9,962	10,171
Investment securities held to maturity, at amortized cost	18,043	7,732
Investment securities held to maturity, gross unrealized gains	127	0
Investment securities held to maturity, gross unrealized losses	0	(21)
Investment securities held to maturity, at fair value	18,170	7,711
US States and Political Subdivisions Debt Securities [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	22,903	22,814
Investment securities available for sale, gross unrealized gains	764	562
Investment securities available for sale, gross unrealized losses	(9)	(32)
Investment securities available for sale, at fair value	23,658	23,344
Corporate Debt Securities [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	54,275	54,294
Investment securities available for sale, gross unrealized gains	107	135
Investment securities available for sale, gross unrealized losses	(1,604)	(300)
Investment securities available for sale, at fair value	52,778	54,129
Asset-backed Securities [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	17,431	17,631
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(632)	(626)
Investment securities available for sale, at fair value	16,799	17,005
Collateralized Debt Obligations [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	3,069	3,070
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(1,211)	(1,187)
Investment securities available for sale, at fair value	1,858	1,883
Other Debt Obligations [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities available for sale, at amortized cost	115	115
Investment securities available for sale, gross unrealized gains	2	3
Investment securities available for sale, gross unrealized losses	0	0
Investment securities available for sale, at fair value	117	118
Investment securities held to maturity, at amortized cost	1,020	1,020
Investment securities held to maturity, gross unrealized gains	0	0
Investment securities held to maturity, gross unrealized losses	0	0
Investment securities held to maturity, at fair value	1,020	1,020
US Government Agencies Debt Securities [Member]
Note 5 - Investment Securities (Details) - Unrealized Gain (Loss) on Investments [Line Items]
Investment securities held to maturity, at amortized cost	16,805	17,067
Investment securities held to maturity, gross unrealized gains	155	39
Investment securities held to maturity, gross unrealized losses	(11)	(72)
Investment securities held to maturity, at fair value	$ 16,949	$ 17,034

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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