Note 4 - Investment Securities (Details) - Investment Securities Available-for-sale (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	$ 375,219,000us-gaap_AvailableForSaleSecurities	$ 388,670,000us-gaap_AvailableForSaleSecurities
Investment securities available-for-sale, gross unrealized holding gains	5,073,000	4,446,000
Investment securities available-for-sale, gross unrealized holding losses	(3,698,000)	(9,616,000)
Investment securities available-for-sale, amortized cost	373,844,000	393,840,000
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	62,665,000	71,639,000
Investment securities available-for-sale, gross unrealized holding gains	212,000	195,000
Investment securities available-for-sale, gross unrealized holding losses	(472,000)	(1,702,000)
Investment securities available-for-sale, amortized cost	62,925,000	73,146,000
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	72,569,000	87,199,000
Investment securities available-for-sale, gross unrealized holding gains	1,500,000	1,023,000
Investment securities available-for-sale, gross unrealized holding losses	(150,000)	(1,627,000)
Investment securities available-for-sale, amortized cost	71,219,000	87,803,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	136,192,000	139,723,000
Investment securities available-for-sale, gross unrealized holding gains	1,819,000	1,436,000
Investment securities available-for-sale, gross unrealized holding losses	(466,000)	(2,361,000)
Investment securities available-for-sale, amortized cost	134,839,000	140,648,000
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	87,662,000	75,394,000
Investment securities available-for-sale, gross unrealized holding gains	330,000	556,000
Investment securities available-for-sale, gross unrealized holding losses	(1,300,000)	(2,334,000)
Investment securities available-for-sale, amortized cost	88,632,000	77,172,000
Collateralized Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	2,439,000	2,069,000
Investment securities available-for-sale, gross unrealized holding gains	160,000	85,000
Investment securities available-for-sale, gross unrealized holding losses	(1,240,000)	(1,535,000)
Investment securities available-for-sale, amortized cost	3,519,000	3,519,000
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	6,037,000	6,021,000
Investment securities available-for-sale, gross unrealized holding gains	30,000	24,000
Investment securities available-for-sale, gross unrealized holding losses		(13,000)
Investment securities available-for-sale, amortized cost	6,007,000	6,010,000
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities available-for-sale	7,655,000	6,625,000
Investment securities available-for-sale, gross unrealized holding gains	1,022,000	1,127,000
Investment securities available-for-sale, gross unrealized holding losses	(70,000)	(44,000)
Investment securities available-for-sale, amortized cost	$ 6,703,000	$ 5,542,000

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

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