Note 8 - Income Taxes (Details) - Reconciliation of Income Tax Expense (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Note 8 - Income Taxes (Details) - Reconciliation of Income Tax Expense [Line Items]
Computed at the statutory rate (35%)	$ 17,601	$ 11,387	$ 14,012
Increase (decrease) in taxes resulting from:
State income taxes, net of federal tax benefit	41	825	1,142
Other differences, net	1,233	293	304
Actual tax provision	14,602us-gaap_IncomeTaxExpenseBenefit	9,305us-gaap_IncomeTaxExpenseBenefit	12,331us-gaap_IncomeTaxExpenseBenefit
Tax Exempt Interest Income [Member]
Increase (decrease) in taxes resulting from:
Tax exempt income	(3,774)	(2,739)	(2,615)
Tax Exempt Earnings on Bank Owned Life Insurance [Member]
Increase (decrease) in taxes resulting from:
Tax exempt earnings on BOLI	$ (499)	$ (461)	$ (512)

Income tax rate reconciliation on tax exempt interest income.

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Income tax rate reconciliation on cash value changes in bank owned life insurance.

+ References

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

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-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319

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-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319

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-Name Regulation S-X (SX)

-Number 210

-Section 08

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments.

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