Note 17 - Commitments and Credit Risk (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Letters of Credit Outstanding, Amount	$ 29,362,000	$ 23,515,000
Standby Letters of Credit [Member]
Deferred Revenue	$ 0	0
Minimum [Member]
Letters of Credit Term	270 days
Maximum [Member]
Letters of Credit Term	15 years
Maximum [Member] \| Bonds Issued by a Single Municipality as a Percentage of the Investment Portfolio [Member]
Concentration Risk, Percentage	5.00%
Credit Card Commitments to Extend Credit [Member]
Commitments and Contingencies	$ 562,527,000	497,961,000
Other Loan Commitments to Extend Credit [Member]
Commitments and Contingencies	$ 1,220,137,000	$ 805,673,000

Letters of credit term.

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- Definition

Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.(a),19)
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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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-Section 50
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- Definition

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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