Note 3 - Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2013	Dec. 31, 2012
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Pledged Financial Instruments, Not Separately Reported, Securities			$ 815,646	$ 850,421
Number Of Securities Transferred From Held To Maturity To Available For Sale	1
Held-to-maturity Securities, Transferred Security, at Carrying Value	9,077	9,077
Proceeds from Sale of Available-for-sale Securities, Debt	7,790
Available-for-sale Securities, Gross Realized Gain (Loss)	$ (1,287)	$ (1,287)

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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- Definition

For any transfer of securities categorized as held-to-maturity, this item represents the net carrying amount of the transferred security to another category of investments in debt and equity securities (trading or available-for-sale).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27405-111563

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- Definition

Sum of the carrying amounts as of the date of the latest financial statement presented of securities which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 50

-Paragraph 1A

-Subparagraph (b)(1)(i)

-URI http://asc.fasb.org/extlink&oid=7523297&loc=SL6224234-111729

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- Definition

The cash inflow associated with the sale of debt securities classified as available-for-sale securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26853-111562

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

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- Definition

Number Of Securities Transferred From Held To Maturity To Available For Sale

+ References

No definition available.

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