Securities (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014 Institutions Tranche	Mar. 31, 2013	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Net gain recognized on sale of securities held to maturity		$ 169
Carrying value of securities held to maturity		4,292
Amortized Cost	572,100		513,594
Securities available for sale, at fair value	564,278		501,254
Number of institutions issuing debt (institutions)	340
Number of securities representing interests in tranches of trusts (tranches)	4
Secure government, public and trust deposits
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities pledged as collateral	748,738		604,571
Short-term borrowings
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities pledged as collateral	$ 4,991		$ 7,626

Number of institutions issuing debt.

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Number of securities representing interests in tranches of trusts.

+ References

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

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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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The fair value of available-for-sale securities that serve as collateral for borrowings.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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For any sales of securities categorized as held-to-maturity, this item represents the net carrying amount of the sold security.

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This item represents the gain (loss) realized on the sale of held-to-maturity securities disposed of during the period. Additionally, this item may include, if not separately presented, any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt securities which are being or have been recognized in earnings during the period.

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