Investment Securities (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Investment securities available for sale
Amortized Cost	$ 499,976	$ 520,826	$ 313,408
Gross Unrealized Gains	11,580	14,240	9,382
Gross Unrealized Losses	(704)	(183)	(202)
Fair Value	510,852	534,883	322,588
Government-sponsored entities debt
Investment securities available for sale
Amortized Cost	71,408	87,584	65,505
Gross Unrealized Gains	515	965	985
Gross Unrealized Losses	(121)	(31)	(112)
Fair Value	71,802	88,518	66,378
State and municipal obligations
Investment securities available for sale
Amortized Cost	144,979	147,201	39,099
Gross Unrealized Gains	4,308	5,647	2,942
Gross Unrealized Losses	(391)	(49)	(33)
Fair Value	148,896	152,799	42,008
Mortgage-backed securities
Investment securities available for sale
Amortized Cost	283,348	285,800	208,564
Gross Unrealized Gains	6,585	7,489	5,301
Gross Unrealized Losses	(191)	(102)	(56)
Fair Value	289,742	293,187	213,809
Corporate stocks
Investment securities available for sale
Amortized Cost	241	241	240
Gross Unrealized Gains	172	139	154
Gross Unrealized Losses	(1)	(1)	(1)
Fair Value	$ 412	$ 379	$ 393

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.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

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