Investment Portfolio (Details 1) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended	12 Months Ended
Jun. 30, 2012	Dec. 31, 2011
Available for sale Investments (substantially restricted)
Amortized cost	$ 62,402	$ 81,885
Gross unrealized gains	22,879	20,886
Fair value	85,281	102,771
Net average price	$ 17.48	$ 21.83
Residential mortgage-backed securities - agencies [Member]
Available for sale Investments (substantially restricted)
Amortized cost	45,828	65,211
Gross unrealized gains	3,786	4,501
Fair value	49,614	69,712
Net average price	$ 109.04	$ 107.63
Other asset-backed securities [Member]
Available for sale Investments (substantially restricted)
Amortized cost	8,615	8,951
Gross unrealized gains	18,082	15,281
Fair value	26,697	24,232
Net average price	$ 6.16	$ 5.49
United States government agencies [Member]
Available for sale Investments (substantially restricted)
Amortized cost	7,959	7,723
Gross unrealized gains	1,011	1,104
Fair value	$ 8,970	$ 8,827
Net average price	$ 99.67	$ 98.08

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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