Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Held to Maturity [Abstract]
Carrying value	$ 79,787	$ 0
Cost or amortized cost	79,787	0
Fair value	79,794	0
Trading [Abstract]
Carrying Value	0	212
Cost or amortized cost	0	224
Fair Value	0	212
Gross unrealized gains (losses) on investment securities held to maturity [Abstract]
Gross unrealized gains (losses)	7	0
Unrealized losses on investment securities held for trading [Abstract]
Cost basis	0	224
Current value	0	212
Unrealized gains (losses)	0	(12)
Realized gain on the sales of investment securities held for trading [Abstract]
Net sale proceeds	931	556
Cost basis	(893)	(537)
Realized gains (losses)	38	19
US Treasury Bills [Member]
Held to Maturity [Abstract]
Carrying value	79,787	0
Cost or amortized cost	79,787	0
Fair value	79,794	0
Equity Securities [Member]
Trading [Abstract]
Carrying Value	0	212
Cost or amortized cost	0	224
Fair Value	0	212
Unrealized losses on investment securities held for trading [Abstract]
Cost basis	0	224
Current value	$ 0	$ 212

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The cash inflow from sales of trading securities during the period. Trading securities are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time).

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The carrying value of financial instruments that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time).

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No definition available.

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Trading securities sold during the period at cost basis.

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Amount of investments in debt securities categorized as held-to-maturity valued at amortized cost, excludes other than temporary impairment (OTTI).

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No definition available.

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Carrying amount of debt securities accounted for as held-to-maturity, net of adjustments including, but not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized, and fair value hedge accounting adjustments.

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-Name Statement of Financial Accounting Standard (FAS)

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This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

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As of the balance sheet date, the excess of fair value over carrying value (amortized cost) of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding gain.

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The total of financial instruments that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for debt and equity securities formerly categorized as available-for-sale or held-to-maturity which the entity held as of the date it opted to account for such securities at fair value. An enterprise may also categorize such a security as trading without the intent to sell it in the near term assuming the decision to categorize the security as trading occurred at acquisition.

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This item represents a parenthetical disclosure for the cost of securities classified as trading.

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This item represents the gain (loss) realized during the period from the sale of trading securities.

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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period. Trading securities are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) and the change in net unrealized holding gain (loss) is included in earnings for the period.

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