Disclosures Regarding Fair Values Of Financial Instruments (Securities In An Unrealized Loss Position) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Disclosures Regarding Fair Values Of Financial Instruments [Abstract]
One year or greater, Fair Value	$ 3,126	$ 1,694
Less than one year, Fair Value	296,755	334,224
Fair value, Total	299,881	335,918
One year or greater, Unrealized Loss	16	2
Less than one year, Unrealized Loss	682	1,315
Unrealized loss, Total	$ 698	$ 1,317

Disclosures Regarding Fair Values Of Financial Instruments [Abstract]

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This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized neither as held-to-maturity nor trading securities.

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This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

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