Disclosures Regarding Fair Values Of Financial Instruments (Securities In An Unrealized Loss Position) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Disclosures Regarding Fair Values Of Financial Instruments [Abstract]
One year or greater, Fair Value	$ 6,621	$ 4,933
Less than one year, Fair Value	451,749	369,226
Fair Value, Total	458,370	374,159
One year or greater, Unrealized Loss	31	26
Less than one year, Unrealized Loss	811	1,275
Unrealized Loss, Total	$ 842	$ 1,301

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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- Definition

This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for less than twelve months for those securities which are categorized neither as held-to-maturity nor trading securities.

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- Definition

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

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- Definition

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