Derivative Financial Instruments (Schedule of Fair Value of Derivative Financial Instruments) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Derivative assets designated as hedging instruments	$ 4,519	$ 4,766
Derivative assets not designated as hedging instruments	26,450	28,655
Total derivative assets	30,969	33,421
Derivative liabilities not designated as hedging instruments	26,692	29,060
Total derivative liabilities	26,692	29,060
Other Assets [Member]
Derivative assets designated as hedging instruments	4,519	4,766
Other Assets [Member] \| Interest Rate Contracts [Member]
Derivative assets not designated as hedging instruments	26,216	28,269
Other Assets [Member] \| Commodity Contracts [Member]
Derivative assets not designated as hedging instruments	0	132
Other Assets [Member] \| Mortgage Contracts [Member]
Derivative assets not designated as hedging instruments	234	254
Other Liabilities [Member] \| Interest Rate Contracts [Member]
Derivative liabilities not designated as hedging instruments	26,692	28,928
Other Liabilities [Member] \| Commodity Contracts [Member]
Derivative liabilities not designated as hedging instruments	$ 0	$ 132

Fair value of a derivative asset (or nonderivative instrument) that is designated and qualifies as a hedging instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 205G

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44C
-Subparagraph a
-Clause 1

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Fair value of a derivative asset that is not designated or qualifying as a hedging instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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- Definition

Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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Fair value of derivative liability, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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Fair value of a derivative liability that is not designated or qualifying as a hedging instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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