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Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments [Line Items]
Credit value adjustment	$ (2,207)	$ (2,963)
Interest rate derivatives	223,448	187,368
Risk participation agreements	71,390	128,098
Sold credit protection on risk participation agreements	$ 0	$ (22,147)

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- Details

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X

- Definition

Derivatives mark to market adjustment.

+ References

No definition available.

+ Details

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X

- Definition

Notional amount of risk participation agreement.

+ References

No definition available.

+ Details

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X

- Definition

Sold credit protection on risk participation agreements.

+ References

No definition available.

+ Details

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X

- Definition

Aggregate notional amount of interest rate derivatives, which relates to the currency amount specified in the interest rate derivative instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959

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