Unearned ESOP Shares - Analysis of ESOP Shares Held in Suspense and Its Fair Value (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Employee Stock Ownership Plan (ESOP), Shares in ESOP [Rollforward]
Shares in suspense, beginning of the year	104,661
Shares allocated	(104,661)
Shares acquired	0
Shares in suspense, end of the year	0
Fair market value of shares in suspense	$ 0

Employee Stock Ownership Plan Esop Fair Market Value of Suspense Shares

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- Definition

Employee Stock Ownership Plan (ESOP), Number Of Acquired Shares

+ References

No definition available.

+ Details

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- Definition

Shares contributed to the ESOP that have not yet been released, committed to be released, or allocated to participant accounts. Suspense shares generally collateralize ESOP debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 40

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

+ Details

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- Definition

This item represents the number of shares provided to the Employee Stock Ownership Plan (ESOP) during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 40

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

+ Details

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