Federal Home Loan Bank Advances - Additional Information (Detail) (USD $)	Dec. 31, 2012
Schedule of Federal Home Loan Bank Advances and Other Borrowings [Line Items]
Mortgage loans pledged as collateral for advances, value	$ 444,100,000
Interest rates on advances, minimum	0.49%
Interest rates on advances, maximum	7.33%

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

States the lowest interest rate applicable to any of the advances from the Federal Home Loan Bank as of the Balance Sheet date.

+ References+ Details

- Definition

States the highest interest rate applicable to any of the advances from the Federal Home Loan Bank as of the Balance Sheet date.

+ References+ Details