Federal Home Loan Bank Advances - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Securities Pledged As Collateral [Line Items]
Federal Home Loan Bank advances amount	$ 47,494	$ 42,497
Maximum borrowing capacity of the Bank	76,187
Unused collateral borrowing capacity	27,169
Cash management line of credit	40,000
Amount outstanding	0	0
Multi-family mortgage loans [Member]
Securities Pledged As Collateral [Line Items]
Investment securities	87,478
Residential real estate mortgage loans [Member]
Securities Pledged As Collateral [Line Items]
Investment securities	$ 34,550

Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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