Summary of Financial Effects of Troubled Debt Restructurings (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014 Investment	Dec. 31, 2013 Investment
Financing Receivable, Modifications [Line Items]
Trouble debt restructuring, number of loans	8
Trouble debt restructuring, charge-off amount	352
Capitalized interest	22
Multi-Family
Financing Receivable, Modifications [Line Items]
Trouble debt restructuring, number of loans	2	1
Weighted Average Interest Rate, Pre-Modification	5.61%
Weighted Average Interest Rate, Post-Modification	5.61%
Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Trouble debt restructuring, number of loans	2	1
Weighted Average Interest Rate, Pre-Modification	6.71%
Weighted Average Interest Rate, Post-Modification	5.54%
Trouble debt restructuring, charge-off amount	334
One-to-four family
Financing Receivable, Modifications [Line Items]
Trouble debt restructuring, number of loans	1
Weighted Average Interest Rate, Pre-Modification	5.75%
Weighted Average Interest Rate, Post-Modification	4.27%
Trouble debt restructuring, charge-off amount	18
Capitalized interest	22
Acquisition, Development and Construction
Financing Receivable, Modifications [Line Items]
Trouble debt restructuring, number of loans	2
Weighted Average Interest Rate, Pre-Modification	7.00%
Weighted Average Interest Rate, Post-Modification	7.00%
Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Trouble debt restructuring, number of loans	1	2
Weighted Average Interest Rate, Pre-Modification	5.00%
Weighted Average Interest Rate, Post-Modification	5.00%

Weighted Average Interest Rate Post Modification

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Weighted Average Interest Rate Pre Modification

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 33

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524

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Reflects the amount of the write-down related to a troubled debt restructuring.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

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The gross interest income that would have been recorded in the period on troubled debt restructurings, if the loans had been current in accordance with their original terms and had been outstanding throughout the period or since origination, if held for part of the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 50

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