Loans - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2012	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Percentage of loan portfolio to earning assets		60.10%	62.40%
Loan to value ratio	80.00%	80.00%
Gross interest income if non-accrual loans had been current	$ 75,900	$ 145,300
Troubled debt restructurings, balance	210,000	210,000
Impaired receivables for which allowance for credit losses had previously been measured under general allowance for credit losses methodology	210,000	210,000
Impaired receivables for which allowance for credit losses had previously been measured under general allowance for credit losses methodology, allowance for credit losses	$ 53,000	$ 53,000

Loans To Earning Assets Percentage

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- Definition

Loan To Value Ratio

+ References

No definition available.

+ Details

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- Definition

Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 40

-Section 65

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7484272&loc=SL7484277-172609

+ Details

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- Definition

The amount of the outstanding recorded investment related to 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 40

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6951948&loc=d3e18845-111554

+ Details

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- Definition

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 Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph j(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 15

-Paragraph 40

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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- Definition

Amount of receivables for which the allowance for credit losses had previously been measured under a general allowance for credit losses methodology, and are now identified as troubled debt restructurings.

+ References

+ Details

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