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Fair Values of Financial Instruments - Carrying Amount, Estimated Fair Value and Level Within Fair Value Hierarchy of Financial Instruments (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Financial assets:
Securities available for sale	$ 123,793,000	$ 138,314,000
Carrying Values [Member]
Financial assets:
Securities available for sale	123,793,000	138,314,000
FHLB stock	11,961,000	11,961,000
Carrying Values [Member] | Level 1 [Member]
Financial assets:
Cash	1,995,000	1,576,000
Carrying Values [Member] | Level 2 [Member]
Financial assets:
Cash equivalents	123,923,000	134,427,000
Bank owned life insurance	51,073,000	50,048,000
Accrued interest receivable	3,777,000	3,874,000
Financial liabilities:
Deposits	1,121,509,000	1,135,204,000
Repurchase agreements	65,680,000	64,765,000
FHLB advances	45,000,000	35,000,000
Subordinated debentures	32,990,000	32,990,000
Accrued interest payable	1,643,000	2,314,000
Carrying Values [Member] | Level 3 [Member]
Financial assets:
Loans, net	1,050,292,000	1,012,512,000
Carrying Values [Member] | Interest rate swap agreement [Member]
Financial liabilities:
Interest rate swap	394,000	1,113,000
Fair Values [Member]
Financial assets:
Securities available for sale	123,793,000	138,314,000
FHLB stock	11,961,000	11,961,000
Fair Values [Member] | Level 1 [Member]
Financial assets:
Cash	1,995,000	1,576,000
Fair Values [Member] | Level 2 [Member]
Financial assets:
Cash equivalents	123,923,000	134,427,000
Bank owned life insurance	51,073,000	50,048,000
Accrued interest receivable	3,777,000	3,874,000
Financial liabilities:
Deposits	1,123,304,000	1,135,614,000
Repurchase agreements	65,680,000	64,765,000
FHLB advances	45,139,000	35,000,000
Subordinated debentures	32,974,000	32,943,000
Accrued interest payable	1,643,000	2,314,000
Fair Values [Member] | Level 3 [Member]
Financial assets:
Loans, net	1,047,313,000	1,004,541,000
Fair Values [Member] | Interest rate swap agreement [Member]
Financial liabilities:
Interest rate swap	$ 394,000	$ 1,113,000

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- Definition

Fair value portion of accrued expenses.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5



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-Section S99

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

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- Definition

Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Surrender Value

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

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- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

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-Topic 825

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-Name Accounting Standards Codification

-Topic 210

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-Paragraph 3

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-Topic 210

-SubTopic 20

-Section 55

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=28370219&loc=SL20226008-175313

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- Definition

Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a),(b)

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- Definition

Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13(3)(a))

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- Definition

Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 20

-Section 25

-Paragraph 1

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Glossary Loan

-URI http://asc.fasb.org/extlink&oid=6517073

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- Definition

Fair value portion of securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

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