Fair Value Measurements - Carrying Values and Estimated Fair Values of Company's Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financial Assets
Securities	$ 83,292us-gaap_AvailableForSaleSecurities	$ 103,301us-gaap_AvailableForSaleSecurities
Restricted securities	1,366us-gaap_RestrictedInvestments	1,804us-gaap_RestrictedInvestments
Bank owned life insurance	11,357us-gaap_BankOwnedLifeInsurance	10,978us-gaap_BankOwnedLifeInsurance
Accrued interest receivable	1,261us-gaap_InterestReceivable	1,302us-gaap_InterestReceivable
Carrying Amount [Member]
Financial Assets
Cash and short-term investments	24,845	31,508
Securities	83,292	103,301
Restricted securities	1,366	1,804
Loans held for sale	328
Loans, net	371,692	346,449
Bank owned life insurance	11,357	10,978
Accrued interest receivable	1,261	1,302
Financial Liabilities
Deposits	444,338	450,711
Federal funds purchased	52
Other borrowings	26	6,052
Trust preferred capital notes	9,279	9,279
Accrued interest payable	135	177
Fair Value [Member]
Financial Assets
Cash and short-term investments	24,845	31,508
Securities	83,292	103,301
Restricted securities	1,366	1,804
Loans held for sale	328
Loans, net	378,930	353,874
Bank owned life insurance	11,357	10,978
Accrued interest receivable	1,261	1,302
Financial Liabilities
Deposits	444,210	451,377
Federal funds purchased	52
Other borrowings	26	6,095
Trust preferred capital notes	9,756	9,399
Accrued interest payable	135	177
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fair Value [Member]
Financial Assets
Cash and short-term investments	24,845	31,508
Securities	6	5
Significant Other Observable Inputs (Level 2) [Member] \| Fair Value [Member]
Financial Assets
Securities	83,286	103,296
Restricted securities	1,366	1,804
Loans held for sale	328
Bank owned life insurance	11,357	10,978
Accrued interest receivable	1,261	1,302
Financial Liabilities
Deposits	342,604	326,955
Federal funds purchased	52
Accrued interest payable	135	177
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value [Member]
Financial Assets
Loans, net	378,930	353,874
Financial Liabilities
Deposits	101,606	124,422
Other borrowings	26	6,095
Trust preferred capital notes	$ 9,756	$ 9,399

Other borrowings fair value disclosure.

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Trust preferred capital notes fair value disclosure.

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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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-SubTopic 10

-Section S99

-Paragraph 1

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- Definition

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

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- Definition

The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

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-Publisher SEC

-Name Regulation S-X (SX)

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-Section 03

-Paragraph 10

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

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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 portion of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

+ References

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- Definition

Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8)

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-Paragraph 8

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- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

+ References

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- Definition

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

Investments which are not defined as or included in marketable (debt, equity, or other) securities whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet.

+ References

No definition available.

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