Fair Value Measurements - Carrying Values and Estimated Fair Values of Company's Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financial Assets
Securities	$ 90,855us-gaap_AvailableForSaleSecurities	$ 83,292us-gaap_AvailableForSaleSecurities
Restricted securities	1,999us-gaap_RestrictedInvestments	1,366us-gaap_RestrictedInvestments
Bank owned life insurance	11,431us-gaap_BankOwnedLifeInsurance	11,357us-gaap_BankOwnedLifeInsurance
Accrued interest receivable	1,256us-gaap_InterestReceivable	1,261us-gaap_InterestReceivable
Carrying Amount [Member]
Financial Assets
Cash and short-term investments	9,174	24,845
Securities	90,855	83,292
Restricted securities	1,999	1,366
Loans held for sale		328
Loans, net	391,746	371,692
Bank owned life insurance	11,431	11,357
Accrued interest receivable	1,256	1,261
Financial Liabilities
Deposits	438,786	444,338
Federal funds purchased	1,955	52
Other borrowings	15,020	26
Trust preferred capital notes	9,279	9,279
Accrued interest payable	120	135
Fair Value [Member]
Financial Assets
Cash and short-term investments	9,174	24,845
Securities	90,855	83,292
Restricted securities	1,999	1,366
Loans held for sale		328
Loans, net	399,848	378,930
Bank owned life insurance	11,431	11,357
Accrued interest receivable	1,256	1,261
Financial Liabilities
Deposits	438,807	444,210
Federal funds purchased	1,955	52
Other borrowings	15,020	26
Trust preferred capital notes	9,547	9,756
Accrued interest payable	120	135
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Fair Value [Member]
Financial Assets
Cash and short-term investments	9,174	24,845
Securities	6	6
Significant Other Observable Inputs (Level 2) [Member] \| Fair Value [Member]
Financial Assets
Securities	90,849	83,286
Restricted securities	1,999	1,366
Loans held for sale		328
Bank owned life insurance	11,431	11,357
Accrued interest receivable	1,256	1,261
Financial Liabilities
Deposits	341,812	342,604
Federal funds purchased	1,955	52
Accrued interest payable	120	135
Significant Unobservable Inputs (Level 3) [Member] \| Fair Value [Member]
Financial Assets
Loans, net	399,848	378,930
Financial Liabilities
Deposits	96,995	101,606
Other borrowings	15,020	26
Trust preferred capital notes	$ 9,547	$ 9,756

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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-Topic 210

-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

-Section S99

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-Subparagraph (SX 210.9-03.10)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-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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- 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 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)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Number 210

-Section 02

-Paragraph 8

-Article 5

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- Definition

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

+ References

No definition available.

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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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