Borrowings - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2015 Unit	Dec. 31, 2014
Debt Instrument [Line Items]
Federal funds purchased	$ 0us-gaap_FederalFundsPurchased	$ 0us-gaap_FederalFundsPurchased
Weighted average rate of federal funds purchased		0.34%
Weighted average rate of retail repurchase agreements	0.12%	0.13%
Number of FHLB letters of credit	2
Letters of credit provided for collateralize public unit deposits	6,180,000
Qualifying loans	991,000	981,000
Junior subordinated debentures issued	15,460,000
Libor rate	2.95%
Debentures mature date	Oct. 08, 2033
Unrelated Financial Institution
Debt Instrument [Line Items]
Unsecured, committed line of credit, borrowing capacity	15,000,000
Unsecured, committed line of credit, interest rate	One-month LIBOR plus 2.00%
Unsecured, committed line of credit, base rate	2.00%
Unsecured, committed line of credit, maturity date	Apr. 30, 2015
Unsecured, committed line of credit, outstanding amount	0	2,000,000
Wholesale Repurchase Agreements
Debt Instrument [Line Items]
Weighted average contractual rate	3.71%	3.71%
FHLB Borrowings
Debt Instrument [Line Items]
Weighted average contractual rate	4.07%	4.07%
Unused borrowing capacity	$ 420,810,000

Number Of Federal Home Loan Bank Advances

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- Definition

Weighted average contractual rate.

+ References

No definition available.

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- Definition

Weighted Average Rate of Federal Funds Purchased

+ References

No definition available.

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- Definition

Weighted Average Rate of Retail Repurchase Agreements

+ References

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Topic 210

-SubTopic 10

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-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

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- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

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- Definition

Amount of securities, mortgage loans, or other financial instruments pledged as collateral for deposits.

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-Topic 942

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- Definition

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

+ References

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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-SubTopic 210

-Section S99

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-Subparagraph (SX 210.9-03.16)

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- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

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- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

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- Definition

The cash inflow from a borrowing where a lender is placed in a lien position behind debt having a higher priority of repayment (senior) in liquidation of the entity's assets or underlying collateral.

+ References

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-Glossary Financing Activities

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