Fair Value Measurements - Schedule of Balances of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Securities available for sale:
Securities available-for-sale	$ 42,604us-gaap_AvailableForSaleSecurities	$ 38,522us-gaap_AvailableForSaleSecurities
Mortgage servicing rights	596us-gaap_ServicingAssetAtFairValueAmount	579us-gaap_ServicingAssetAtFairValueAmount
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	2,897	2,820
US Government Agencies
Securities available for sale:
Securities available-for-sale	16,965	9,308
State and Municipal Obligations
Securities available for sale:
Securities available-for-sale	23,401	26,557
Auction Rate Security
Securities available for sale:
Securities available-for-sale		912
Certificates of Deposit
Securities available for sale:
Securities available-for-sale	2,238	1,745
Cash and Cash Equivalents
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	4	3
Fixed Income Funds
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	1,139	1,070
Equity Funds
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	1,754	1,747
Fair Value, Inputs, Level 1
Securities available for sale:
Securities available-for-sale	845
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	2,897	2,820
Fair Value, Inputs, Level 1 \| US Government Agencies
Securities available for sale:
Securities available-for-sale	845
Fair Value, Inputs, Level 1 \| Cash and Cash Equivalents
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	4	3
Fair Value, Inputs, Level 1 \| Fixed Income Funds
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	1,139	1,070
Fair Value, Inputs, Level 1 \| Equity Funds
Defined benefit plan assets:
Defined Benefit Plan Fair Value Of Plan Assets	1,754	1,747
Fair Value, Inputs, Level 2
Securities available for sale:
Securities available-for-sale	41,759	37,610
Fair Value, Inputs, Level 2 \| US Government Agencies
Securities available for sale:
Securities available-for-sale	16,120	9,308
Fair Value, Inputs, Level 2 \| State and Municipal Obligations
Securities available for sale:
Securities available-for-sale	23,401	26,557
Fair Value, Inputs, Level 2 \| Certificates of Deposit
Securities available for sale:
Securities available-for-sale	2,238	1,745
Fair Value, Inputs, Level 3
Securities available for sale:
Securities available-for-sale		912
Mortgage servicing rights	596	579
Fair Value, Inputs, Level 3 \| Auction Rate Security
Securities available for sale:
Securities available-for-sale		$ 912

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

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- Definition

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

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

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