Regulatory Matters - Summary of Bank's Actual Capital Amounts and Ratios (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Banking and Thrift [Abstract]
Tangible capital, Actual Amount	$ 223,573us-gaap_TangibleCapital	$ 217,776us-gaap_TangibleCapital
Tier 1 leverage, Actual Amount	223,573us-gaap_TierOneLeverageCapital	217,776us-gaap_TierOneLeverageCapital
Tier 1 risk-based capital, Actual Amount	223,573us-gaap_TierOneRiskBasedCapital	217,776us-gaap_TierOneRiskBasedCapital
Total risk-based capital, Actual Amount	239,940us-gaap_Capital	236,304us-gaap_Capital
Tangible capital, Actual Ratio	9.46%us-gaap_TangibleCapitalToTangibleAssets	9.66%us-gaap_TangibleCapitalToTangibleAssets
Tier 1 leverage, Actual Ratio	9.46%	9.66%
Tier 1 risk-based capital, Actual Ratio	14.05%	14.72%
Total risk-based capital, Actual Ratio	15.08%us-gaap_CapitalToRiskWeightedAssets	15.97%us-gaap_CapitalToRiskWeightedAssets
Tangible capital, For capital adequacy purposes Amount	35,465	33,830
Tier 1 leverage, For capital adequacy purposes Amount	94,573	90,215
Tier 1 risk-based capital, For capital adequacy purposes Amount	63,663	59,190
Total risk-based capital, For capital adequacy purposes Amount	127,325	118,380
Tangible capital, For capital adequacy purposes Ratio	1.50%	1.50%
Tier 1 leverage, For capital adequacy purposes Ratio	4.00%	4.00%
Tier 1 risk-based capital, For capital adequacy purposes Ratio	4.00%	4.00%
Total risk-based capital, For capital adequacy purposes Ratio	8.00%	8.00%
Tangible capital, To be well capitalized under prompt corrective action Amount	0	0
Tier 1 leverage, To be well capitalized under prompt corrective action Amount	118,217	112,768
Tier 1 risk-based capital, To be well capitalized under prompt corrective action Amount	95,494	88,785
Total risk-based capital, To be well capitalized under prompt corrective action Amount	$ 159,157	$ 147,975
Tangible capital, To be well capitalized under prompt corrective action Ratio	0.00%	0.00%
Tier 1 leverage, To be well capitalized under prompt corrective action Ratio	5.00%	5.00%
Tier 1 risk-based capital, To be well capitalized under prompt corrective action Ratio	6.00%	6.00%
Total risk-based capital, To be well capitalized under prompt corrective action Ratio	10.00%	10.00%

Tangible Capital Required To Be Well Capitalized Amount

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Tangible Capital Required To Be Well Capitalized To Tangible Assets

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The amount of total capital as defined in the regulations.

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The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

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The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

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Total Capital divided by risk weighted assets as defined in the regulations.

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Tangible capital as defined in the regulations (generally includes outstanding stock plus retained earnings) for banking institutions subject to Office of Thrift Supervision (OTS) capital requirements.

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The minimum amount of tangible capital required under the regulatory framework for prompt corrective action.

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The minimum amount of Tangible Capital divided by tangible assets (Tangible Capital Ratio) as defined in the regulations.

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Tangible Capital divided by Tangible assets as defined in the regulations.

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Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

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The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

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Tier 1 Leverage Capital divided by average assets as defined in the regulations.

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Tier 1 Risk Based Capital as defined in the regulations.

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The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

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The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

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The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

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Tier 1 capital divided by risk weighted assets as defined by regulations.

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