Parent Company Only Financial Statements - Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Other assets	$ 6,010us-gaap_OtherAssets	$ 7,876us-gaap_OtherAssets
Total assets	518,165us-gaap_Assets	522,890us-gaap_Assets
Liabilities and Shareholders' Equity
Other liabilities	4,906us-gaap_OtherLiabilities	3,288us-gaap_OtherLiabilities
Total liabilities	458,601us-gaap_Liabilities	469,330us-gaap_Liabilities
Preferred stock	14,595us-gaap_PreferredStockValue	14,564us-gaap_PreferredStockValue
Common stock	6,131us-gaap_CommonStockValue	6,127us-gaap_CommonStockValue
Surplus	6,835us-gaap_AdditionalPaidInCapital	6,813us-gaap_AdditionalPaidInCapital
Retained earnings	33,557	27,360
Accumulated other comprehensive loss, net	(1,554)	(1,304)	(859)	991
Total shareholders' equity	59,564us-gaap_StockholdersEquity	53,560us-gaap_StockholdersEquity	44,889us-gaap_StockholdersEquity	37,096us-gaap_StockholdersEquity
Total liabilities and shareholders' equity	518,165	522,890
Parent Company [Member]
Assets
Cash	2,421	5,395
Investment in subsidiaries, at cost, plus undistributed net income	65,744	56,982
Other assets	685	470
Total assets	68,850	62,847
Liabilities and Shareholders' Equity
Trust preferred capital notes	9,279	9,279
Other liabilities	7	8
Total liabilities	9,286	9,287
Preferred stock	14,595	14,564
Common stock	6,131	6,127
Surplus	6,835	6,813
Retained earnings	33,557	27,360
Accumulated other comprehensive loss, net	(1,554)	(1,304)
Total shareholders' equity	59,564	53,560
Total liabilities and shareholders' equity	$ 68,850	$ 62,847

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

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Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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