This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References+ Details

- Definition

Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References+ Details

Disclosures Regarding Fair Value - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Investment securities available for sale
Available for sale securities fair value	$ 265,798	$ 264,502
Derivative financial instruments	350	370
Total assets measured at fair value on a recurring basis	266,148	264,872
Liabilities
Derivative financial instruments	61	5
State and municipal [Member]
Investment securities available for sale
Available for sale securities fair value	11,116	11,530
Collateralized mortgage obligations (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value	129,361	123,508
Other mortgage-backed (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value	61,767	63,817
SBA Loan-Backed (Federal Agency) [Member]
Investment securities available for sale
Available for sale securities fair value	63,554	65,647
Level 1 [Member]
Investment securities available for sale
Derivative financial instruments
Total assets measured at fair value on a recurring basis	43,180	58,740
Liabilities
Derivative financial instruments
Level 1 [Member] \| State and municipal [Member]
Investment securities available for sale
Available for sale securities fair value
Level 1 [Member] \| Collateralized mortgage obligations (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value		14,057
Level 1 [Member] \| Other mortgage-backed (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value
Level 1 [Member] \| SBA Loan-Backed (Federal Agency) [Member]
Investment securities available for sale
Available for sale securities fair value	43,180	44,683
Level 2 [Member]
Investment securities available for sale
Derivative financial instruments	350	370
Total assets measured at fair value on a recurring basis	222,968	206,132
Liabilities
Derivative financial instruments	61	5
Level 2 [Member] \| State and municipal [Member]
Investment securities available for sale
Available for sale securities fair value	11,116	11,530
Level 2 [Member] \| Collateralized mortgage obligations (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value	129,361	109,451
Level 2 [Member] \| Other mortgage-backed (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value	61,767	63,817
Level 2 [Member] \| SBA Loan-Backed (Federal Agency) [Member]
Investment securities available for sale
Available for sale securities fair value	20,374	20,964
Level 3 [Member]
Investment securities available for sale
Derivative financial instruments
Total assets measured at fair value on a recurring basis
Liabilities
Derivative financial instruments
Level 3 [Member] \| State and municipal [Member]
Investment securities available for sale
Available for sale securities fair value
Level 3 [Member] \| Collateralized mortgage obligations (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value
Level 3 [Member] \| Other mortgage-backed (federal agencies) [Member]
Investment securities available for sale
Available for sale securities fair value
Level 3 [Member] \| SBA Loan-Backed (Federal Agency) [Member]
Investment securities available for sale
Available for sale securities fair value