Disclosures About Fair Value of Assets and Liabilities - Estimated Fair Values of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Carrying (Reported) Amount
Assets:
Cash and due from banks	$ 69,404	$ 101,460
Interest-bearing time deposits	59,898	38,443
Investment securities available for sale	584,593	513,343
Investment securities held to maturity	324,399	361,020
Mortgage loans held for sale	14,531	22,300
Loans	2,851,878	2,832,843
Federal Reserve Bank and Federal Home Loan Bank stock	32,790	32,785
Interest rate swap and cap asset	3,626	6,300
Interest receivable	15,186	16,367
Liabilities:
Deposits	3,332,793	3,346,383
Borrowings:
Federal funds purchased	57,085	18,862
Securities sold under repurchase agreements	161,779	141,828
Federal Home Loan Bank advances	92,743	94,238
Subordinated debentures, revolving credit lines and term loans	111,778	112,161
Interest rate swap liability	4,661	9,766
Interest payable	1,150	1,841
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and due from banks	69,404	101,460
Interest-bearing time deposits	59,898	38,443
Liabilities:
Deposits	2,565,193	2,478,706
Significant Other Observable Inputs (Level 2)
Assets:
Investment securities available for sale	566,678	495,015
Investment securities held to maturity	320,861	366,590
Mortgage loans held for sale	14,531	22,300
Federal Reserve Bank and Federal Home Loan Bank stock	32,790	32,785
Interest rate swap and cap asset	3,626	6,300
Interest receivable	15,186	16,367
Liabilities:
Deposits	760,068	865,793
Borrowings:
Federal funds purchased	57,085	18,862
Securities sold under repurchase agreements	162,120	142,318
Federal Home Loan Bank advances	95,080	97,357
Subordinated debentures, revolving credit lines and term loans	63,563	62,133
Interest rate swap liability	4,661	9,766
Interest payable	1,150	1,841
Significant Unobservable Inputs (Level 3)
Assets:
Investment securities available for sale	17,915	18,328
Investment securities held to maturity	10,904	11,584
Loans	$ 2,826,038	$ 2,852,614

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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.

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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 includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Company may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months.

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- Definition

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