| **Fair Values of Financial Instruments (Tables)**                                                                                                                                      | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| **Fair Value Disclosures [Abstract]**                                                                                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Fair Value Measurements of Assets and Liabilities Recognized in Consolidated Condensed Balance Sheets Measured at Fair Value                                                           | The following table presents the fair value measurements of assets and liabilities recognized in the accompanying balance sheets measured at fair value on a recurring basis and the level within the ASC 820-10 fair value hierarchy in which the fair value measurements fall at December 31, 2014 and 2013.    Fair Value Measurements Using:    Quoted Prices in ActiveMarkets for Identical Assets Significant Other Observable Inputs SignificantUnobservable InputsDecember 31, 2014 Fair Value (Level 1) (Level 2) (Level 3)Available for sale securities:        U.S. Government-sponsored agency securities $109   $109  State and municipal 228,593   221,982 $6,611U.S. Government-sponsored mortgage-backed securities 319,104   319,104  Corporate obligations 31     31Equity securities 1,706   1,702 4Interest rate swap asset 3,730   3,730  Interest rate cap 137   137  Interest rate swap liability 6,537   6,537      Fair Value Measurements Using:    Quoted Prices in ActiveMarkets for Identical Assets Significant Other Observable Inputs SignificantUnobservable InputsDecember 31, 2013 Fair Value (Level 1) (Level 2) (Level 3)Available for sale securities:        U.S. Treasury $15,973   $15,973  U.S. Government-sponsored agency securities 3,545   3,545  State and municipal 230,987   223,752 $7,235U.S. Government-sponsored mortgage-backed securities 281,252   281,252  Corporate obligations 2,738     2,738Equity securities 1,706   1,702 4Interest rate swap asset 3,619   3,619  Interest rate cap 390   390  Interest rate swap liability 3,953   3,953   |
| Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements Recognized in Consolidated Condensed Balance Sheets using Significant Unobservable Level 3 Inputs | The following is a reconciliation of the beginning and ending balances of recurring fair value measurements recognized in the accompanying balance sheets using significant unobservable Level 3 inputs for year ended December 31, 2014 and 2013. Available for Sale Securities For The Year Ended December 31, 2014 December 31, 2013Beginning Balance$9,977 $18,328Included in other comprehensive income3,656 1,330Purchases, issuances, and settlements  7,590Transfers in/(out) of Level 3  (16,434)Principal payments(6,987) (837)Ending balance$6,646 $9,977                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Transfer Between Levels 1, 2 and 3 and Reasons For Transfers                                                                                                                           | TRANSFERS BETWEEN LEVELS Quoted Prices in ActiveMarkets for Identical Assets Significant Other Observable Inputs SignificantUnobservable Inputs  December 31, 2013(Level 1) (Level 2) (Level 3) Reason for Transfer Transfers to/(from) Level:       Available for sale securities  $(350) $350 Selected state and municipal securities were transferred from Level 2 to Level 3 due to limited availability of similar securities in active markets.Available for sale securities transferred to held to maturity   $(16,784) Selected state and municipal securities were transferred from available for sale to held to maturity.  These securities are valued at amortized cost and are no longer classified within the fair value hierarchy.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Description of Valuation Methodologies Used for Instruments Measured at Fair Value on a Non-Recurring Basis and Recognized in Consolidated Condensed Balance Sheets                    | Following is a description of valuation methodologies used for instruments measured at fair value on a non-recurring basis and recognized in the accompanying balance sheets, as well as the general classification of such instruments pursuant to the valuation hierarchy for year ended December 31, 2014 and 2013.  Fair Value Measurements Using  Quoted Prices in ActiveMarkets for Identical AssetsSignificant Other Observable InputsSignificantUnobservable InputsDecember 31, 2014Fair Value(Level 1)(Level 2)(Level 3)Impaired Loans (collateral dependent)$17,134$17,134Other real estate owned $5,155$5,155  Fair Value Measurements Using  Quoted Prices in ActiveMarkets for Identical AssetsSignificant Other Observable InputsSignificantUnobservable InputsDecember 31, 2013Fair Value(Level 1)(Level 2)(Level 3)Impaired Loans (collateral dependent)$12,117  $12,117Other real estate owned$6,877  $6,877                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Unobservable Inputs Used in Recurring and Nonrecurring Level 3 Fair Value Measurements Other Than Goodwill                                                                             | The following table presents quantitative information about unobservable inputs used in recurring and nonrecurring Level 3 fair value measurements, other than goodwill, at December 31, 2014 and 2013.December 31, 2014Fair Value Valuation Technique Unobservable Inputs Range            (Weighted-Average)State and municipal securities$6,611 Discounted cash flow Maturity Call DateUS Muni BQ curveDiscount rate 1 month to 15 yearsA- to BBB-.90% - 5%        Corporate obligations and Equity securities$35 Discounted cash flow Risk free rateplus Premium for illiquidity 3 month LIBORplus 200 bps        Impaired loans (collateral dependent)$17,134 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 50%                 (3%)        Other real estate owned$5,155 Appraisals Discount to reflect current market conditions 0% - 20%                 (7%)December 31, 2013Fair Value Valuation Technique Unobservable Inputs Range            (Weighted-Average)State and municipal securities$7,235 Discounted cash flow Maturity Call DateUS Muni BQ curveDiscount rate 1 month to 15 yearsA- to BBB-1% - 5%        Corporate obligations and Equity securities$2,742 Discounted cash flow Risk free rateplus Premium for illiquidity 3 month LIBORplus 200 bps        Impaired loans (collateral dependent)$12,117 Collateral based measurements Discount to reflect current market conditions and ultimate collectability 0% - 50%                 (3%)        Other real estate owned$6,877 Appraisals Discount to reflect current market conditions 0% - 20%                 (2%)                                                                                                                                                                                                                                                                                                                                      |
| Estimated Fair Values of Financial Instruments                                                                                                                                         | The following table presents estimated fair values of the Corporation's financial instruments and the level within the fair value hierarchy in which the fair value measurements fall at December 31, 2014 and 2013. 2014 CarryingAmountQuoted Prices in Active Markets for Identical Assets (Level 1)Significant Other Observable Inputs(Level 2)Significant Unobservable Inputs(Level 3)Assets at December 31:   Cash and cash equivalents$118,616$118,616Interest-bearing time deposits47,52047,520Investment securities available for sale549,543$542,897$6,646Investment securities held to maturity631,088614,45733,266Loans held for sale7,2357,235Loans3,860,9013,810,912FRB and FHLB stock41,35341,353Interest rate swap asset3,8673,867Interest receivable19,98419,984Liabilities at December 31:Deposits$4,640,694$3,523,199$1,099,610Borrowings:Federal funds purchased15,38115,381Securities sold under repurchase agreements124,539124,539FHLB Advances145,264146,669Subordinated debentures and term loans126,81092,802Interest rate swap liability6,5376,537Interest payable3,2013,201 2013 CarryingAmountQuoted Prices in Active Markets for Identical Assets (Level 1)Significant Other Observable Inputs(Level 2)Significant Unobservable Inputs(Level 3)Assets at December 31:   Cash and cash equivalents$109,434$109,434Interest-bearing time deposits55,06955,069Investment securities available for sale536,201$526,224$9,977Investment securities held to maturity559,378525,99834,849Loans held for sale5,3315,331Loans3,564,5393,506,615FRB and FHLB stock38,99038,990Interest rate swap asset4,0094,009Interest receivable18,67218,672Liabilities at December 31:Deposits$4,231,468$3,082,117$934,937Borrowings:Federal funds purchased125,645125,645Securities sold under repurchase agreements148,672148,852FHLB Advances122,140122,962Subordinated debentures and term loans126,80782,607Interest rate swap liability3,9533,953Interest payable1,7711,771                                                                                                                                                                                                                                                                                                                                                                              |

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| - Definition
Fair Value, Assets And Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation
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Transfers In And Out Of Each Of Valuation Levels Of Fair Values Table
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| - Definition
Tabular disclosure of the inputs and valuation techniques used to measure fair value, and a discussion of changes in valuation techniques and related inputs, if any, applied during the period to each separate class of assets, liabilities, and financial instruments classified in shareholders' equity that are measured on a recurring and/or nonrecurring basis.
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| - Definition
Tabular disclosure of assets and liabilities by class, including financial instruments measured at fair value that are classified in shareholders' equity, if any, that are measured at fair value on a nonrecurring basis in periods after initial recognition (for example, impaired assets). Disclosures may include, but are not limited to: (a) the fair value measurements recorded and the reasons for the measurements and (b) the level within the fair value hierarchy in which the fair value measurements are categorized in their entirety (levels 1, 2, 3).
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| - Definition
Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.
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| - Definition
Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).
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