| **Acquisitions and Divestitures (Tables)**                                                      | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
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| **Business Acquisition [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule of Pro Forma Information from Acquisition                                              | The following schedule includes pro forma results for the periods ended December 31, 2015 and 2014 as if the Ameriana and Community acquisitions had occurred as of the beginning of the comparable prior annual reporting period.  Pro forma financial information of the C Financial acquisition is not included in the table below as it is deemed immaterial. 2015 2014Total revenue (net interest income plus other income)$291,614 $284,890Net income$60,497 $64,174Net income available to common shareholders$60,497 $64,174Earnings per share:   Basic$1.49 $1.58Diluted$1.48 $1.57                                                                                             |
| Merger with Ameriana Bancorp                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| **Business Acquisition [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule of Preliminary Valuations of the Fair Value of Assets Acquired and Liabilities Assumed | The purchase price of the Ameriana acquisition was allocated as follows:  Fair ValueCash and cash equivalents $4,068Interest-bearing time deposits 8,790Investment securities 61,754Loans 316,929Premises and equipment 13,946Federal Home Loan Bank stock 2,693Other real estate owned 5,613Interest receivable 1,306Cash surrender value of life insurance 28,188Other assets 6,713Deposits (383,718)Interest payable (24)Federal Home Loan Bank Advances (24,884)Subordinated Debentures (5,487)Other liabilities (9,451)Net tangible assets acquired 26,436Core deposit intangible 5,342Goodwill 38,624Purchase price $70,402 |
| Merger with C Financial Corporation                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| **Business Acquisition [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule of Preliminary Valuations of the Fair Value of Assets Acquired and Liabilities Assumed | The purchase price of the C Financial acquisition was allocated as follows:  Fair ValueCash and cash equivalents $2,496Federal Funds sold 7,018Interest-bearing time deposits 922Loans 110,625Premises and equipment 7,290Federal Home Loan Bank stock 855Interest receivable 292Other assets 119Deposits (105,326)Interest payable (29)Federal Home Loan Bank Advances (18,958)Other liabilities (2,911)Net tangible assets acquired 2,393Core deposit intangible 981Goodwill 11,126Purchase price $14,500                                                                                                                                      |
| Merger with Community Bancshares, Inc.                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| **Business Acquisition [Line Items]**                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule of Preliminary Valuations of the Fair Value of Assets Acquired and Liabilities Assumed | The purchase price of the Community acquisition was allocated as follows: Fair ValueCash and cash equivalents$4,124Interest -bearing time deposits16,526Investment Securities, available for sale76,807Loans145,064Premises and equipment3,610Federal Home Loan Bank stock1,950Interest Receivable767Cash surrender value of life insurance3,266Other real estate owned6,662Taxes, deferred and receivable3,348Other assets167Deposits(228,424)Interest payable(98)Other liabilities(3,014)Net tangible assets acquired$30,755Core deposit intangible4,658Goodwill13,776Purchase price$49,189                                                                                                                                         |

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| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
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| - Definition
Tabular disclosure of pro forma results of operations for a material business acquisition or series of individually immaterial business acquisitions that are material in the aggregate.
+ References
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| - Definition
Tabular disclosure of the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed. May include but not limited to the following: (a) acquired receivables; (b) contingencies recognized at the acquisition date; and (c) the fair value of noncontrolling interests in the acquiree.
+ References
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