| **Loans and Allowance - Summary of Troubled Debt Restructurings by Modification (Details) - USD ($) $ in Thousands** | Dec. 31, 2016 | Dec. 31, 2015 |
|----------------------------------------------------------------------------------------------------------------------|---------------|---------------|
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | $ 6,263       | $ 5,378       |
| Term Modification                                                                                                    |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 1,195         | 2,815         |
| Rate Modification                                                                                                    |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 1,215         | 439           |
| Combination                                                                                                          |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 3,853         | 2,124         |
| Commercial and industrial loans                                                                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 397           | 1,814         |
| Commercial and industrial loans | Term Modification                                                                  |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          | 761           |
| Commercial and industrial loans | Combination                                                                        |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 397           | 1,053         |
| Agriculture production financing and other loans to farmers                                                          |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 672           |          |
| Agriculture production financing and other loans to farmers | Term Modification                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 660           |          |
| Agriculture production financing and other loans to farmers | Rate Modification                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 12            |          |
| Commercial and farmland                                                                                              |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 3,753         | 2,257         |
| Commercial and farmland | Term Modification                                                                          |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 297           | 1,231         |
| Commercial and farmland | Rate Modification                                                                          |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          |               |
| Commercial and farmland | Combination                                                                                |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 3,456         | 1,026         |
| Residential                                                                                                          |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 1,166         | 1,038         |
| Residential | Term Modification                                                                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 238           | 823           |
| Residential | Rate Modification                                                                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 928           | 170           |
| Residential | Combination                                                                                            |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          | 45            |
| Home equity                                                                                                          |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 266           | 242           |
| Home equity | Term Modification                                                                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          |               |
| Home equity | Rate Modification                                                                                      |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 266           | 242           |
| Home equity | Combination                                                                                            |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          |               |
| Individuals' loans for household and other personal expenditures                                                     |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | 9             | 27            |
| Individuals' loans for household and other personal expenditures | Term Modification                                 |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          |               |
| Individuals' loans for household and other personal expenditures | Rate Modification                                 |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   | $ 9           | 27            |
| Individuals' loans for household and other personal expenditures | Combination                                       |          |          |
| **Financing Receivable, Modifications [Line Items]**                                                                 |          |          |
| Total Modification                                                                                                   |          |               |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - 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
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Recorded Investment -URI http://asc.fasb.org/extlink&oid=65880944
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