| **Acquisitions and Divestitures - Narrative (Details) $ / shares in Units, $ in Thousands, shares in Millions** |          |          | 6 Months Ended |
|-----------------------------------------------------------------------------------------------------------------|----------|----------|----------------|
||
| **Business Acquisition [Line Items]**                                                                           |     |     |           |   |
| Common stock issued, value                                                                                      |     |     |                |  |
| Ameriana                                                                                                        |     |     |           |   |
| **Business Acquisition [Line Items]**                                                                           |     |     |           |   |
| Percentage of interest acquired                                                                                 | 100.00%  |     |           |   |
| Number of banking centers acquired | bank                                                                       | 13       |     |           |   |
| Stock issued as a part of acquisition (in shares) | shares                                                      | 2.8      |     |           |   |
| Common stock issued, value                                                                                      | $ 70,400 |     |           |   |
| Core deposit intangible                                                                                         | $ 5,342  |     |           |   |
| Acquired intangible asset, expected useful life                                                                 | 10 years |     |           |   |
| Purchase price                                                                                                  | $ 70,402 |     |           |   |
| Ameriana | Common Stock                                                                                         |     |     |           |   |
| **Business Acquisition [Line Items]**                                                                           |     |     |           |   |
| Number of shares of common stock                                                                                | 0.9037   |     |           |   |
| C Financial                                                                                                     |     |     |           |   |
| **Business Acquisition [Line Items]**                                                                           |     |     |           |   |
| Percentage of interest acquired                                                                                 |     | 100.00%  |           |   |
| Number of banking centers acquired | bank                                                                       |     | 6        |           |   |
| Core deposit intangible                                                                                         |     | $ 981    |           |   |
| Acquired intangible asset, expected useful life                                                                 |     | 10 years |           |   |
| Purchase price                                                                                                  |     | $ 14,500 |           |   |
| Cash received by shareholders for each share of common stock held (in dollars per share) | $ / shares           |     | $ 6.738  |           |   |
| Goodwill, expected tax deductible period                                                                        |     | 15 years |           |   |

| X                                                                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Business Acquisition, Goodwill, Expected Tax Deductible Period
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| X                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Business Combinations, Acquiree, Cash Received For Each Share Currently Owned
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| - Definition
Business Combinations, Acquiree, Shares of Stock Received For Each Share Currently Owned
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
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| 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
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of voting equity interests acquired at the acquisition date in the business combination.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of identifiable intangible assets recognized as of the acquisition date.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.
+ References
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| X                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of businesses acquired by the entity during the period.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of shares of stock issued during the period pursuant to acquisitions.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Value of stock issued pursuant to acquisitions during the period.
+ References
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