| **Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands** | Mar. 31, 2022 | Dec. 31, 2021 | Apr. 01, 2021 | Mar. 31, 2021 | Dec. 31, 2020 |
|-----------------------------------------------------------------------------------------------|---------------|---------------|---------------|---------------|---------------|
| **Business Acquisition [Line Items]**                                                         |          |          |          |          |          |
| Goodwill                                                                                      | $ 545,385     | $ 545,385     |          | $ 545,385     | $ 543,918     |
| Hoosier                                                                                       |          |          |          |          |          |
| **Business Acquisition [Line Items]**                                                         |          |          |          |          |          |
| Cash and cash equivalents                                                                     |          |          | $ 292         |          |          |
| Other assets                                                                                  |          |          | 35            |          |          |
| Other liabilities                                                                             |          |          | (816)         |          |          |
| Net tangible assets acquired                                                                  |          |          | (489)         |          |          |
| Customer relationship intangible                                                              |          |          | 2,247         |          |          |
| Goodwill                                                                                      |          |          | 1,467         |          |          |
| Purchase price                                                                                |          |          | $ 3,225       |          |          |

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Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tangible Assets, Net
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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.
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The amount of identifiable intangible assets recognized as of the acquisition date.
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Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.
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Amount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.
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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.
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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
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