| **Investment Securities - Narrative (Details)**                                            | 12 Months Ended |
|--------------------------------------------------------------------------------------------|-----------------|
||
| **Schedule of Available for sale Securities and Held to maturity Securities [Line Items]** |            |   |   |
| Fair value of investments                                                                  | $ 510,297,000   | $ 177,584,000 |   |
| Unrealized losses on mortgage-backed securities portfolio                                  | 9,674,000       | 578,000 |   |
| Unrealized losses in available for sale and held to maturity portfolios                    | 3,802,000       | 802,000 |   |
| Carrying value of securities pledged as collateral                                         | 572,896,000     | 637,358,000 | $ 449,408,000 |
| Securities sold under repurchase agreements                                                | 145,936,000     | 153,789,000 |   |
| Gross gains on securities sold                                                             | 3,389,000       | 2,770,000 | 3,581,000 |
| Gross losses from sale of available for sale securities                                    | 0               | 100,000 | $ 0 |
| Investments in Debt and Equity Securities, Reported at Less than Historical Cost           |            |   |   |
| **Schedule of Available for sale Securities and Held to maturity Securities [Line Items]** |            |   |   |
| Historical cost                                                                            | 523,773,000     | 178,964,000 |   |
| Fair value of investments                                                                  | $ 510,297,000   | $ 177,584,000 |   |
| Percent of the Corporation's available for sale and held to maturity portfolio             | 39.10%          | 13.90% |   |
| U.S. Government-Sponsored Mortgage-backed Securities                                       |            |   |   |
| **Schedule of Available for sale Securities and Held to maturity Securities [Line Items]** |            |   |   |
| Unrealized losses on mortgage-backed securities portfolio                                  | $ 3,071,000     | $ 518,000 |   |
| Available-for-sale, number of securities in unrealized loss positions | security           | 46              |   |   |
| Unrealized losses in available for sale and held to maturity portfolios                    | $ 1,527,000     | 787,000 |   |
| Held-to-maturity, number of securities in unrealized loss positions | security             | 29              |   |   |
| State and Municipal Securities                                                             |            |   |   |
| **Schedule of Available for sale Securities and Held to maturity Securities [Line Items]** |            |   |   |
| Unrealized losses on mortgage-backed securities portfolio                                  | $ 5,564,000     | 60,000 |   |
| Available-for-sale, number of securities in unrealized loss positions | security           | 108             |   |   |
| Unrealized losses in available for sale and held to maturity portfolios                    | $ 1,796,000     | 15,000 |   |
| Held-to-maturity, number of securities in unrealized loss positions | security             | 71              |   |   |
| U.S. Government-sponsored agency securities                                                |            |   |   |
| **Schedule of Available for sale Securities and Held to maturity Securities [Line Items]** |            |   |   |
| Unrealized losses on mortgage-backed securities portfolio                                  | $ 0             |  |   |
| Available-for-sale, number of securities in unrealized loss positions | security           | 0               |   |   |
| Unrealized losses in available for sale and held to maturity portfolios                    | $ 479,000       |   |   |
| Held-to-maturity, number of securities in unrealized loss positions | security             | 4               |   |   |
| Equity securities                                                                          |            |   |   |
| **Schedule of Available for sale Securities and Held to maturity Securities [Line Items]** |            |   |   |
| Unrealized losses on mortgage-backed securities portfolio                                  | $ 1,039,000     |  |   |
| Available-for-sale, number of securities in unrealized loss positions | security           | 1               |   |   |
| Unrealized losses in available for sale and held to maturity portfolios                    | $ 0             |   |   |
| Held-to-maturity, number of securities in unrealized loss positions | security             | 0               |   |   |

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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
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| - Definition
Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.
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| - Definition
This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.
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| - Definition
Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.
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| - Definition
Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity investments determined to be temporarily impaired.
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of asset associated with funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price.
+ References
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