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ACQUISITIONS - Supplemental Pro Forma Financial Information (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Business Acquisition [Line Items] |  |  |  |
Total revenue, net of interest expense, pro forma | $ 170,242 | $ 157,683 | $ 337,102 | $ 317,040
Net income, pro forma | 43,426 | $ 49,338 | 92,021 | $ 100,014
Steuben Trust Corporation [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Acquisitions-related expenses | $ 4,000 |  | $ 4,300 |

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