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LOANS AND ALLOWANCE FOR LOAN AND LEASE LOSSES (Schedule of Loans Acquired) (Details) - USD ($) $ in Thousands |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Apr. 01, 2025 | Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
American National |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Initial ACL at acquisition |  |  | $ 0 |  | $ (3,896)
Sandy Spring |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Initial ACL at acquisition |  | $ 0 |  | $ (28,265) |
Sandy Spring | PCD |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Book value of acquired loans at acquisition | $ 1,724,771 |  |  |  |
Initial ACL at acquisition | (28,265) |  |  |  |
Non-credit discount at acquisition | (162,140) |  |  |  |
Purchase Price | 1,534,366 |  |  |  |
Sandy Spring | Non-PCD |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |
Fair Value | 7,077,565 |  |  |  |
Gross contractual amounts receivable | 7,676,836 |  |  |  |
Estimate of contractual cash flows not expected to be collected | $ 130,113 |  |  |  |

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