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LOANS AND ALLOWANCE FOR CREDIT LOSSES - Narrative (Details) | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2025 USD ($) loan | Jun. 30, 2024 USD ($) loan | Sep. 30, 2023 | Jun. 30, 2025 USD ($) loan | Jun. 30, 2024 USD ($) loan | Dec. 31, 2024 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Accrued interest | $ 8,100,000 |  |  | $ 8,100,000 |  | $ 8,000,000.0
Loans, net of deferred loan fees | 2,132,414,000 |  |  | 2,132,414,000 |  | 2,071,419,000
Amortized cost basis | 0 | $ 440,000 |  | 0 | $ 440,000 |
Charge-offs | 1,120,000 | $ 449,000 |  | 1,519,000 | $ 816,000 | 1,873,000
Individually analyzed | 4,981,000 |  |  | $ 4,981,000 |  | 6,471,000
Number of days past due after which a retail loan is rated |  |  |  | 90 days |  |
Collateral Pledged |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Individually analyzed | 4,172,000 |  |  | $ 4,172,000 |  | 5,089,000
Commercial and industrial |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Loans, net of deferred loan fees | $ 294,474,000 |  |  | 294,474,000 |  | 299,521,000
Weighted-average term extension (in months) |  |  | 6 months |  |  |
Charge-offs |  |  |  | $ 777,000 |  | 302,000
Commercial and industrial | Defaulted Loan |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Modified contracts | loan | 0 | 0 |  | 0 | 1 |
Charge-offs | $ 700,000 |  |  | $ 700,000 |  |
Commercial Mortgages |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Loans, net of deferred loan fees | 1,297,525,000 |  |  | 1,297,525,000 |  | 1,217,004,000
Charge-offs | 0 | $ 0 |  | 0 | $ 0 |
Individually analyzed | 3,767,000 |  |  | 3,767,000 |  | 4,959,000
Commercial and Industrial |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Loans, net of deferred loan fees | 294,474,000 |  |  | 294,474,000 |  | 299,521,000
Charge-offs | 772,000 | $ 0 |  | 777,000 | $ 0 |
Individually analyzed | 861,000 |  |  | 861,000 |  | 1,512,000
Commercial Mortgages, Other Loan Category |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Loans, net of deferred loan fees | 1,200,000,000 |  |  | 1,200,000,000 |  | 1,120,000,000
Commercial and industrial |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |  |  |
Loans, net of deferred loan fees | 294,474,000 |  |  | $ 294,474,000 |  | $ 299,521,000
Laon transferred | $ 2,100,000 |  |  |  |  |

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