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v3.25.1

BORROWINGS (Details) $ in Millions |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Feb. 25, 2026 | Mar. 31, 2025 USD ($) | Dec. 31, 2024 USD ($) item
Secured short term borrowings through Bank term funding program |  |  |
BORROWINGS |  |  |
FHLB fixed rate advance (in percent) |  |  | 4.87%
Fixed rate FHLB term borrowings |  |  | $ 300.0
Secured Debt |  |  |
BORROWINGS |  |  |
Fixed rate FHLB term borrowings |  |  | 250.0
Revolving credit facility | Community Financial System Inc. |  |  |
BORROWINGS |  |  |
Maximum borrowing capacity |  | $ 50.0 |
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] |  | us-gaap:SecuredOvernightFinancingRateSofrMember |
Variable interest rate, basis spread |  | 2.25% |
Revolving credit facility | Subsequent events | Community Financial System Inc. |  |  |
BORROWINGS |  |  |
Line of credit facility, extension period | 364 days |  |
Debt Borrowing 50.0 Million Putable At Option of Lender | Secured Debt |  |  |
BORROWINGS |  |  |
Fixed rate FHLB term borrowings |  |  | $ 50.0
FHLB Term borrowings, Number of advances | item |  |  | 3
Debt Borrowing 50.0 Million Putable At Option of Lender | Secured Debt | Minimum |  |  |
BORROWINGS |  |  |
FHLB fixed rate advance (in percent) |  |  | 4.38%
Debt Borrowing 50.0 Million Putable At Option of Lender | Secured Debt | Maximum |  |  |
BORROWINGS |  |  |
FHLB fixed rate advance (in percent) |  |  | 4.47%
Debt Borrowing 100.0 Million Putable At Option of Lender | Secured Debt |  |  |
BORROWINGS |  |  |
FHLB fixed rate advance (in percent) |  |  | 3.73%
Fixed rate FHLB term borrowings |  |  | $ 100.0
FHLB Term borrowings, Number of advances | item |  |  | 1

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- Definition Period of extension available to the borrower after the the original maturity date, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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