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DERIVATIVES AND HEDGING ACTIVITIES - Classification on Consolidated Statements of Financial Condition (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 USD ($) DerivativeInstrument | Dec. 31, 2022 USD ($) DerivativeInstrument | Dec. 31, 2021 USD ($) | Oct. 31, 2023 USD ($)
Cash Flow Hedges |  |  |  |
Collateral received against obligations in net asset position | $ 13,500,000 | $ 17,800,000 |  |
Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Loan level derivative income | 7,081,000 | 3,637,000 | $ 2,909,000 |
Interest Rate Products | Designated as Hedging Instrument | Cash flow hedges |  |  |  |
Cash Flow Hedges |  |  |  |
Notional amount, assets | 150,000,000 | 150,000,000 |  |
Notional amount, liabilities | 200,000,000 |  |  |
Fair value assets | 12,492,000 | 17,874,000 |  |
Interest Rate Products | Designated as Hedging Instrument | Fair value hedges |  |  |  |
Cash Flow Hedges |  |  |  |
Notional amount, liabilities | 500,000,000 |  |  |
Interest Rate Products | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Notional amount, assets | 1,682,961,000 | 1,594,356,000 |  |
Notional amount, liabilities | 1,682,961,000 | 1,594,356,000 |  |
Fair value assets | $ 114,671,000 | $ 137,335,000 |  |
Interest Rate Swaps | Designated as Hedging Instrument | Fair value hedges |  |  |  |
Cash Flow Hedges |  |  |  |
Notional amount, liabilities |  |  |  | $ 500,000,000.0
Loan Level Interest Rate Swaps with Borrower (Assets) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, assets | DerivativeInstrument | 49 | 3 |  |
Notional amount, assets | $ 491,394,000 | $ 53,311,000 |  |
Fair value assets | $ 10,985,000 | $ 1,524,000 |  |
Loan Level Interest Rate Swaps with Borrower (Liabilities) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, liabilities | DerivativeInstrument | 178 | 185 |  |
Notional amount, liabilities | $ 1,121,085,000 | $ 1,214,736,000 |  |
Fair value liabilities | 103,570,000 | $ 126,751,000 |  |
Posted collateral | $ 0 |  |  |
Loan level interest rate floors with borrower | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, assets | DerivativeInstrument | 2 |  |  |
Notional amount, assets | $ 29,721,000 |  |  |
Loan level interest rate floors with borrower (liabilities) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, liabilities | DerivativeInstrument | 7 | 40 |  |
Notional amount, liabilities | $ 40,761,000 | $ 326,309,000 |  |
Fair value liabilities | $ 116,000 | $ 9,060,000 |  |
Loan level interest rate swaps with third party counterparties (assets) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, assets | DerivativeInstrument | 178 | 185 |  |
Count, liabilities | DerivativeInstrument | 49 |  |  |
Notional amount, assets | $ 1,121,085,000 | $ 1,214,736,000 |  |
Notional amount, liabilities | 491,394,000 |  |  |
Fair value assets | 103,570,000 | 126,751,000 |  |
Fair value liabilities | 10,985,000 |  |  |
Posted collateral | 0 | 0 |  |
Collateral received against obligations in net asset position |  | $ 135,300,000 |  |
Loan level interest rate swaps with third party counterparties (liabilities) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, liabilities | DerivativeInstrument |  | 3 |  |
Notional amount, liabilities |  | $ 53,311,000 |  |
Fair value liabilities |  | $ 1,524,000 |  |
Loan level interest rate floors with third party counterparties (assets) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, assets | DerivativeInstrument |  | 40 |  |
Notional amount, assets |  | $ 326,309,000 |  |
Fair value assets |  | $ 9,060,000 |  |
Collateral received against obligations in net asset position | $ 94,700,000 |  |  |
Loan level interest rate floors with third party counterparties | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, liabilities | DerivativeInstrument | 2 |  |  |
Notional amount, assets | $ 29,721,000 |  |  |
Loan level interest rate floors with third party counterparties (liabilities) | Not Designated as Hedging Instrument |  |  |  |
Cash Flow Hedges |  |  |  |
Count, assets | DerivativeInstrument | 7 |  |  |
Notional amount, assets | $ 40,761,000 |  |  |
Fair value assets | $ 116,000 |  |  |
Posted collateral |  |  | $ 14,000,000.0 |

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