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