DERIVATIVES AND HEDGING ACTIVITIES - Classification on Consolidated Statements of Financial Condition (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) DerivativeInstrument	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) DerivativeInstrument	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) DerivativeInstrument
Cash Flow Hedges
Collateral received against obligations in net asset position					$ 17,800,000
Not Designated as Hedging Instrument
Cash Flow Hedges
Loan level derivative income	$ 783,000	$ 549,000	$ 6,353,000	$ 2,240,000
Interest Rate Swaps Related to FHLBNY Advances | Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	4		4		4
Notional amount, assets	$ 150,000,000		$ 150,000,000		$ 150,000,000
Fair value assets	$ 16,657,000		$ 16,657,000		$ 17,150,000
Loan Level Interest Rate Swaps with Borrower (Assets) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	4		4		3
Notional amount, assets	$ 34,050,000		$ 34,050,000		$ 53,311,000
Fair value assets	$ 360,000		$ 360,000		$ 1,524,000
Loan Level Interest Rate Swaps with Borrower (Liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	219		219		185
Notional amount, liabilities	$ 1,549,816,000		$ 1,549,816,000		$ 1,214,736,000
Fair value liabilities	158,976,000		158,976,000		$ 126,751,000
Posted collateral	$ 0		$ 0
Loan level interest rate floors with borrower | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	3		3
Notional amount, assets	$ 17,625,000		$ 17,625,000
Loan level interest rate floors with borrower (liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	25		25		40
Notional amount, liabilities	$ 178,032,000		$ 178,032,000		$ 326,309,000
Fair value liabilities	1,376,000		1,376,000		9,060,000
Loan level interest rate swaps with third party counterparties (assets) | Designated as Hedging Instrument
Cash Flow Hedges
Posted collateral	$ 0		$ 0		$ 0
Loan level interest rate swaps with third party counterparties (assets) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument					185
Count, liabilities | DerivativeInstrument	219		219
Notional amount, assets	$ 1,549,816,000		$ 1,549,816,000		$ 1,214,736,000
Fair value assets	158,976,000		158,976,000		126,751,000
Posted collateral	0		0		0
Collateral received against obligations in net asset position	$ 167,600,000		$ 167,600,000		$ 135,300,000
Loan level interest rate swaps with third party counterparties (liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	4		4
Count, liabilities | DerivativeInstrument					3
Notional amount, assets	$ 34,050,000		$ 34,050,000
Notional amount, liabilities					$ 53,311,000
Fair value liabilities	$ 360,000		$ 360,000		$ 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
Loan level interest rate floors with third party counterparties | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	3		3
Notional amount, assets	$ 17,625,000		$ 17,625,000
Loan level interest rate floors with third party counterparties (liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	25		25
Notional amount, assets	$ 178,032,000		$ 178,032,000
Fair value assets	$ 1,376,000		$ 1,376,000