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DERIVATIVES AND HEDGING ACTIVITIES - Classification on Consolidated Statements of Financial Condition (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) DerivativeInstrument	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) DerivativeInstrument	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) DerivativeInstrument
Cash Flow Hedges
Collateral received against obligations in net asset position					$ 4,600,000
Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Loan level derivative income	$ 549,000	$ 445,000	$ 2,240,000	$ 2,796,000
Interest Rate Swaps Related to FHLBNY Advances [Member] \| 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	$ 18,336,000		$ 18,336,000		$ 4,358,000
Loan Level Interest Rate Swaps with Borrower (Assets) \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument					98
Notional amount, assets					$ 599,003,000
Fair value assets					$ 27,440,000
Loan Level Interest Rate Swaps with Borrower (Liabilities) \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument	187		187
Notional amount, liabilities	$ 1,225,306,000		$ 1,225,306,000
Fair value liabilities	(133,938,000)		(133,938,000)
Posted collateral	$ 0		$ 0
Loan Level Interest Rate Swaps with Borrower 3 \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument					87
Notional amount, liabilities					$ 612,610,000
Fair value liabilities					$ (12,620,000)
Loan Level Interest Rate Floors with Borrower \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument	41		41		12
Notional amount, liabilities	$ 328,864,000		$ 328,864,000		$ 100,774,000
Fair value liabilities	(10,405,000)		(10,405,000)		$ (53,000)
Loan Level Interest Rate Floors with Borrower 2 \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument					33
Notional amount, assets					$ 291,990,000
Fair value assets					$ 615,000
Loan Level Interest Rate Swaps with Third-part Counterparties 2 \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument					98
Notional amount, liabilities					$ 599,003,000
Fair value liabilities					(27,440,000)
Loan Level Interest Rate Swaps with Third-part Counterparties \| Designated as Hedging Instrument
Cash Flow Hedges
Posted collateral	$ 0		$ 0		$ 0
Loan Level Interest Rate Swaps with Third-part Counterparties \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument					87
Count, liabilities \| DerivativeInstrument	187		187
Notional amount, assets	$ 1,225,306,000		$ 1,225,306,000		$ 612,610,000
Fair value assets	133,938,000		133,938,000		12,620,000
Posted collateral	0		0		$ 14,000,000.0
Loan level interest rate swaps with third party counterparties (Assets) \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Posted collateral	$ 140,000,000.0		$ 140,000,000.0
Loan Level Interest Rate Floors with Third-part Counterparties \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument	41		41		33
Notional amount, assets	$ 328,864,000		$ 328,864,000
Notional amount, liabilities					$ 291,990,000
Fair value assets	$ 10,405,000		$ 10,405,000
Fair value liabilities					$ (615,000)
Loan Level Interest Rate Floors with Third-part Counterparties 2 \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument					12
Notional amount, assets					$ 100,774,000
Fair value assets					$ 53,000