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DERIVATIVES AND HEDGING ACTIVITIES - Classification on Consolidated Statements of Financial Condition (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) DerivativeInstrument	Dec. 31, 2020 USD ($) DerivativeInstrument	Dec. 31, 2019 USD ($)
Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Loan level derivative income	$ 2,909,000	$ 8,872,000	$ 910,000
Interest Rate Swaps Related to FHLBNY Advances [Member] \| Designated as Hedging Instrument
Cash Flow Hedges
Count, assets \| DerivativeInstrument	4
Count, liabilities \| DerivativeInstrument		32
Notional amount, assets	$ 150,000,000
Notional amount, liabilities		$ 655,000,000
Fair value assets	$ 4,358,000
Fair value liabilities		$ (18,442,000)
Loan Level Interest Rate Swaps with Borrower (Assets) \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument	111	65
Notional amount, assets	$ 604,529,000	$ 570,277,000
Fair value assets	$ 28,291,000	$ 24,764,000
Loan Level Interest Rate Swaps with Borrower (Liabilities) \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument	74
Notional amount, liabilities	$ 620,459,000
Fair value liabilities	(11,865,000)
Posted collateral	$ 0
Loan Level Interest Rate Floors with Borrower [Member] \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument	45	41
Notional amount, liabilities	$ 392,764,000	$ 364,643,000
Fair value liabilities	(5,644,000)	(5,832,000)
Loan Level Interest Rate Swaps with Third-part Counterparties [Member] \| Designated as Hedging Instrument
Cash Flow Hedges
Posted collateral	$ 0	$ 5,400,000
Loan Level Interest Rate Swaps with Third-part Counterparties [Member] \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, liabilities \| DerivativeInstrument	111	65
Notional amount, liabilities	$ 604,529,000	$ 570,277,000
Fair value liabilities	(28,291,000)	$ (24,764,000)
Posted collateral	$ 14,000,000.0
Loan level interest rate swaps with third party counterparties (Assets) \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument	74
Notional amount, assets	$ 620,459,000
Fair value assets	$ 11,865,000
Loan Level Interest Rate Floors with Third-part Counterparties [Member] \| Not Designated as Hedging Instrument [Member]
Cash Flow Hedges
Count, assets \| DerivativeInstrument	45	41
Notional amount, assets	$ 392,764,000	$ 364,643,000
Fair value assets	$ 5,644,000	$ 5,832,000