DERIVATIVES AND HEDGING ACTIVITIES - Classification on Consolidated Statements of Financial Condition (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($) DerivativeInstrument	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) DerivativeInstrument	Jun. 30, 2022 USD ($)	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	$ 2,437,000	$ 1,685,000	$ 5,570,000	$ 1,691,000
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	$ 16,611,000		$ 16,611,000		$ 17,150,000
Loan Level Interest Rate Swaps with Borrower (Assets) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, assets | DerivativeInstrument	23		23		3
Notional amount, assets	$ 275,552,000		$ 275,552,000		$ 53,311,000
Fair value assets	$ 4,874,000		$ 4,874,000		$ 1,524,000
Loan Level Interest Rate Swaps with Borrower (Liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	194		194		185
Notional amount, liabilities	$ 1,268,977,000		$ 1,268,977,000		$ 1,214,736,000
Fair value liabilities	122,618,000		122,618,000		$ 126,751,000
Posted collateral	$ 0		$ 0
Loan level interest rate floors with borrower (liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	33		33		40
Notional amount, liabilities	$ 226,257,000		$ 226,257,000		$ 326,309,000
Fair value liabilities	3,637,000		3,637,000		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	23		23		185
Notional amount, assets	$ 275,552,000		$ 275,552,000		$ 1,214,736,000
Fair value assets					126,751,000
Fair value liabilities	4,874,000		4,874,000
Posted collateral	0		0		0
Collateral received against obligations in net asset position	$ 122,700,000		$ 122,700,000		$ 135,300,000
Loan level interest rate swaps with third party counterparties (liabilities) | Not Designated as Hedging Instrument
Cash Flow Hedges
Count, liabilities | DerivativeInstrument	194		194		3
Notional amount, assets	$ 1,268,977,000		$ 1,268,977,000
Notional amount, liabilities					$ 53,311,000
Fair value assets	$ 122,618,000		$ 122,618,000
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	33		33		40
Notional amount, assets	$ 226,257,000		$ 226,257,000		$ 326,309,000
Fair value assets	$ 3,637,000		$ 3,637,000		$ 9,060,000