DERIVATIVES AND HEDGING ACTIVITIES - Fair value and cash flow hedge accounting on the consolidated statements of financial condition (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Designated as Hedging Instrument | Fair value hedges | Interest Rate Products
DERIVATIVES AND HEDGING ACTIVITIES
Notional amount, liabilities	$ 500,000	$ 500,000
Fair Value Liabilities	1,353	6,594
Designated as Hedging Instrument | Cash flow hedges | Interest Rate Products
DERIVATIVES AND HEDGING ACTIVITIES
Notional amount, assets	150,000	150,000
Notional amount, liabilities	200,000	200,000
Fair Value Assets	13,107	12,492
Fair Value Liabilities	1,067	5,031
Not Designated as Hedging Instrument | Interest Rate Products
DERIVATIVES AND HEDGING ACTIVITIES
Notional amount, assets	1,605,675	1,682,961
Notional amount, liabilities	1,605,675	1,682,961
Fair Value Assets	122,055	114,671
Fair Value Liabilities	122,055	114,671
Not Designated as Hedging Instrument | Other Contract
DERIVATIVES AND HEDGING ACTIVITIES
Notional amount, liabilities	93,726	93,891
Fair Value Liabilities	$ 8	$ 24