DERIVATIVES - Fair Values of Derivatives Reported on Condensed Consolidated Statements of Financial Condition (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	$ 5,087	$ 3,533
Derivative assets, amounts not netted: cash collateral	0	0
Derivative assets, amounts not netted, securities collateral	0	0
Derivative assets, fair value, total	4,879	2,789
Derivative assets, notional amount	308,023	288,113
Derivative liabilities, fair value	283,037	379,557
Derivative liabilities, amounts not netted: cash collateral	(546)	(243)
Derivative liabilities, amounts not netted: securities collateral	0	0
Derivative liabilities, fair value, total	273,487	368,430
Derivative liabilities, notional	529,934	640,734
Forward foreign currency exchange rate contracts
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	4,955	3,400
Derivative assets, fair value, counterparty and cash collateral netting	(77)	(604)
Derivative assets, notional amount	294,029	283,635
Derivative liabilities, fair value	1,739	1,847
Derivative liabilities, fair value, counterparty and cash collateral netting	(77)	(603)
Derivative liabilities, notional	147,889	170,704
Total return swaps and other
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	132	133
Derivative assets, fair value, counterparty and cash collateral netting	(131)	(140)
Derivative assets, notional amount	13,994	4,478
Derivative liabilities, fair value	11,081	12,290
Derivative liabilities, fair value, counterparty and cash collateral netting	(8,927)	(10,281)
Derivative liabilities, notional	122,971	117,139
LFI and other similar deferred compensation arrangements
Derivatives, Fair Value [Line Items]
Derivative assets, fair value	0	0
Derivative assets, notional amount	0	0
Derivative liabilities, fair value	270,217	365,420
Derivative liabilities, notional	259,074	352,891
Net derivatives in "other assets" and "other liabilities"
Derivatives, Fair Value [Line Items]
Derivative assets, net derivatives	4,879	2,789
Derivative liabilities, net derivatives	$ 274,033	$ 368,673