BORROWED FUNDS - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2024
Borrowed Funds [Line Items]
FHLB, amount of available, unused funds	$ 2,051,000	$ 1,984,000
Borrowed funds	390,000	210,000
Bank Term Funding Program
Borrowed Funds [Line Items]
Borrowed funds	390,000	0
FHLB advances
Borrowed Funds [Line Items]
Borrowed funds	0	210,000
Asset Pledged as Collateral | Bank Term Funding Program
Borrowed Funds [Line Items]
Financial instruments, owned, at fair value	362,400
Financial instruments owned at par value	$ 398,100
Asset Pledged as Collateral | FHLB advances
Borrowed Funds [Line Items]
Financial instruments, owned, at fair value		$ 4,265,000
Minimum
Borrowed Funds [Line Items]
FHLB interest rate		4.50%
Minimum | Bank Term Funding Program
Borrowed Funds [Line Items]
Interest rate, short-term debt	4.69%
Maximum
Borrowed Funds [Line Items]
FHLB interest rate		4.56%
Maximum | Bank Term Funding Program
Borrowed Funds [Line Items]
Interest rate, short-term debt	4.83%