DERIVATIVES - Summary of Derivative Financial Instruments and Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 20,305,538	$ 19,828,103
Derivative Asset	301,938	357,698
Derivative liabilities	301,938	357,698
Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral	(39,838)	(58,295)
Gross amounts of recognized liabilities	301,938	357,698
Derivative Liability, Fair Value, Gross Asset	(341,776)	(415,993)
Fair Value Hedges | Matched interest rate swaps | Accrued interest and other assets
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,248,403	2,206,351
Derivative Asset	10,458	5,057
Derivative liabilities	114,269	147,759
Fair Value Hedges | Matched interest rate swaps | Accrued interest and other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,248,403	2,206,351
Derivative Asset	114,269	147,759
Derivative liabilities	10,458	5,057
Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral	(127,424)	(161,232)
Gross amounts of recognized liabilities	124,727	152,816
Derivative Liability, Fair Value, Gross Asset	(252,151)	(314,048)
Foreign Exchange | Matched interest rate swaps | Accrued interest and other assets
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	7,927,466	7,734,395
Derivative Asset	99,348	111,078
Derivative liabilities	77,863	93,804
Foreign Exchange | Matched interest rate swaps | Accrued interest and other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	7,881,266	7,681,006
Derivative Asset	77,863	93,804
Derivative liabilities	$ 99,348	$ 111,078