DERIVATIVES - Summary of Derivative Financial Instruments and Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 18,504,223	$ 19,339,867
Derivative Asset	295,131	269,776
Derivative liabilities	(293,926)	(263,131)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	17,504,223	18,339,867
Derivative Asset	293,566	262,880
Derivative liabilities	(293,756)	(263,131)
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,000,000	1,000,000
Derivative Asset	1,565	6,896
Derivative liabilities	(170)	0
Fair Value Hedges | Matched interest rate swaps | Accrued interest and other assets | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,202,947	2,172,714
Derivative Asset	8,012	13,232
Derivative liabilities	(123,248)	(104,343)
Fair Value Hedges | Matched interest rate swaps | Accrued interest and other liabilities | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,202,947	2,172,714
Derivative Asset	123,058	104,092
Derivative liabilities	(8,012)	(13,232)
Foreign Exchange | Matched interest rate swaps | Accrued interest and other assets | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,571,536	7,021,569
Derivative Asset	99,421	84,731
Derivative liabilities	(63,075)	(60,825)
Foreign Exchange | Matched interest rate swaps | Accrued interest and other liabilities | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,526,793	6,972,870
Derivative Asset	63,075	60,825
Derivative liabilities	$ (99,421)	$ (84,731)
Cash Flow Hedging | Interest Rate Floor | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Cash Flow Hedging | Interest Rate Floor | Accrued interest and other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 1,000,000
Cash Flow Hedging | Interest Rate Floor | Accrued interest and other liabilities | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 1,000,000	$ 1,000,000