DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Fair Value of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Designated as Hedging Instrument
Derivative [Line Items]
Assets	$ 3,730	$ 16,463
Liabilities	14,770	1,667
Designated as Hedging Instrument \| Cash flow hedges: \| Interest rate swaps, collars, and floors on loan pools
Derivative [Line Items]
Notional	3,200,000	2,300,000
Assets	2,717	11,627
Liabilities	14,770	1,667
Designated as Hedging Instrument \| Cash flow hedges: \| Interest rate swaps on borrowings
Derivative [Line Items]
Notional	50,000	50,000
Assets	0	0
Liabilities	0	0
Designated as Hedging Instrument \| Fair value hedges: \| Interest rate swaps on borrowings
Derivative [Line Items]
Notional	800,000	1,100,000
Assets	1,013	4,836
Liabilities	0	0
Designated as Hedging Instrument \| Fair value hedges: \| Interest rate swaps on investment securities
Derivative [Line Items]
Notional	874,407	927,407
Assets	0	0
Liabilities	0	0
Not Designated as Hedging Instrument
Derivative [Line Items]
Assets	144,122	154,365
Liabilities	250,908	257,301
Not Designated as Hedging Instrument \| Interest rate lock commitments
Derivative [Line Items]
Notional	117,675	81,698
Assets	493	583
Liabilities	0	0
Not Designated as Hedging Instrument \| Forward mortgage loan contracts
Derivative [Line Items]
Notional	134,702	120,584
Assets	0	0
Liabilities	223	402
Not Designated as Hedging Instrument \| Customer interest rate contracts
Derivative [Line Items]
Notional	10,605,993	9,939,577
Assets	26,627	76,026
Liabilities	223,791	180,367
Not Designated as Hedging Instrument \| Counterparty interest rate contracts
Derivative [Line Items]
Notional	10,605,993	9,939,577
Assets	116,780	77,597
Liabilities	26,798	76,442
Not Designated as Hedging Instrument \| Customer foreign currency contracts
Derivative [Line Items]
Notional	20,791	12,086
Assets	119	106
Liabilities	66	27
Not Designated as Hedging Instrument \| Counterparty foreign currency contracts
Derivative [Line Items]
Notional	20,645	11,656
Assets	103	53
Liabilities	$ 30	$ 63