CHANGE IN ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,589,752
Other comprehensive income (loss)	72,284	$ (46,536)
Less: Amounts reclassified from accumulated other comprehensive loss	3,119	3,620
Net current-period other comprehensive (loss) income	75,403	(42,916)
Ending balance	2,671,614
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(624,877)	(593,991)
Net current-period other comprehensive (loss) income	75,403	(42,916)
Ending balance	(549,474)	(636,907)
Net change in investment securities available-for-sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(537,789)	(499,932)
Other comprehensive income (loss)	70,037	(40,007)
Less: Amounts reclassified from accumulated other comprehensive loss	0	0
Net current-period other comprehensive (loss) income	70,037	(40,007)
Ending balance	(467,752)	(539,939)
Net change in investment securities held-to-maturity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(76,405)	(91,523)
Other comprehensive income (loss)	0	0
Less: Amounts reclassified from accumulated other comprehensive loss	3,188	3,669
Net current-period other comprehensive (loss) income	3,188	3,669
Ending balance	(73,217)	(87,854)
Net change in defined benefit plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,815)	(4,614)
Other comprehensive income (loss)	8	(75)
Less: Amounts reclassified from accumulated other comprehensive loss	(69)	(49)
Net current-period other comprehensive (loss) income	(61)	(124)
Ending balance	(3,876)	(4,738)
Net change in fair value of derivatives used for cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(7,297)	1,597
Other comprehensive income (loss)	2,875	(6,433)
Less: Amounts reclassified from accumulated other comprehensive loss	0	0
Net current-period other comprehensive (loss) income	2,875	(6,433)
Ending balance	(4,422)	(4,836)
Net change in equity method investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	429	481
Other comprehensive income (loss)	(636)	(21)
Less: Amounts reclassified from accumulated other comprehensive loss	0	0
Net current-period other comprehensive (loss) income	(636)	(21)
Ending balance	$ (207)	$ 460