COMMITMENTS AND CONTINGENCIES - Loan and Unfunded Commitments (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Other Commitments [Line Items]
Unused Commitments to Extend Credit	$ 4,074,151	$ 3,750,657
Gross loans and leases, excluding accrued interest	11,714,551	11,761,778
Commercial
Other Commitments [Line Items]
Unused Commitments to Extend Credit	1,932,137	1,887,965
Gross loans and leases, excluding accrued interest	3,838,630	3,815,858
Lease financing
Other Commitments [Line Items]
Unused Commitments to Extend Credit	0	0
Gross loans and leases, excluding accrued interest	596,734	598,045
Construction real estate
Other Commitments [Line Items]
Unused Commitments to Extend Credit	509,759	327,743
Gross loans and leases, excluding accrued interest	627,960	779,446
Commercial real estate - investor
Other Commitments [Line Items]
Unused Commitments to Extend Credit	184,202	95,810
Gross loans and leases, excluding accrued interest	3,052,134	3,093,384
Commercial real estate-owner
Other Commitments [Line Items]
Unused Commitments to Extend Credit	38,501	40,791
Gross loans and leases, excluding accrued interest	996,236	968,360
Residential real estate
Other Commitments [Line Items]
Unused Commitments to Extend Credit	0	76,401
Gross loans and leases, excluding accrued interest	1,494,464	1,462,284
Home equity
Other Commitments [Line Items]
Unused Commitments to Extend Credit	1,061,179	1,002,965
Gross loans and leases, excluding accrued interest	935,975	849,039
Installment
Other Commitments [Line Items]
Unused Commitments to Extend Credit	27,590	33,200
Gross loans and leases, excluding accrued interest	109,764	133,051
Credit card
Other Commitments [Line Items]
Unused Commitments to Extend Credit	320,783	285,782
Gross loans and leases, excluding accrued interest	$ 62,654	$ 62,311