COMMITMENTS AND CONTINGENCIES - Loan and Unfunded Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Other Commitments [Line Items]
Unused Commitments to Extend Credit	$ 4,660,934	$ 4,467,728
Gross loans and leases, excluding accrued interest	13,494,841	13,424,070
Commercial
Other Commitments [Line Items]
Unused Commitments to Extend Credit	2,153,967	2,066,620
Gross loans and leases, excluding accrued interest	4,693,786	4,632,241
Lease financing
Other Commitments [Line Items]
Unused Commitments to Extend Credit	0	0
Gross loans and leases, excluding accrued interest	649,645	638,527
Construction real estate
Other Commitments [Line Items]
Unused Commitments to Extend Credit	711,584	680,920
Gross loans and leases, excluding accrued interest	591,080	677,339
Commercial real estate - investor
Other Commitments [Line Items]
Unused Commitments to Extend Credit	202,341	204,747
Gross loans and leases, excluding accrued interest	3,318,301	3,246,889
Commercial real estate-owner
Other Commitments [Line Items]
Unused Commitments to Extend Credit	36,996	39,973
Gross loans and leases, excluding accrued interest	1,155,167	1,137,667
Residential real estate
Other Commitments [Line Items]
Unused Commitments to Extend Credit	0	0
Gross loans and leases, excluding accrued interest	1,831,338	1,832,184
Home equity
Other Commitments [Line Items]
Unused Commitments to Extend Credit	1,171,062	1,103,581
Gross loans and leases, excluding accrued interest	1,026,839	1,005,204
Installment
Other Commitments [Line Items]
Unused Commitments to Extend Credit	57,442	48,606
Gross loans and leases, excluding accrued interest	162,314	188,694
Credit card
Other Commitments [Line Items]
Unused Commitments to Extend Credit	327,542	323,281
Gross loans and leases, excluding accrued interest	$ 66,371	$ 65,325