LOANS, LEASES, AND ALLOWANCE FOR CREDIT LOSSES (Summary of Major Portfolio Segment and Specific Loan Class) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans held for sale	$ 201	$ 74
Total loans and leases	60,917	59,410
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	31,696	30,965
Commercial \| Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	17,761	16,891
Commercial \| Owner-occupied
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	9,274	9,333
Commercial \| Municipal
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	4,294	4,364
Commercial \| Leasing
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	367	377
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	13,396	13,477
Commercial real estate \| Term
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	11,234	10,703
Commercial real estate \| Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	2,162	2,774
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	15,825	14,968
Consumer \| 1-4 family residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	10,462	9,939
Consumer \| Home equity credit line
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	3,950	3,641
Consumer \| Construction and other consumer real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	782	810
Consumer \| Bankcard and other revolving plans
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	515	457
Consumer \| Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans and leases	$ 116	$ 121