LOANS AND LEASES - Nonaccrual Loans by Loan Class (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	$ 156	$ 166
Total nonaccrual loans and leases	1,332	931
Commercial \| Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	117	76
Total nonaccrual loans and leases	824	562
Commercial \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	34	81
Total nonaccrual loans and leases	188	133
Commercial \| Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	2	4
Total nonaccrual loans and leases	9	8
Consumer \| Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	3	5
Total nonaccrual loans and leases	185	107
Consumer \| Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	0	0
Total nonaccrual loans and leases	6	6
Consumer \| Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	0	0
Total nonaccrual loans and leases	117	113
Consumer \| RV and marine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	0	0
Total nonaccrual loans and leases	2	2
Consumer \| Consumer loan portfolio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases with no ACL	0	0
Total nonaccrual loans and leases	$ 1	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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