LOANS AND LEASES - Summary of Loans and Leases Portfolio (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 142,692	$ 139,203
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	73,812	69,776
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	49,232	42,551
Commercial | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	24,580	27,225
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	68,880	69,427
Retail | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	35,024	32,726
Retail | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	19,069	16,495
Retail | Automobile
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	2,310	4,744
Retail | Education
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	8,416	10,812
Retail | Other retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 4,061	$ 4,650