LOANS AND LEASES - Schedule of Loans by Class (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024	Sep. 30, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 144,758	$ 140,221	$ 138,695
Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	31,615	27,904
Investor dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2,772	3,193
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	116,428	111,993
Commercial | Commercial construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	5,926	5,109
Commercial | Owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	17,232	16,842
Commercial | Non-owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	15,645	16,194
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	41,172	40,737
Commercial | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2,066	2,014
Commercial | Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	31,615	27,904
Commercial | Investor dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2,772	3,193
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	28,330	28,228
Consumer | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	23,036	23,152
Consumer | Revolving mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2,794	2,567
Consumer | Consumer auto
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,463	1,523
Consumer | Consumer other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 1,037	$ 986