Loans and Leases - Performance of Loans that have been Modified in the Last 12 Months (Details) $ in Millions	Jun. 30, 2025 USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-Accruing	$ 176
Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	375
30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	8
90+ Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Commercial: | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-Accruing	27
Commercial: | Commercial and industrial | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	127
Commercial: | Commercial and industrial | 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	8
Commercial: | Commercial and industrial | 90+ Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Commercial: | Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-Accruing	148
Commercial: | Commercial real estate | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	247
Commercial: | Commercial real estate | 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Commercial: | Commercial real estate | 90+ Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Consumer: | Consumer Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-Accruing	1
Consumer: | Consumer Real Estate | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	1
Consumer: | Consumer Real Estate | 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Consumer: | Consumer Real Estate | 90+ Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	$ 0