Loans and Leases - Performance Of Loans That Have Been Modified In The Last 12 Months (Details) $ in Millions	Sep. 30, 2023 USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-Accruing	$ 66
Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	87
30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
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	6
Commercial: | Commercial and industrial | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	77
Commercial: | Commercial and industrial | 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
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	50
Commercial: | Commercial real estate | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	8
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	10
Consumer: | Consumer Real Estate | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	2
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
Consumer: | Credit Card and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-Accruing	0
Consumer: | Credit Card and Other | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Consumer: | Credit Card and Other | 30-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	0
Consumer: | Credit Card and Other | 90+ Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans	$ 0