Credit Quality and the Allowance for Loan and Lease Losses - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans in process of foreclosure amount	$ 94	$ 107
Financing receivable, excluding accrued interest, modified in period, amount	$ 552	$ 615
Loan modification program, percentage of modifications to total portfolio	0.46%	0.52%
Loan modification program, loans excluded from modification program	$ 52	$ 29
Unfunded commitment amounts	88	130
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, excluding accrued interest, modified in period, amount	$ 424	$ 453
Loan modification program, percentage of modifications to total portfolio	0.60%	0.62%
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, excluding accrued interest, modified in period, amount	$ 89	$ 113
Loan modification program, percentage of modifications to total portfolio	0.51%	0.66%
Modification program option, mortgage term	480 months
Modification program option, in-process modifications	$ 5	$ 3
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, excluding accrued interest, modified in period, amount	$ 39	$ 49
Loan modification program, percentage of modifications to total portfolio	0.13%	0.18%
Consumer | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, excluding accrued interest, modified in period, amount	$ 15	$ 16
Loan modification program, percentage of modifications to total portfolio	0.36%	0.41%
Modification program option, mortgage term	360 months
Minimum | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term extension period	3 months
Minimum | Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Modification program option, trial period	6 months
Modification program option, mortgage interest payment deferral, term	3 months
Maximum | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term extension period	12 months
Maximum | Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Modification program option, trial period	12 months
Modification program option, mortgage interest payment deferral, term	4 months