Loans and Leases - Loan Modifications to Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 46	$ 0
% of Total Class	0.10%	0.00%
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 281	$ 227
% of Total Class	0.40%	0.40%
Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 1	$ 0
% of Total Class	0.00%	0.00%
Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 35	$ 3
% of Total Class	0.10%	0.00%
Commercial: \| Commercial real estate \| Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 46	$ 0
% of Total Class	0.30%	0.00%
Commercial: \| Commercial real estate \| Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	7.80%
Commercial: \| Commercial real estate \| Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	7.13%
Commercial: \| Commercial real estate \| Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 142	$ 116
% of Total Class	1.00%	0.80%
Weighted average life of loans	1 year 3 months 18 days	1 year 6 months
Commercial: \| Commercial real estate \| Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 33	$ 0
% of Total Class	0.20%	0.00%
Weighted average life of loans	2 years
Commercial: \| Commercial real estate \| Combination - Term Extension and Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	7.81%
Commercial: \| Commercial real estate \| Combination - Term Extension and Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	6.86%
Commercial: \| Commercial and industrial \| Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 139	$ 111
% of Total Class	0.40%	0.30%
Weighted average life of loans	1 year 1 month 6 days	1 year 4 months 24 days
Commercial: \| Commercial and industrial \| Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0
% of Total Class	0.00%	0.00%
Weighted average life of loans	1 year 2 months 12 days
Commercial: \| Commercial and industrial \| Combination - Term Extension and Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	9.37%
Commercial: \| Commercial and industrial \| Combination - Term Extension and Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	8.33%
Consumer: \| Consumer Real Estate \| Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0
% of Total Class	0.00%	0.00%
Consumer: \| Consumer Real Estate \| Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	9.62%	9.93%
Consumer: \| Consumer Real Estate \| Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	5.46%	6.56%
Consumer: \| Consumer Real Estate \| Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0
% of Total Class	0.00%	0.00%
Weighted average life of loans	10 years	22 years
Consumer: \| Consumer Real Estate \| Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 1	$ 0
% of Total Class	0.00%	0.00%
Decrease from loan modification (less than)	$ 1	$ 1
Consumer: \| Consumer Real Estate \| Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 2	$ 3
% of Total Class	0.00%	0.00%
Weighted average life of loans	15 years 2 months 12 days	10 years 10 months 24 days
Consumer: \| Consumer Real Estate \| Combination - Term Extension and Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	7.47%	8.66%
Consumer: \| Consumer Real Estate \| Combination - Term Extension and Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	3.76%	4.06%
Consumer: \| Credit Card and Other \| Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 0
% of Total Class	0.00%	0.00%
Consumer: \| Credit Card and Other \| Interest Rate Reduction \| Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	14.90%	4.78%
Consumer: \| Credit Card and Other \| Interest Rate Reduction \| Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	0.00%	3.65%

Amount of increase (decrease) in amortized cost excluding accrued interest, of financing receivable modified for debtor experiencing financial difficulty.

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-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
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