Loans and Leases - Modifications to Borrowers Experiencing Financial Difficulty (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 1
% of Total Class	0.00%	0.00%
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 123	$ 120
% of Total Class	0.20%	0.20%
Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 1
% of Total Class	0.00%	0.00%
Payment Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 3
% of Total Class	0.00%	0.00%
Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 3	$ 3
% of Total Class	0.00%	0.00%
Combination - Term Extension, Interest Rate Reduction, and Interest Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 2
% of Total Class	0.00%	0.00%
Combination - Term Extension, Interest Rate Reduction, and Interest Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 17
% of Total Class	0.00%	0.00%
Consumer: | Consumer Real Estate | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 1
% 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	9.87%	8.70%
Consumer: | Consumer Real Estate | Interest Rate Reduction | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	6.52%	3.60%
Consumer: | Consumer Real Estate | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 1
% of Total Class	0.00%	0.00%
Weighted average life of loans	22 years	13 years
Consumer: | Consumer Real Estate | Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 1
% of Total Class	0.00%	0.00%
Decrease from loan modification	$ 1	$ 1
Amount in accordance with original loan terms		1
Consumer: | Consumer Real Estate | Payment Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 3
% of Total Class	0.00%	0.00%
Weighted average life of loans		11 months
Consumer: | Consumer Real Estate | Combination - Term Extension and Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 3	$ 3
% of Total Class	0.00%	0.00%
Weighted average life of loans	10 years 9 months 18 days	13 years 1 month 6 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	8.39%	5.40%
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	3.67%	3.90%
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	5.77%	14.70%
Consumer: | Credit Card and Other | Interest Rate Reduction | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans	4.41%	0.00%
Commercial: | Commercial and industrial | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 95	$ 73
% of Total Class	0.30%	0.20%
Weighted average life of loans	1 year 2 months 12 days	1 year
Commercial: | Commercial and industrial | Combination - Principal Forgiveness, Term Extension, and Payment Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 16
% of Total Class	0.00%	0.00%
Weighted average life of loans		6 years 2 months 12 days
Decrease from loan modification		$ 2
Commercial: | Commercial and industrial | Combination - Term Extension, Interest Rate Reduction, and Interest Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 2
% of Total Class	0.00%	0.00%
Weighted average life of loans		3 years 8 months 12 days
Decrease from loan modification		$ 1
Commercial: | Commercial and industrial | Combination - Term Extension, Interest Rate Reduction, and Interest Forgiveness | Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans		11.30%
Commercial: | Commercial and industrial | Combination - Term Extension, Interest Rate Reduction, and Interest Forgiveness | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans		7.50%
Commercial: | Commercial real estate | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 28	$ 46
% of Total Class	0.20%	0.30%
Weighted average life of loans	2 years 4 months 24 days	1 year
Commercial: | Commercial real estate | Combination - Term Extension, Interest Rate Reduction, and Interest Deferrals
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance	$ 0	$ 17
% of Total Class	0.00%	0.00%
Weighted average life of loans		1 year
Decrease from loan modification		$ 1
Commercial: | Commercial real estate | Combination - Term Extension, Interest Rate Reduction, and Interest Deferrals | Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans		8.70%
Commercial: | Commercial real estate | Combination - Term Extension, Interest Rate Reduction, and Interest Deferrals | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted average interest rate of loans		8.00%