Fair Value of Assets and Liabilities - Schedule Of Unobservable Inputs Utilized In Determining The Fair Value Of Level 3 Recurring And Non-Recurring Measurements (Details) $ in Millions	Dec. 31, 2023 USD ($) month	Dec. 31, 2022 USD ($) month
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale	$ 68	$ 51
Derivative liabilities, other	675	929
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities, other	23	27
Loans net of unearned income	245	135
OREO, fair value	4	3
Level 3 | Interest-only strips
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	13	25
Level 3 | Loans Held For Sale, Residential Real Estate | Residential Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale	26	22
Level 3 | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	$ 90	$ 91
Constant prepayment rate | Level 3 | Interest-only strips | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.14	0.12
Constant prepayment rate | Level 3 | Interest-only strips | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.15	0.13
Constant prepayment rate | Level 3 | Interest-only strips | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.14	0.12
Bond equivalent yield | Level 3 | Interest-only strips | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.18	0.17
Bond equivalent yield | Level 3 | Interest-only strips | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.21
Bond equivalent yield | Level 3 | Interest-only strips | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.18	0.17
Prepayment speeds - First mortgage | Level 3 | Loans Held For Sale, Residential Real Estate | First Mortgages | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.02	0.02
Prepayment speeds - First mortgage | Level 3 | Loans Held For Sale, Residential Real Estate | First Mortgages | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.07	0.08
Prepayment speeds - First mortgage | Level 3 | Loans Held For Sale, Residential Real Estate | First Mortgages | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.03	0.03
Foreclosure losses | Level 3 | Loans Held For Sale, Residential Real Estate | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.64	0.63
Foreclosure losses | Level 3 | Loans Held For Sale, Residential Real Estate | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.68	0.75
Foreclosure losses | Level 3 | Loans Held For Sale, Residential Real Estate | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.65	0.65
Loss severity trends - First mortgage | Level 3 | Loans Held For Sale, Residential Real Estate | First Mortgages | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0	0
Loss severity trends - First mortgage | Level 3 | Loans Held For Sale, Residential Real Estate | First Mortgages | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.03	0.11
Loss severity trends - First mortgage | Level 3 | Loans Held For Sale, Residential Real Estate | First Mortgages | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.02	0.05
Visa covered litigation resolution amount | Level 3 | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input, value	$ 5,700	$ 6,000
Visa covered litigation resolution amount | Level 3 | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input, value	6,700	5,600
Visa covered litigation resolution amount | Level 3 | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input, value	$ 6,300	$ 5,900
Probability of resolution scenarios | Level 3 | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.10	0.05
Probability of resolution scenarios | Level 3 | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.25	0.25
Probability of resolution scenarios | Level 3 | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.18	0.20
Time until resolution | Level 3 | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | month	6	12
Time until resolution | Level 3 | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | month	36	42
Time until resolution | Level 3 | Weighted Average | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | month	24	28
Marketability adjustments for specific properties | Level 3 | Minimum | Appraisals from comparable properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0	0
Marketability adjustments for specific properties | Level 3 | Maximum | Appraisals from comparable properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.25	0.10
Marketability adjustments for specific properties | Level 3 | Other Assets | Minimum | Appraisals from comparable properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0	0
Marketability adjustments for specific properties | Level 3 | Other Assets | Maximum | Appraisals from comparable properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0.25	0.25
Borrowing base certificates liquidation adjustment | Level 3 | Minimum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.25	0.20
Borrowing base certificates liquidation adjustment | Level 3 | Maximum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.50	0.50
Financial Statements/Auction values adjustment | Level 3 | Minimum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input		0
Financial Statements/Auction values adjustment | Level 3 | Maximum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input		0.25
Financial Statements liquidation adjustment | Level 3 | Minimum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.50
Financial Statements liquidation adjustment | Level 3 | Maximum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	1
Auction appraisals marketability adjustment | Level 3 | Minimum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0
Auction appraisals marketability adjustment | Level 3 | Maximum | Other collateral valuations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.10
Adjustment for value changes since appraisal | Level 3 | Minimum | Appraisals from comparable properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
OREO measurement input	0	0
Adjustment for value changes since appraisal | Level 3 | Maximum | Appraisals from comparable properties
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
OREO measurement input	0.10	0.10
Adjustments to current sales yields for specific properties | Level 3 | Other Assets | Minimum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0	0
Adjustments to current sales yields for specific properties | Level 3 | Other Assets | Maximum | Discounted cash flow
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0.15	0.15