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, 2021 USD ($) month	Dec. 31, 2020 USD ($) month	Dec. 31, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale	$ 258	$ 405
Derivative liabilities, other	103	125
Non Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	30	9	$ 11
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities, other	23	14
Loans net of unearned income	84	77
OREO, fair value	3	15
Level 3 | Non Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	30	9	$ 11
Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale		1
Loans Held For Sale - SBA | Level 3 | Small Business Administrations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale	1
Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment		16
Other Assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	$ 30	$ 9
Constant prepayment rate | Minimum | Discounted cash flow | Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.08
Constant prepayment rate | Minimum | Discounted cash flow | Loans Held For Sale - SBA | Level 3 | Small Business Administrations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.08
Constant prepayment rate | Minimum | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0
Constant prepayment rate | Maximum | Discounted cash flow | Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.12
Constant prepayment rate | Maximum | Discounted cash flow | Loans Held For Sale - SBA | Level 3 | Small Business Administrations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.12
Constant prepayment rate | Maximum | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.26
Constant prepayment rate | Weighted Average | Discounted cash flow | Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.10
Constant prepayment rate | Weighted Average | Discounted cash flow | Loans Held For Sale - SBA | Level 3 | Small Business Administrations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.10
Constant prepayment rate | Weighted Average | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.11
Bond equivalent yield | Discounted cash flow | Loans Held For Sale - SBA | Level 3 | Small Business Administrations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.11
Bond equivalent yield | Minimum | Discounted cash flow | Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.07
Bond equivalent yield | Maximum | Discounted cash flow | Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.08
Bond equivalent yield | Weighted Average | Discounted cash flow | Loans Held For Sale - SBA | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.07
Bond equivalent yield | Weighted Average | Discounted cash flow | Loans Held For Sale - SBA | Level 3 | Small Business Administrations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.11
Foreclosure losses | Minimum | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.54	0.59
Foreclosure losses | Maximum | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.66	0.70
Foreclosure losses | Weighted Average | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.65	0.63
Loss severity trends - First mortgage | Minimum | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0
Loss severity trends - First mortgage | Maximum | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		1
Loss severity trends - First mortgage | Weighted Average | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.11
Constant default rate | Minimum | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0
Constant default rate | Maximum | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.14
Constant default rate | Weighted Average | Discounted cash flow | Loans held for investment | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input		0.01
Visa covered litigation resolution amount | Minimum | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input, value	$ 5,800	$ 6,000
Visa covered litigation resolution amount | Maximum | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input, value	6,200	5,400
Visa covered litigation resolution amount | Weighted Average | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input, value	$ 6,000	$ 5,800
Probability of resolution scenarios | Minimum | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.15	0.10
Probability of resolution scenarios | Maximum | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.35	0.50
Probability of resolution scenarios | Weighted Average | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input	0.24	0.16
Time until resolution | Minimum | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | month	12	3
Time until resolution | Maximum | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | month	36	27
Time until resolution | Weighted Average | Discounted cash flow | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, measurement input | month	25	19
Marketability adjustments for specific properties | Minimum | Appraisals from comparable properties | Level 3
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 | Minimum | Appraisals from comparable properties | Other Assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0	0
Marketability adjustments for specific properties | Maximum | Appraisals from comparable properties | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.10	0.10
Marketability adjustments for specific properties | Maximum | Appraisals from comparable properties | Other Assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0.25	0.25
Borrowing base certificates adjustment | Minimum | Other collateral valuations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.20	0.20
Borrowing base certificates adjustment | Maximum | Other collateral valuations | Level 3
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 | Minimum | Other collateral valuations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0	0
Financial Statements/Auction values adjustment | Maximum | Other collateral valuations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans net of unearned income, measurement input	0.25	0.25
Adjustment for value changes since appraisal | Minimum | Appraisals from comparable properties | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
OREO measurement input	0	0
Adjustment for value changes since appraisal | Maximum | Appraisals from comparable properties | Level 3
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 | Minimum | Discounted cash flow | Other Assets | Level 3
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 | Maximum | Discounted cash flow | Other Assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, measurement input	0.15	0.15
Residential Real Estate | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale	$ 29	$ 13
First Mortgages | Prepayment speeds - First mortgage | Minimum | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.04	0.05
First Mortgages | Prepayment speeds - First mortgage | Maximum | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.12	0.15
First Mortgages | Prepayment speeds - First mortgage | Weighted Average | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.05	0.05
First Mortgages | Loss severity trends - First mortgage | Minimum | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.01	0.03
First Mortgages | Loss severity trends - First mortgage | Maximum | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.14	0.19
First Mortgages | Loss severity trends - First mortgage | Weighted Average | Discounted cash flow | Loans Held For Sale, Residential Real Estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held-for-sale, measurement input	0.08	0.12
Interest-only strips | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 38
Interest-only strips | Available-for-sale Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale		$ 32
Interest-only strips | Constant prepayment rate | Discounted cash flow | Available-for-sale Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input		0.12
Interest-only strips | Constant prepayment rate | Minimum | Discounted cash flow | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.11
Interest-only strips | Constant prepayment rate | Maximum | Discounted cash flow | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.12
Interest-only strips | Constant prepayment rate | Weighted Average | Discounted cash flow | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.11
Interest-only strips | Constant prepayment rate | Weighted Average | Discounted cash flow | Available-for-sale Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input		0.12
Interest-only strips | Bond equivalent yield | Minimum | Discounted cash flow | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.11
Interest-only strips | Bond equivalent yield | Minimum | Discounted cash flow | Available-for-sale Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input		0.15
Interest-only strips | Bond equivalent yield | Maximum | Discounted cash flow | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.14
Interest-only strips | Bond equivalent yield | Maximum | Discounted cash flow | Available-for-sale Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input		0.17
Interest-only strips | Bond equivalent yield | Weighted Average | Discounted cash flow | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input	0.11
Interest-only strips | Bond equivalent yield | Weighted Average | Discounted cash flow | Available-for-sale Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale, measurement input		0.15