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	Mar. 31, 2022 USD ($) month	Dec. 31, 2021 USD ($) month
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale at fair value	$ 9,242	$ 8,707
Loans held-for-sale	193	258
Derivative liability	430	103
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	18	23
Loans net of unearned income	106	84
OREO, fair value	3	3
Other Assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	$ 30	30
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	0.55
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	0.65
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
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	5,800
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	6,200
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	$ 6,000
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	15
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	35
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	0.24
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	9	12
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	33	36
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	22	25
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	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	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	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	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	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	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	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	$ 33	$ 29
Residential Real Estate | 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		54
Residential Real Estate | 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		66
Residential Real Estate | 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
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	0.03	4
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	12
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	1
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	0.13	14
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	0.07	0.08
Interest- only strips | Trading Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale at fair value	$ 12	$ 38
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	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	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	0.11
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	0.11
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	0.13	0.14
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	0.11
SBAs | 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	$ 1
SBAs | 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	8
SBAs | 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	12
SBAs | 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	0.10
SBAs | Bond equivalent yield | 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	0.09
SBAs | 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		11
SBAs | 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	0.09	0.11