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Loans - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Accrued interest receivable | $ 1,100 |  | $ 1,200
TDRs | 2,000 |  | 2,100
Commitments to lend on loans modified in TDRs | 178 |  | 173
Federal Home Loan banks |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans Pledged as Collateral | 12,800 |  | 14,100
Line of Credit Facility, Remaining Borrowing Capacity | 18,400 |  | 19,600
Federal Reserve Discount Window |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans Pledged as Collateral | 28,800 |  | 25,500
Line of Credit Facility, Remaining Borrowing Capacity | 22,900 |  | 20,000
Credit Card and Consumer Banking | Performing |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
TDRs | 1,300 |  | 1,300
Commercial Banking | Performing |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
TDRs | 354 |  | $ 442
Domestic credit card: | Credit Card |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Revolving loans converted to term during period | $ 97 | $ 160 |

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