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v3.21.2

Allowance for Credit Losses - Additional Information (Details) - USD ($) | 9 Months Ended |  |  |
--- | --- | --- | --- | ---
Sep. 30, 2021 | Dec. 31, 2020 | Sep. 30, 2020 | Jul. 01, 2006
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Reduction to provision for credit losses | $ 427,000,000 |  |  |
Moody's Analytics Base and S4 downturn scenarios, applicable weight in determining allowance for credit losses | 50.00% |  |  |
Interest rate offered to borrowers facing financial difficulty | 4.00% |  |  |
Interest rate offered to borrowers facing financial difficulty, period | 2 years |  |  |
Percentage of loans in full and interest repayment status that are subject to interest rate reductions | 9.20% |  | 8.80% |
Percentage of loans granted forbearance (as a percentage) | 47.00% | 47.00% |  |
Criteria for loans to be considered as nonperforming (greater than) | 90 days |  |  |
Tier 1 of government guarantee (at least) | 97.00% |  |  | 97.00%
TDR payment default period (more than) | 60 days |  |  |
Percentage of FFELP loans insured and guaranteed (at least) | 97.00% |  |  |
Period of loans past due that have accrued interest (greater than) | 90 days |  |  |
Monthly payment that is smaller than the interest accrued on the loan in that month | $ 25 |  |  |
Maximum |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Interest rate offered to borrowers facing financial difficulty | 4.00% |  |  |

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