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v3.25.2

Fair Value Measurements - Fair Values of Financial Assets and Liabilities, Including Derivative Financial Instruments (Detail) - USD ($) $ in Millions | Jun. 30, 2025 | Dec. 31, 2024 | Jun. 30, 2024
--- | --- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Total earning assets, Carrying Value | $ 47,360 | $ 48,814 |
Short-term borrowings, Carrying Value | 4,752 | 5,134 |
Long-term borrowings, Carrying Value | 42,345 | 43,184 |
Total | 47,097 | 48,318 |
Total earning assets, Fair Value | 46,689 | 48,379 |
Short-term borrowings, Fair Value | 4,764 | 5,144 |
Long-term borrowings, Fair Value | 41,672 | 42,361 |
Total interest-bearing liabilities, Fair Value | 46,436 | 47,505 |
FFELP Loans [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Loans, Carrying Value | 29,618 | 30,852 |
Loans receivable, Fair Value | 29,261 | 30,766 |
Interest Rate Swaps [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Derivative financial instruments, Carrying Value | 43 | 25 |
Derivative financial instruments, Fair Value | 43 | 25 |
Cross-Currency Interest Rate Swaps [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Derivative financial instruments, Carrying Value | (75) | (244) |
Derivative financial instruments, Fair Value | (75) | (244) |
Private Education Loans [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Loans, Carrying Value | 15,530 | 15,716 | $ 16,238
Loans receivable, Fair Value | 15,216 | 15,367 |
Difference [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Cash and investments | 0 | 0 |
Total earning assets, Fair Value | (671) | (435) |
Short-term borrowings, Fair Value | (12) | (10) |
Long-term borrowings, Fair Value | 673 | 823 |
Total interest-bearing liabilities, Fair Value | 661 | 813 |
Excess of net asset fair value over carrying value | (10) | 378 |
Difference [Member] | FFELP Loans [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Loans receivable, Fair Value | (357) | (86) |
Difference [Member] | Interest Rate Swaps [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Derivative financial instruments, Fair Value | 0 | 0 |
Difference [Member] | Cross-Currency Interest Rate Swaps [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Derivative financial instruments, Fair Value | 0 | 0 |
Difference [Member] | Private Education Loans [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Loans receivable, Fair Value | (314) | (349) |
Carrying Value [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Cash and investments | 2,212 | 2,246 |
Fair Value [Member] |  |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |  |
Cash and investments | $ 2,212 | $ 2,246 |

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