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Fair Value Measurements - Narrative (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Jun. 30, 2026 | Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Other equity investments | $ 503,000,000 | $ 467,000,000
Impairment loss | 0 |
Total principal investments |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Net asset value | 7,000,000 |
Unfunded commitments | 50,000,000 |
Carrying Amount | Education Lending | Discontinued operations |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Loans, net of allowance | 182,000,000 | 205,000,000
Estimate of Fair Value Measurement | Education Lending | Discontinued operations |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Loans, net of allowance | 138,000,000 | 155,000,000
Estimate of Fair Value Measurement | Nonrecurring |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Liabilities measured at fair value on non recurring basis | $ 0 | $ 0

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