Borrowings - Summary of Exposure Related To Unconsolidated VIEs (Details) - USD ($) $ in Thousands |
Sep. 30, 2026 |
Jun. 30, 2026 |
Dec. 31, 2025 |
Sep. 30, 2025 |
Jun. 30, 2025 |
Dec. 31, 2024 |
|---|---|---|---|---|---|---|
| Debt Instrument [Line Items] | ||||||
| Estimated Fair Value | $ 2,847,109 | $ 1,758,070 | ||||
| Total Exposure | 93,704 | $ 66,015 | 77,132 | $ 97,877 | $ 52,541 | $ 84,568 |
| Variable Interest Entity, Not Primary Beneficiary | Private Education Loan term securitizations | ||||||
| Debt Instrument [Line Items] | ||||||
| Estimated Fair Value | 708,289 | 622,184 | ||||
| Equity Interests | 41,308 | 49,250 | ||||
| Total Exposure | $ 749,597 | $ 671,434 |
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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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