Loans Held for Investment - Student Loan Portfolio Average Balances (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2024 |
Sep. 30, 2023 |
Sep. 30, 2024 |
Sep. 30, 2023 |
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Average Balance | $ 20,497,173 | $ 21,213,165 | $ 20,805,777 | $ 21,615,968 |
| Private Education Loans | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Average Balance | $ 20,497,173 | $ 20,649,663 | $ 20,805,777 | $ 21,032,541 |
| Weighted Average Interest Rate | 10.79% | 10.96% | 10.90% | 10.80% |
| FFELP Loans(1) | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Average Balance | $ 0 | $ 563,502 | $ 0 | $ 583,427 |
| Weighted Average Interest Rate | 0.00% | 7.35% | 0.00% | 7.10% |