Investments in Securities - Schedule of Investments Classified by Contractual Maturity Date (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Fair Value | ||
| Less than 1 year | $ 0 | $ 0 |
| Greater than or equal to 1 year and less than 3 years | 153,593 | 1,934,537 |
| Greater than or equal to 3 years and less than 5 years | 5,042,391 | 8,305,993 |
| Greater than or equal to 5 years | 15,987,660 | 9,775,219 |
| Totals | 21,183,644 | 20,015,749 |
| Amortized Cost | ||
| Less than 1 year | 0 | 0 |
| Greater than or equal to 1 year and less than 3 years | 151,594 | 1,910,316 |
| Greater than or equal to 3 years and less than 5 years | 5,017,685 | 8,201,320 |
| Greater than or equal to 5 years | 16,097,733 | 9,744,210 |
| Totals | $ 21,267,012 | $ 19,855,846 |