Note 7 - Offsetting Assets and Liabilities - Offsetting Liabilities (Details) - Liability [Member] - USD ($) $ in Thousands |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Gross amount, recognized | $ 10,362,897 | $ 10,117,312 |
| Gross Amount, offset | 0 | 0 |
| Net Amount | 10,362,897 | 10,117,312 |
| Gross Amount, not recognized | (10,231,673) | (10,064,295) |
| Gross amount, not offset | (130,044) | (53,017) |
| Net amount, after deduction | 1,180 | 0 |
| Repurchase Agreements [Member] | ||
| Gross amount, recognized | 10,361,717 | 10,115,466 |
| Gross Amount, offset | 0 | 0 |
| Net Amount | 10,361,717 | 10,115,466 |
| Gross Amount, not recognized | (10,231,673) | (10,064,295) |
| Gross amount, not offset | (130,044) | (51,171) |
| Net amount, after deduction | 0 | 0 |
| TBA Contracts [Member] | ||
| Gross amount, recognized | 1,180 | 1,846 |
| Gross Amount, offset | 0 | 0 |
| Net Amount | 1,180 | 1,846 |
| Gross Amount, not recognized | 0 | 0 |
| Gross amount, not offset | 0 | (1,846) |
| Net amount, after deduction | $ 1,180 | $ 0 |