Note 2 - Mortgage-backed Securities, at Fair Value (Details Textual) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Notional Balance, Interest Only Securities Portfolio, Amount | $ 68.5 | $ 72.9 |
| Notional Balance, Inverse Interest Only Securities Portfolio, Amount | $ 14.1 | $ 17.7 |