Note 2 - Mortgage-backed Securities, at Fair Value - Schedule of RMBS Portfolio (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Dec. 31, 2025 |
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|---|---|---|---|---|---|---|---|---|---|---|
| Mortgage-backed securities, par value | $ 11,396,946 | $ 10,345,029 | ||||||||
| Mortgage-backed securities, cost | [1] | 11,617,232 | 10,574,339 | |||||||
| Pledged assets, Mortgage-backed securities | 11,540,164 | 10,628,658 | ||||||||
| Fixed Rate Mortgages [Member] | ||||||||||
| Mortgage-backed securities, par value | 11,396,946 | 10,345,029 | ||||||||
| Mortgage-backed securities, cost | [1] | 11,602,269 | 10,558,236 | |||||||
| Pledged assets, Mortgage-backed securities | 11,528,198 | 10,615,570 | ||||||||
| Financial Instrument, Other [Member] | ||||||||||
| Mortgage-backed securities, par value | [2],[3],[4] | 0 | ||||||||
| Mortgage-backed securities, cost | [1],[2],[3],[4] | 14,963 | 16,103 | |||||||
| Pledged assets, Mortgage-backed securities | [2],[3],[4] | $ 11,966 | $ 13,088 | |||||||
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