Note 5 - Derivative and Other Hedging Instruments - Schedule of Derivative Instruments in Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Restricted Cash and Cash Equivalents, Current	$ 15,968	$ 28,396
Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative assets, at fair value	29,319	6,420
Derivative liabilities, at fair value	844	12,694
Total margin balances on derivative contracts	4,783	28,396
Not Designated as Hedging Instrument, Economic Hedge [Member] | Long [Member]
Derivative assets, at fair value	0	72
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Swap [Member]
Derivative assets, at fair value	29,214	6,348
Not Designated as Hedging Instrument, Economic Hedge [Member] | Dual Digital Option [Member]
Derivative assets, at fair value	105	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | TBA Contracts [Member]
Derivative assets, at fair value	844	12,694
Derivative liabilities, at fair value	2,282	23,720
Not Designated as Hedging Instrument, Economic Hedge [Member] | Eurodollar Future Margin [Member]
Restricted Cash and Cash Equivalents, Current	2,098	4,096
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Swaption [Member]
Restricted Cash and Cash Equivalents, Current	$ 403	$ 580