Note 4 - Derivative and Other Hedging Instruments - Schedule of Derivative Instruments in Balance Sheet (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents, Current, Total	$ 31,568	$ 65,299
Other liabilities	(25,119)	(35,505)
Interest Rate Swap [Member]
Notional Amount	1,400,000	1,355,000
Payer Swaptions [Member] | Long [Member]
Notional Amount	1,370,000	1,658,500
Net Estimated Fair Value	33,398	21,493
Interest Rate Cap [Member]
Notional Amount	200,000
Cost	$ 1,450
Strike Swap Rate	0.09%
Curve Spread (Year)	2 years 9 months 29 days
Net Estimated Fair Value	$ 1,119
TBA Contracts [Member] | Short [Member]
Notional Amount	675,000	575,000
Cost	(582,912)	(595,630)
Net Estimated Fair Value	507	304
Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative assets, at fair value	40,172	50,786
Derivative liabilities, at fair value	7,161	7,589
Restricted Cash and Cash Equivalents, Current, Total	5,206	829
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Swap [Member]
Derivative assets, at fair value	4,983	29,293
Derivative liabilities, at fair value	0	2,862
Other liabilities	0	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Payer Swaptions [Member] | Long [Member]
Derivative assets, at fair value	33,398	21,493
Not Designated as Hedging Instrument, Economic Hedge [Member] | Payer Swaptions [Member] | Short [Member]
Derivative liabilities, at fair value	5,982	4,423
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Cap [Member]
Derivative assets, at fair value	1,119	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | TBA Contracts [Member]
Derivative assets, at fair value	672	0
Derivative liabilities, at fair value	1,179	304
Restricted Cash and Cash Equivalents, Current, Total	1,734	0
Other liabilities	(532)	(856)
Not Designated as Hedging Instrument, Economic Hedge [Member] | Eurodollar Future Margin [Member]
Restricted Cash and Cash Equivalents, Current, Total	16,493	8,035
Not Designated as Hedging Instrument, Economic Hedge [Member] | Interest Rate Swaption [Member]
Other liabilities	$ (12,489)	$ (6,350)