Note 5 - Derivative and Other Hedging Instruments - Schedule of Derivative Instruments Gain (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
(Losses) gains on derivative instruments	$ (122,669)	$ 133,554	$ 45,237
Short [Member] | US Treasury Securities [Member]
(Losses) gains on derivative instruments	(98)	0	0
Treasury Note Future [Member] | Short [Member]
(Losses) gains on derivative instruments	(30,282)	26,638	32,650
Interest Rate Swap [Member]
(Losses) gains on derivative instruments	(81,687)	101,151	19,657
Payer Swaptions [Member] | Short [Member]
(Losses) gains on derivative instruments	0	0	4,113
Payer Swaptions [Member] | Long [Member]
(Losses) gains on derivative instruments	0	(72)	(8,734)
Interest Rate Cap [Member]
(Losses) gains on derivative instruments	0	0	(219)
Dual Digital Option [Member]
(Losses) gains on derivative instruments	0	(500)	0
Interest Rate Floor [Member] | Short [Member]
(Losses) gains on derivative instruments	0	0	(525)
Interest Rate Floor [Member] | Long [Member]
(Losses) gains on derivative instruments	0	0	1,785
TBA Contracts [Member] | Short [Member]
(Losses) gains on derivative instruments	(12,289)	6,567	1,370
TBA Contracts [Member] | Long [Member]
(Losses) gains on derivative instruments	$ 1,687	$ (230)	$ (4,860)