Note 5 - Derivative and Other Hedging Instruments - Schedule of Derivative Instruments Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Gains (losses) on derivative and other hedging instruments	$ 46,308	$ (74,659)
Short [Member] | US Treasury Securities [Member]
Gains (losses) on derivative and other hedging instruments	(603)	0
Interest Rate Futures Contracts [Member] | Short [Member]
Gains (losses) on derivative and other hedging instruments	4,437	(14,942)
Interest Rate Swap [Member]
Gains (losses) on derivative and other hedging instruments	41,002	(62,843)
TBA Contracts [Member] | Short [Member]
Gains (losses) on derivative and other hedging instruments	195	3,026
TBA Contracts [Member] | Long [Member]
Gains (losses) on derivative and other hedging instruments	$ 1,277	$ 100