Note 5 - Derivative and Other Hedging Instruments - Schedule of To Be Announced Securities (Details) - Short [Member] - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Five Percent TBA Securities [Member]
Notional Amount	[1]	$ 100,000
Cost	[2]	97,617
Market value	[3]	97,386
Net carrying value		(231)
Notional Amount	[1]	(100,000)
Three Percent TBA Securities [Member]
Notional Amount	[1]	350,000	$ 500,000
Cost	[2]	(297,154)	(440,644)
Market value	[3]	(290,116)	(440,274)
Net carrying value		7,038	370
Notional Amount	[1]	(350,000)	(500,000)
Six Percent TBA Securities [Member]
Notional Amount	[1]	100,000
Cost	[2]	(99,872)
Market value	[3]	(98,766)
Net carrying value		1,106
Notional Amount	[1]	(100,000)
Six and a Half Percent TBA Securities [Member]
Notional Amount	[1]	152,500
Cost	[2]	(154,382)
Market value	[3]	(153,310)
Net carrying value		1,072
Notional Amount	[1]	(152,500)
TBA Contracts [Member]
Notional Amount	[1]	502,500	675,000
Cost	[2]	(453,791)	(582,912)
Market value	[3]	(444,806)	(583,419)
Net carrying value		8,985	(507)
Notional Amount	[1]	$ (502,500)	(675,000)
Two Percent TBA Contract [Member]
Notional Amount	[1]		175,000
Cost	[2]		(142,268)
Market value	[3]		(143,145)
Net carrying value	[4]		(877)
Notional Amount	[1]		$ (175,000)

[1] Notional amount represents the par value (or principal balance) of the underlying Agency RMBS.

[2] Cost basis represents the forward price to be paid (received) for the underlying Agency RMBS.

[3] Market value represents the current market value of the TBA securities (or of the underlying Agency RMBS) as of period-end.

[4] Net carrying value represents the difference between the market value and the cost basis of the TBA securities as of period-end and is reported in derivative assets (liabilities), at fair value in our balance sheets