Note 2 - Mortgage-backed Securities and U.S. Treasury Securities, At Fair Value (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Marketable Securities [Table Text Block]

(in thousands)
	December 31, 2023						December 31, 2022
	Par Value		Cost (1)		Fair Value		Par Value		Cost (1)		Fair Value
Pass-Through RMBS Certificates:
Fixed-rate Mortgages	$	4,051,145	$	4,198,424	$	3,877,082	$	3,848,367	$	4,088,165	$	3,519,906
Total Pass-Through Certificates		4,051,145		4,198,424		3,877,082		3,848,367		4,088,165		3,519,906
Structured RMBS Certificates:
Interest-Only Securities (2)		n/a		19,839		16,572		n/a		22,395		19,669
Inverse Interest-Only Securities (3)		n/a		1,825		358		n/a		2,147		427
Total Structured RMBS Certificates		-		21,664		16,930		-		24,542		20,096
Total	$	4,051,145	$	4,220,088	$	3,894,012	$	3,848,367	$	4,112,707	$	3,540,002

Gain (Loss) on Securities [Table Text Block]

(in thousands)
	2023			2022			2021
Proceeds from sales of RMBS	$	797,633		$	2,759,919		$	2,851,708
Carrying value of RMBS sold		(820,275	)		(2,893,614	)		(2,857,250	)
Net loss on sales of RMBS	$	(22,642	)	$	(133,695	)	$	(5,542	)
Gross gain on sales of RMBS	$	-		$	2,705		$	7,930
Gross loss on sales of RMBS		(22,642	)		(136,400	)		(13,472	)
Net loss on sales of RMBS	$	(22,642	)	$	(133,695	)	$	(5,542	)