Investment in Securities (Summary of Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Securities, Available-for-sale [Line Items]
Interest Income	$ 88,092	$ 62,722	$ 175,266	$ 113,796
Agency RMBS
Securities, Available-for-sale [Line Items]
Coupon Interest	9,503	12,941	18,852	27,276
Net Amortization	(1,687)	(1,892)	(3,916)	(8,029)
Interest Income	7,816	11,049	14,936	19,247
Non-Agency RMBS and CMBS
Securities, Available-for-sale [Line Items]
Coupon Interest	7,387	4,772	13,818	8,858
Net Amortization	(202)	103	(41)	131
Interest Income	7,185	4,875	13,777	8,989
CLOs
Securities, Available-for-sale [Line Items]
Coupon Interest	880	1,887	1,833	3,616
Net Amortization	(206)	(620)	(18)	(1,205)
Interest Income	674	1,267	1,815	2,411
Other Securities
Securities, Available-for-sale [Line Items]
Coupon Interest	5,640	4,587	11,483	10,144
Net Amortization	(1,021)	(1,036)	(2,395)	(2,149)
Interest Income	4,619	3,551	9,088	7,995
Securities Investment [Member]
Securities, Available-for-sale [Line Items]
Coupon Interest	23,410	24,187	45,986	49,894
Net Amortization	(3,116)	(3,445)	(6,370)	(11,252)
Interest Income	$ 20,294	$ 20,742	$ 39,616	$ 38,642