Investment in Securities (Summary of Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Securities, Available-for-sale [Line Items]
Interest Income	$ 101,520	$ 87,174
Agency RMBS
Securities, Available-for-sale [Line Items]
Coupon Interest	9,067	9,349
Net Amortization	(1,998)	(2,228)
Interest Income	7,069	7,121
Non-Agency RMBS and CMBS
Securities, Available-for-sale [Line Items]
Coupon Interest	8,687	6,431
Net Amortization	(849)	161
Interest Income	7,838	6,592
CLOs
Securities, Available-for-sale [Line Items]
Coupon Interest	1,885	953
Net Amortization	(376)	187
Interest Income	1,509	1,140
Other Securities
Securities, Available-for-sale [Line Items]
Coupon Interest	7,124	5,843
Net Amortization	(2,658)	(1,374)
Interest Income	4,466	4,469
Securities Investment [Member]
Securities, Available-for-sale [Line Items]
Coupon Interest	26,763	22,576
Net Amortization	(5,881)	(3,254)
Interest Income	$ 20,882	$ 19,322