Investment in Securities (Unrealized Loss Positions Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 720,249	$ 1,094,937
Unrealized Losses, Less than 12 Months	(60,343)	(16,006)
Fair Value, Greater than 12 Months	365,355	44,888
Unrealized Losses, Greater than 12 Months	(66,704)	(6,414)
Fair Value, Total	1,085,604	1,139,825
Unrealized Loss, Total	(127,047)	(22,420)
Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	577,047	1,083,017
Unrealized Losses, Less than 12 Months	(51,817)	(15,190)
Fair Value, Greater than 12 Months	326,223	39,124
Unrealized Losses, Greater than 12 Months	(57,564)	(1,815)
Fair Value, Total	903,270	1,122,141
Unrealized Loss, Total	(109,381)	(17,005)
Non-Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	46,644	11,296
Unrealized Losses, Less than 12 Months	(5,205)	(802)
Fair Value, Greater than 12 Months	26,194	4,462
Unrealized Losses, Greater than 12 Months	(4,959)	(1,850)
Fair Value, Total	72,838	15,758
Unrealized Loss, Total	(10,164)	(2,652)
CLOs
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	6,035	624
Unrealized Losses, Less than 12 Months	(466)	(14)
Fair Value, Greater than 12 Months	12,212	1,302
Unrealized Losses, Greater than 12 Months	(3,488)	(2,749)
Fair Value, Total	18,247	1,926
Unrealized Loss, Total	(3,954)	$ (2,763)
Other Securities
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	90,523
Unrealized Losses, Less than 12 Months	(2,855)
Fair Value, Greater than 12 Months	726
Unrealized Losses, Greater than 12 Months	(693)
Fair Value, Total	91,249
Unrealized Loss, Total	$ (3,548)