Investment in Securities (Unrealized Loss Positions Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 158,495	$ 720,249
Unrealized Losses, Less than 12 Months	(3,275)	(60,343)
Fair Value, Greater than 12 Months	451,992	365,355
Unrealized Losses, Greater than 12 Months	(48,765)	(66,704)
Fair Value, Total	610,487	1,085,604
Unrealized Loss, Total	(52,040)	(127,047)
Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	125,112	577,047
Unrealized Losses, Less than 12 Months	(730)	(51,817)
Fair Value, Greater than 12 Months	426,834	326,223
Unrealized Losses, Greater than 12 Months	(45,854)	(57,564)
Fair Value, Total	551,946	903,270
Unrealized Loss, Total	(46,584)	(109,381)
CLOs
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	7,152	6,035
Unrealized Losses, Less than 12 Months	(69)	(466)
Fair Value, Greater than 12 Months	5	12,212
Unrealized Losses, Greater than 12 Months	0	(3,488)
Fair Value, Total	7,157	18,247
Unrealized Loss, Total	(69)	(3,954)
Other Securities
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	15,930	90,523
Unrealized Losses, Less than 12 Months	(2,276)	(2,855)
Fair Value, Greater than 12 Months	10,958	726
Unrealized Losses, Greater than 12 Months	(2,029)	(693)
Fair Value, Total	26,888	91,249
Unrealized Loss, Total	(4,305)	(3,548)
Non-Agency RMBS and CMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	10,301	46,644
Unrealized Losses, Less than 12 Months	(200)	(5,205)
Fair Value, Greater than 12 Months	14,195	26,194
Unrealized Losses, Greater than 12 Months	(882)	(4,959)
Fair Value, Total	24,496	72,838
Unrealized Loss, Total	$ (1,082)	$ (10,164)