Investment in Securities (Unrealized Loss Positions Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 596,862	$ 720,249
Unrealized Losses, Less than 12 Months	(11,350)	(60,343)
Fair Value, Greater than 12 Months	495,937	365,355
Unrealized Losses, Greater than 12 Months	(72,379)	(66,704)
Fair Value, Total	1,092,799	1,085,604
Unrealized Loss, Total	(83,729)	(127,047)
Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	459,363	577,047
Unrealized Losses, Less than 12 Months	(8,795)	(51,817)
Fair Value, Greater than 12 Months	423,269	326,223
Unrealized Losses, Greater than 12 Months	(57,692)	(57,564)
Fair Value, Total	882,632	903,270
Unrealized Loss, Total	(66,487)	(109,381)
Non-Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	601	46,644
Unrealized Losses, Less than 12 Months	(10)	(5,205)
Fair Value, Greater than 12 Months	46,920	26,194
Unrealized Losses, Greater than 12 Months	(10,369)	(4,959)
Fair Value, Total	47,521	72,838
Unrealized Loss, Total	(10,379)	(10,164)
CLOs
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	1,268	6,035
Unrealized Losses, Less than 12 Months	(4)	(466)
Fair Value, Greater than 12 Months	13,624	12,212
Unrealized Losses, Greater than 12 Months	(2,560)	(3,488)
Fair Value, Total	14,892	18,247
Unrealized Loss, Total	(2,564)	(3,954)
Other Securities
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	135,630	90,523
Unrealized Losses, Less than 12 Months	(2,541)	(2,855)
Fair Value, Greater than 12 Months	12,124	726
Unrealized Losses, Greater than 12 Months	(1,758)	(693)
Fair Value, Total	147,754	91,249
Unrealized Loss, Total	$ (4,299)	$ (3,548)