Investment in Securities (Unrealized Loss Positions Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 977,598	$ 1,094,937
Unrealized Losses, Less than 12 Months	(117,719)	(16,006)
Fair Value, Greater than 12 Months	291,949	44,888
Unrealized Losses, Greater than 12 Months	(59,923)	(6,414)
Fair Value, Total	1,269,547	1,139,825
Unrealized Loss, Total	(177,642)	(22,420)
Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	873,628	1,083,017
Unrealized Losses, Less than 12 Months	(108,405)	(15,190)
Fair Value, Greater than 12 Months	245,402	39,124
Unrealized Losses, Greater than 12 Months	(46,133)	(1,815)
Fair Value, Total	1,119,030	1,122,141
Unrealized Loss, Total	(154,538)	(17,005)
Non-Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	64,863	11,296
Unrealized Losses, Less than 12 Months	(5,565)	(802)
Fair Value, Greater than 12 Months	30,650	4,462
Unrealized Losses, Greater than 12 Months	(7,862)	(1,850)
Fair Value, Total	95,513	15,758
Unrealized Loss, Total	(13,427)	(2,652)
CLOs
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	5,985	624
Unrealized Losses, Less than 12 Months	(504)	(14)
Fair Value, Greater than 12 Months	15,332	1,302
Unrealized Losses, Greater than 12 Months	(5,081)	(2,749)
Fair Value, Total	21,317	1,926
Unrealized Loss, Total	(5,585)	$ (2,763)
Other Securities
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	33,122
Unrealized Losses, Less than 12 Months	(3,245)
Fair Value, Greater than 12 Months	565
Unrealized Losses, Greater than 12 Months	(847)
Fair Value, Total	33,687
Unrealized Loss, Total	$ (4,092)