Investment in Securities (Unrealized Loss Positions Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 387,534	$ 158,495
Unrealized Losses, Less than 12 Months	(10,598)	(3,275)
Fair Value, Greater than 12 Months	350,628	451,992
Unrealized Losses, Greater than 12 Months	(50,568)	(48,765)
Fair Value, Total	738,162	610,487
Unrealized Loss, Total	(61,166)	(52,040)
Agency RMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	180,991	125,112
Unrealized Losses, Less than 12 Months	(3,896)	(730)
Fair Value, Greater than 12 Months	299,073	426,834
Unrealized Losses, Greater than 12 Months	(39,004)	(45,854)
Fair Value, Total	480,064	551,946
Unrealized Loss, Total	(42,900)	(46,584)
Non-Agency RMBS and CMBS
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	159	10,301
Unrealized Losses, Less than 12 Months	(1)	(200)
Fair Value, Greater than 12 Months	47,168	14,195
Unrealized Losses, Greater than 12 Months	(9,009)	(882)
Fair Value, Total	47,327	24,496
Unrealized Loss, Total	(9,010)	(1,082)
CLOs
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	9,274	7,152
Unrealized Losses, Less than 12 Months	(179)	(69)
Fair Value, Greater than 12 Months	3,560	5
Unrealized Losses, Greater than 12 Months	(876)	0
Fair Value, Total	12,834	7,157
Unrealized Loss, Total	(1,055)	(69)
Other Securities
Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	197,110	15,930
Unrealized Losses, Less than 12 Months	(6,522)	(2,276)
Fair Value, Greater than 12 Months	827	10,958
Unrealized Losses, Greater than 12 Months	(1,679)	(2,029)
Fair Value, Total	197,937	26,888
Unrealized Loss, Total	$ (8,201)	$ (4,305)