Mortgage-Backed Securities - Unrealized Loss Positions (Details) $ in Thousands	Sep. 30, 2024 USD ($) security	Dec. 31, 2023 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 94,656	$ 136,549
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ (1,065)	$ (10,352)
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	27	52
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 304,522	$ 306,074
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (114,065)	$ (129,176)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	201	186
Total, Estimated Fair Value	$ 399,178	$ 442,623
Total, Unrealized Losses	$ (115,130)	$ (139,528)
Total, Number of Positions | security	228	238
Residential Mortgage-Backed Securities | Non-Agency RMBS - Senior
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 32,959	$ 51,476
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ 0	$ (281)
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	10	13
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 37,268	$ 42,859
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (4,545)	$ (6,700)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	6	6
Total, Estimated Fair Value	$ 70,228	$ 94,335
Total, Unrealized Losses	$ (4,545)	$ (6,981)
Total, Number of Positions | security	16	19
Residential Mortgage-Backed Securities | Non-Agency RMBS - Subordinated
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 53,963	$ 19,382
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ (184)	$ (1,467)
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	5	5
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 174,548	$ 181,822
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (22,770)	$ (35,081)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	30	33
Total, Estimated Fair Value	$ 228,511	$ 201,204
Total, Unrealized Losses	$ (22,954)	$ (36,548)
Total, Number of Positions | security	35	38
Residential Mortgage-Backed Securities | Non-Agency RMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 318	$ 19,263
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ (25)	$ (4,035)
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	5	27
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 51,342	$ 36,731
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (77,417)	$ (77,455)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	124	105
Total, Estimated Fair Value	$ 51,660	$ 55,994
Total, Unrealized Losses	$ (77,442)	$ (81,490)
Total, Number of Positions | security	129	132
Residential Mortgage-Backed Securities | Agency RMBS - CMO
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 0
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ 0
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	0
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 0
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ 0
Unrealized Loss Position for 12 Months or More, Number of Positions | security	0
Total, Estimated Fair Value	$ 0
Total, Unrealized Losses	$ 0
Total, Number of Positions | security	0
Residential Mortgage-Backed Securities | Agency RMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 0	$ 0
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ 0	$ 0
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	0	0
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 8,533	$ 9,151
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (4,155)	$ (5,077)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	7	8
Total, Estimated Fair Value	$ 8,532	$ 9,151
Total, Unrealized Losses	$ (4,155)	$ (5,077)
Total, Number of Positions | security	7	8
Commercial Mortgage Backed Securities | Agency CMBS - Project loans
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 5,582	$ 43,827
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ (633)	$ (4,040)
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	5	5
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 30,720	$ 35,353
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (4,575)	$ (4,601)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	31	32
Total, Estimated Fair Value	$ 36,302	$ 79,180
Total, Unrealized Losses	$ (5,208)	$ (8,641)
Total, Number of Positions | security	36	37
Commercial Mortgage Backed Securities | Agency CMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Unrealized Loss Position for Less than 12 Months, Estimated Fair Value	$ 1,834	$ 2,601
Unrealized Loss Position for Less than 12 Months, Unrealized Losses	$ (223)	$ (529)
Unrealized Loss Position for Less than 12 Months, Number of Positions | security	2	2
Unrealized Loss Position for 12 Months or More, Estimated Fair Value	$ 2,111	$ 158
Unrealized Loss Position for 12 Months or More, Unrealized Losses	$ (603)	$ (262)
Unrealized Loss Position for 12 Months or More, Number of Positions | security	3	2
Total, Estimated Fair Value	$ 3,945	$ 2,759
Total, Unrealized Losses	$ (826)	$ (791)
Total, Number of Positions | security	5	4