Mortgage-Backed Securities - Gross Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	$ 195,364	$ 203,285
Gross Unrealized Gain Included in Cumulative Earnings	29,775	22,354
Total Gross Unrealized Gain	225,139	225,639
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(11,718)	(17,617)
Gross Unrealized Loss Included in Cumulative Earnings	(103,412)	(121,911)
Total Gross Unrealized Loss	(115,130)	(139,528)
Non-Agency RMBS - Senior
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	184,226	192,528
Total Gross Unrealized Loss	(4,545)	(6,981)
Non-Agency RMBS - Subordinated
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	21,697	16,548
Total Gross Unrealized Loss	(22,954)	(36,548)
Non-Agency RMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	14,914	14,394
Total Gross Unrealized Loss	(77,442)	(81,490)
Agency RMBS - CMO
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	2,031
Total Gross Unrealized Loss	0
Agency RMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	1,263	862
Total Gross Unrealized Loss	(4,155)	(5,077)
Agency CMBS - Project loans
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	0	0
Total Gross Unrealized Loss	(5,208)	(8,641)
Agency CMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Total Gross Unrealized Gain	1,008	1,307
Total Gross Unrealized Loss	(826)	(791)
Residential Mortgage-Backed Securities | Non-Agency RMBS - Senior
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	184,226	192,528
Gross Unrealized Gain Included in Cumulative Earnings	0	0
Total Gross Unrealized Gain	184,226	192,528
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(3,659)	(5,396)
Gross Unrealized Loss Included in Cumulative Earnings	(887)	(1,585)
Total Gross Unrealized Loss	(4,545)	(6,981)
Residential Mortgage-Backed Securities | Non-Agency RMBS - Subordinated
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	11,138	10,757
Gross Unrealized Gain Included in Cumulative Earnings	10,559	5,791
Total Gross Unrealized Gain	21,697	16,548
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	(8,059)	(12,198)
Gross Unrealized Loss Included in Cumulative Earnings	(14,895)	(24,350)
Total Gross Unrealized Loss	(22,954)	(36,548)
Residential Mortgage-Backed Securities | Non-Agency RMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	14,914	14,394
Total Gross Unrealized Gain	14,914	14,394
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(77,442)	(81,490)
Total Gross Unrealized Loss	(77,442)	(81,490)
Residential Mortgage-Backed Securities | Agency RMBS - CMO
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0
Gross Unrealized Gain Included in Cumulative Earnings	2,031
Total Gross Unrealized Gain	2,031
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0
Gross Unrealized Loss Included in Cumulative Earnings	0
Total Gross Unrealized Loss	0
Residential Mortgage-Backed Securities | Agency RMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	1,263	862
Total Gross Unrealized Gain	1,263	862
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(4,155)	(5,077)
Total Gross Unrealized Loss	(4,155)	(5,077)
Commercial Mortgage Backed Securities | Agency CMBS - Project loans
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	0	0
Total Gross Unrealized Gain	0	0
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	(23)
Gross Unrealized Loss Included in Cumulative Earnings	(5,208)	(8,618)
Total Gross Unrealized Loss	(5,208)	(8,641)
Commercial Mortgage Backed Securities | Agency CMBS - Interest-only
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gain Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Gain Included in Cumulative Earnings	1,008	1,307
Total Gross Unrealized Gain	1,008	1,307
Gross Unrealized Loss Included in Accumulated Other Comprehensive Income	0	0
Gross Unrealized Loss Included in Cumulative Earnings	(826)	(791)
Total Gross Unrealized Loss	$ (826)	$ (791)