Mortgage-Backed Securities - Gains and Losses from Sales of Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Net realized gain (loss)	$ (3,750)	$ (5,264)
Non-Agency RMBS
Debt Securities, Available-for-sale [Line Items]
Proceeds from sales:	0	0
Gross realized gains:	0	0
Gross realized losses:	0	0
Agency RMBS
Debt Securities, Available-for-sale [Line Items]
Proceeds from sales:	0	0
Gross realized gains:	0	0
Gross realized losses:	0	0
Agency CMBS
Debt Securities, Available-for-sale [Line Items]
Proceeds from sales:	34,672	167,675
Gross realized gains:	0	0
Gross realized losses:	$ (3,750)	$ (5,264)