Mortgage-Backed Securities - Significant Credit Quality Indicators (Details) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,062,822	$ 1,078,739
Non-Agency RMBS - Senior
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	497,496	505,633
Non-Agency RMBS - Senior | Credit Quality Indicator, Updated Quarterly
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 98,495	$ 98,394
Non-Agency RMBS - Senior | Credit Quality Indicator, Updated Quarterly | Weighted Average Borrowing Rates | Prepay Rate
Debt Securities, Available-for-sale [Line Items]
Significant Inputs	0.071	0.062
Non-Agency RMBS - Senior | Credit Quality Indicator, Updated Quarterly | Weighted Average Borrowing Rates | CDR
Debt Securities, Available-for-sale [Line Items]
Significant Inputs	0.023	0.023
Non-Agency RMBS - Senior | Credit Quality Indicator, Updated Quarterly | Weighted Average Borrowing Rates | Loss Severity
Debt Securities, Available-for-sale [Line Items]
Significant Inputs	0.373	0.353
Non-Agency RMBS - Subordinated
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 332,120	$ 300,411
Non-Agency RMBS - Subordinated | Credit Quality Indicator, Updated Quarterly
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 72,053	$ 75,005
Non-Agency RMBS - Subordinated | Credit Quality Indicator, Updated Quarterly | Weighted Average Borrowing Rates | Prepay Rate
Debt Securities, Available-for-sale [Line Items]
Significant Inputs	0.065	0.062
Non-Agency RMBS - Subordinated | Credit Quality Indicator, Updated Quarterly | Weighted Average Borrowing Rates | CDR
Debt Securities, Available-for-sale [Line Items]
Significant Inputs	0.003	0.007
Non-Agency RMBS - Subordinated | Credit Quality Indicator, Updated Quarterly | Weighted Average Borrowing Rates | Loss Severity
Debt Securities, Available-for-sale [Line Items]
Significant Inputs	0.447	0.389