Mortgage-Backed Securities - Significant Credit Quality Indicators (Details) $ in Thousands	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,054,694	$ 1,078,739
Non-Agency RMBS - Senior
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	485,808	505,633
Non-Agency RMBS - Senior | Credit Quality Indicator, Updated Quarterly
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 105,000	$ 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	0.097	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	0.022	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	0.335	0.353
Non-Agency RMBS - Subordinated
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 389,434	$ 300,411
Non-Agency RMBS - Subordinated | Credit Quality Indicator, Updated Quarterly
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 67,750	$ 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	0.075	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	0.437	0.389