Segment Reporting Assets and Liabilities by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total Assets	$ 15,132,600	$ 15,315,930
Liabilities	13,579,444	13,780,318
Total Equity	1,553,156	1,535,612	$ 1,374,763	$ 1,220,886
Investment Portfolio Segment
Segment Reporting Information [Line Items]
Total Assets	5,620,097	5,978,988
Liabilities	4,097,762	4,555,212
Total Equity	1,522,335	1,423,776
Longbridge Segment
Segment Reporting Information [Line Items]
Total Assets	9,338,455	9,092,840
Liabilities	9,115,860	8,872,153
Total Equity	222,595	220,687
Corporate and Other
Segment Reporting Information [Line Items]
Total Assets	174,048	244,102
Liabilities	365,822	352,953
Total Equity	$ (191,774)	$ (108,851)