Segment Reporting Assets and Liabilities by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total Assets	$ 14,085,886	$ 5,177,419
Liabilities	12,865,000	3,853,863
Total Equity	1,220,886	1,323,556	$ 921,572	$ 868,699
Investment Portfolio Segment
Segment Reporting Information [Line Items]
Total Assets	5,635,657	4,989,777
Liabilities	4,499,669	3,726,394
Total Equity	1,135,988	1,263,383
Longbridge Segment
Segment Reporting Information [Line Items]
Total Assets	8,227,509
Liabilities	8,092,313
Total Equity	135,196
Corporate and Other
Segment Reporting Information [Line Items]
Total Assets	222,720	187,642
Liabilities	273,018	127,469
Total Equity	$ (50,298)	$ 60,173