v3.26.3
Fair Value of Financial Instruments - Schedule of Carrying Value and Estimated Fair Value of the Company's Financial Assets and Liabilities (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Jun. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Dec. 31, 2024
Financial Assets:            
Cash and cash equivalents $ 262,360   $ 210,333 $ 185,285    
Residential loans, carrying value 4,788,939   4,358,175      
Equity investments, carrying value 17,926   24,711      
Equity investment, estimated fair value 17,926   24,711      
Derivative assets 11,393   722      
Mortgage servicing rights, fair value 18,970 $ 19,093 20,893 $ 21,896 $ 19,449 $ 21,003
Financial Liabilities:            
Repurchase agreements and warehouse facilities 7,460,119   6,753,417      
Collateralized debt obligations:            
Carrying Value 3,791,951   3,511,802      
Subordinated debentures, carrying value 45,000   45,000      
Derivative liabilities, carrying value 14,039   0      
Senior unsecured notes:            
Senior unsecured notes, carrying value 434,607   360,437      
Senior unsecured notes, estimated fair value 434,607   260,852      
Mortgages payable on real estate, carrying value 758,776          
VIE, Primary Beneficiary | Mortgages            
Senior unsecured notes:            
Mortgages payable on real estate, carrying value 274,923   332,131      
Residential loan securitizations at amortized cost, net            
Collateralized debt obligations:            
Carrying Value 328,681   363,645      
Residential loan securitizations at amortized cost, net | VIE, Primary Beneficiary            
Collateralized debt obligations:            
Carrying Value 328,681   363,645      
Consolidated SLST            
Collateralized debt obligations:            
Carrying Value 3,463,270   3,148,157      
Consolidated SLST | VIE, Primary Beneficiary            
Collateralized debt obligations:            
Carrying Value 3,463,270   3,148,157      
Senior unsecured notes at amortized cost, net            
Senior unsecured notes:            
Senior unsecured notes, carrying value     99,585      
Senior unsecured notes at fair value            
Senior unsecured notes:            
Senior unsecured notes, carrying value 434,607   260,852      
Level 1            
Financial Assets:            
Cash and cash equivalents 262,360   210,333      
Cash and cash equivalents, estimated fair value 262,360   210,333      
Equity investment, estimated fair value 0   0      
Mortgage servicing rights, fair value 0   0      
Senior unsecured notes:            
Senior unsecured notes, estimated fair value 0   0      
Level 2            
Financial Assets:            
Investment securities available for sale: 7,343,161   6,904,781      
Equity investment, estimated fair value 0   0      
Derivative assets 11,114   31      
Fair Value 11,114   31      
Mortgage servicing rights, fair value $ 0   $ 0      
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other assets   Other assets      
Collateralized debt obligations:            
Derivative liabilities, carrying value $ 14,039   $ 0      
Derivative liabilities, estimated fair value 14,039   0      
Senior unsecured notes:            
Senior unsecured notes, estimated fair value $ 434,607   $ 260,852      
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Other liabilities   Other liabilities      
Level 2 | Repurchase agreements            
Financial Liabilities:            
Repurchase agreements and warehouse facilities $ 7,460,119   $ 6,753,417      
Level 2 | Residential loan securitizations at amortized cost, net            
Collateralized debt obligations:            
Residential loan securitizations at fair value, carrying value 2,438,853   2,075,962      
Residential loan securitizations at fair value 2,438,853   2,075,962      
Level 2 | Non-Agency RMBS re-securitization | VIE, Primary Beneficiary            
Collateralized debt obligations:            
Carrying Value 108,719   65,276      
Collateralized debt obligations, fair value 108,719   65,276      
Level 2 | Senior unsecured notes at amortized cost, net            
Senior unsecured notes:            
Senior unsecured notes, carrying value 0   99,585      
Senior unsecured notes, estimated fair value 0   99,465      
Level 2 | Senior unsecured notes at fair value            
Senior unsecured notes:            
Senior unsecured notes, carrying value 434,607   260,852      
Senior unsecured notes, estimated fair value 434,607   260,852      
Level 3            
Financial Assets:            
Equity investments, carrying value 17,926   24,711      
Equity investment, estimated fair value 17,926   24,711      
Mortgage servicing rights, fair value 18,970   20,893      
Collateralized debt obligations:            
Subordinated debentures, carrying value 45,000   45,000      
Subordinated debentures, estimated fair value 42,031   40,526      
Senior unsecured notes:            
Senior unsecured notes, estimated fair value 0   0      
Level 3 | Mortgages            
Financial Assets:            
Mortgage servicing rights, carrying value 18,970   20,893      
Mortgage servicing rights, fair value 18,970   20,893      
Senior unsecured notes:            
Mortgages payable on real estate, carrying value 274,923   332,131      
Mortgages payable on real estate, estimated fair value 263,664   325,301      
Level 3 | Residential loan securitizations at amortized cost, net            
Collateralized debt obligations:            
Carrying Value 328,681   363,645      
Collateralized debt obligations, fair value 310,791   349,037      
Level 3 | Consolidated SLST | VIE, Primary Beneficiary            
Collateralized debt obligations:            
Carrying Value 915,698   1,006,919      
Collateralized debt obligations, fair value 915,698   1,006,919      
Level 3 | Total Residential loans            
Financial Assets:            
Residential loans, carrying value 4,788,939   4,358,175      
Residential mortgage loans at fair value 4,788,939   4,358,175      
Level 3 | Residential loans held for sale            
Financial Assets:            
Residential loans, carrying value 150,969   80,707      
Residential mortgage loans at fair value 150,969   80,707      
Level 3 | Multi-family loans            
Financial Assets:            
Multi-family loans, carrying value 36,868   55,476      
Multi-family loans, estimated fair value 36,868   55,476      
Level 3 | IRLCs            
Financial Assets:            
Derivative assets 279   691      
Fair Value $ 279   $ 691