v3.26.1
Fair Value Measurements - Changes in the Fair Value of Securities Classified as Level 3 (Details) - USD ($)
 6 Months Ended 12 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets Measured on Recurring Basis [Roll Forward]    
Transfers into Level 3 $ 0 $ 0
Transfers out of Level 3 0 0
Securitized debt | Variable Interest Entities, Primary Beneficiary | Level 3    
Gains (losses) included in net income    
Total unrealized gains (losses) for the period 0 0
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]    
Beginning balance Level 3 6,721,302,000 6,984,495,000
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Issuance of debt 378,755,000 1,011,244,000
Principal payments (507,814,000) (1,161,220,000)
Sales and settlements (1,190,049,000) (382,110,000)
Net (accretion) amortization 10,321,000 21,837,000
Realized (gains) losses on sales and settlements 41,605,000 (2,142,000)
Net unrealized (gains) losses included in income (45,843,000) 249,197,000
Total unrealized (gains) losses for the period 0 0
Securitized Debt, Ending balance, Level 3 5,408,277,000 6,721,302,000
Non-Agency RMBS | Level 3    
Fair Value, Assets Measured on Recurring Basis [Roll Forward]    
Beginning balance Level 3 817,287,000 1,064,169,000
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Capital contribution (distribution) 0 0
Purchases of assets 502,000 1,289,000
Principal payments (50,805,000) (92,195,000)
Sales and settlements (13,491,000) (165,029,000)
Servicer advances, net 0 0
Net (accretion) amortization 13,618,000 27,792,000
Amortization of MSR loan pool 0 0
Gains (losses) included in net income    
(Increase) decrease in provision for credit losses (10,016,000) (15,705,000)
Realized gains (losses) on sales and settlements (5,021,000) (16,103,000)
Interest income from investment in MSR financing receivables 0 0
Net unrealized (gains) losses included in income (6,633,000) 26,221,000
Total unrealized gains (losses) for the period (17,820,000) (13,152,000)
Ending balance Level 3 727,621,000 817,287,000
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]    
Total unrealized (gains) losses for the period 17,820,000 13,152,000
Interests in MSR financing receivables | Level 3    
Fair Value, Assets Measured on Recurring Basis [Roll Forward]    
Beginning balance Level 3 37,294,000  
Transfers into Level 3 0  
Transfers out of Level 3 0  
Capital contribution (distribution) (7,544,000)  
Purchases of assets 0  
Principal payments 0  
Sales and settlements 0  
Servicer advances, net (2,020,000)  
Net (accretion) amortization 0  
Amortization of MSR loan pool (4,640,000)  
Gains (losses) included in net income    
(Increase) decrease in provision for credit losses 0  
Realized gains (losses) on sales and settlements 0  
Interest income from investment in MSR financing receivables 7,789,000  
Net unrealized (gains) losses included in income 4,592,000  
Total unrealized gains (losses) for the period 0  
Ending balance Level 3 35,471,000 37,294,000
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]    
Total unrealized (gains) losses for the period 0  
Interests in MSR financing receivables | Variable Interest Entities, Primary Beneficiary | Level 3    
Fair Value, Assets Measured on Recurring Basis [Roll Forward]    
Beginning balance Level 3 37,295,000 0
Transfers into Level 3   0
Transfers out of Level 3   0
Capital contribution (distribution)   38,221,000
Purchases of assets   0
Principal payments   0
Sales and settlements   0
Servicer advances, net   2,145,000
Net (accretion) amortization   0
Amortization of MSR loan pool   (3,930,000)
Gains (losses) included in net income    
(Increase) decrease in provision for credit losses   0
Realized gains (losses) on sales and settlements   0
Interest income from investment in MSR financing receivables   4,451,000
Net unrealized (gains) losses included in income   (3,592,000)
Total unrealized gains (losses) for the period   0
Ending balance Level 3   37,295,000
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]    
Total unrealized (gains) losses for the period   0
Loans held for investment | Variable Interest Entities, Primary Beneficiary | Level 3    
Fair Value, Assets Measured on Recurring Basis [Roll Forward]    
Beginning balance Level 3 9,728,264,000 10,858,845,000
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Capital contribution (distribution) 0 0
Purchases of assets 468,012,000 0
Principal payments (541,565,000) (1,198,667,000)
Sales and settlements (1,662,592,000) (174,471,000)
Servicer advances, net 0 0
Net (accretion) amortization (958,000) (5,058,000)
Amortization of MSR loan pool 0 0
Gains (losses) included in net income    
(Increase) decrease in provision for credit losses 0 0
Realized gains (losses) on sales and settlements (35,407,000) (18,254,000)
Interest income from investment in MSR financing receivables 0 0
Net unrealized (gains) losses included in income (100,643,000) 265,868,000
Total unrealized gains (losses) for the period 0 0
Ending balance Level 3 7,855,111,000 9,728,264,000
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]    
Total unrealized (gains) losses for the period 0 0
Derivative | Variable Interest Entities, Primary Beneficiary | Level 3    
Fair Value, Assets Measured on Recurring Basis [Roll Forward]    
Beginning balance Level 3 3,855,000 0
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Capital contribution (distribution) 0 0
Purchases of assets 0 5,073,000
Principal payments 0 0
Sales and settlements 0 0
Servicer advances, net 0 0
Net (accretion) amortization 0 0
Amortization of MSR loan pool
Gains (losses) included in net income    
(Increase) decrease in provision for credit losses 0 0
Realized gains (losses) on sales and settlements 0 0
Interest income from investment in MSR financing receivables 0 0
Net unrealized (gains) losses included in income 200,000 (1,218,000)
Total unrealized gains (losses) for the period 0 0
Ending balance Level 3 4,055,000 3,855,000
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]    
Total unrealized (gains) losses for the period $ 0 $ 0