v3.26.3
Fair Value of Financial Instruments - Fair Value Methodology (Details) - Residential whole loans
$ in Thousands
Sep. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Residential whole loans, fair value $ 7,726,266 $ 7,717,007
UPB 9,075,870 8,989,910
Marked to Market Approach    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Residential whole loans, fair value 46,300 138,700
UPB 70,600 170,800
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Residential whole loans, fair value 7,681,528 7,665,985
Level 3 | Discounted Cash Flow and Liquidation Model    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Residential whole loans, fair value 7,635,224 7,527,250
Level 3 | Discounted cash flow    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Residential whole loans, fair value $ 7,283,401 $ 7,196,955
Level 3 | Discounted cash flow | Discount rate | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.074 0.065
Level 3 | Discounted cash flow | Discount rate | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.060 0.055
Level 3 | Discounted cash flow | Discount rate | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.115 0.200
Level 3 | Discounted cash flow | Prepayment rate | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.144 0.171
Level 3 | Discounted cash flow | Prepayment rate | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0 0
Level 3 | Discounted cash flow | Prepayment rate | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.474 0.505
Level 3 | Discounted cash flow | Default rate | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.016 0.016
Level 3 | Discounted cash flow | Default rate | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0 0
Level 3 | Discounted cash flow | Default rate | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.653 0.682
Level 3 | Discounted cash flow | Loss severity | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.068 0.114
Level 3 | Discounted cash flow | Loss severity | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0 0
Level 3 | Discounted cash flow | Loss severity | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 1.000 1.000
Level 3 | Liquidation model    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Residential whole loans, fair value $ 351,823 $ 330,295
Level 3 | Liquidation model | Discount rate | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.090 0.091
Level 3 | Liquidation model | Discount rate | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.085 0.080
Level 3 | Liquidation model | Discount rate | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.150 0.200
Level 3 | Liquidation model | Annual change in home prices | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.015 0.019
Level 3 | Liquidation model | Annual change in home prices | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input (0.023) (0.009)
Level 3 | Liquidation model | Annual change in home prices | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.077 0.087
Level 3 | Liquidation model | Liquidation timeline (in years) | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 1.8 1.7
Level 3 | Liquidation model | Liquidation timeline (in years) | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 0.7 0.1
Level 3 | Liquidation model | Liquidation timeline (in years) | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 4.5 4.5
Level 3 | Liquidation model | Current value of underlying properties | Weighted Average    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 734 748
Level 3 | Liquidation model | Current value of underlying properties | Minimum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 19 19
Level 3 | Liquidation model | Current value of underlying properties | Maximum    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement input 8,350 11,400