Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Summary of Fair Value and Unpaid Principal Balance ("UPB") of Financial Assets and Liabilities With Elected Fair Value Option (Details)

v3.24.3
Fair Value - Summary of Fair Value and Unpaid Principal Balance ("UPB") of Financial Assets and Liabilities With Elected Fair Value Option (Details) - USD ($)
$ in Thousands
Sep. 30, 2024
Dec. 31, 2023
Estimated Fair Value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option $ 18,521,337 $ 17,548,763
Estimated Fair Value | Loans held for investment | Reverse mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 702,858 574,271
Estimated Fair Value | Loans held for investment | Commercial mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 498 957
Estimated Fair Value | Loans held for sale | Loans held for sale - residential mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 1,151 4,246
Estimated Fair Value | HMBS related obligations    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 18,292,043 17,353,720
Estimated Fair Value | Nonrecourse debt in consolidated VIE trusts and reverse loan financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 8,528,429 7,876,932
Estimated Fair Value | Nonrecourse commercial loan financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 8,690 27,268
Estimated Fair Value | Reverse mortgage loans | Loans held for investment, subject to nonrecourse debt, at fair value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 9,063,459 8,138,403
Estimated Fair Value | Commercial mortgage loans | Loans held for investment, subject to nonrecourse debt, at fair value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 33,910 133,990
Unpaid Principal Balance    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 17,493,824 16,875,437
Unpaid Principal Balance | Loans held for investment | Reverse mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 648,344 558,577
Unpaid Principal Balance | Loans held for investment | Commercial mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 702 1,044
Unpaid Principal Balance | Loans held for sale | Loans held for sale - residential mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 1,487 9,247
Unpaid Principal Balance | HMBS related obligations    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 17,493,824 16,875,437
Unpaid Principal Balance | Nonrecourse debt in consolidated VIE trusts and reverse loan financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 8,847,008 8,429,135
Unpaid Principal Balance | Nonrecourse commercial loan financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 14,075 26,661
Unpaid Principal Balance | Reverse mortgage loans | Loans held for investment, subject to nonrecourse debt, at fair value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 8,783,102 8,257,750
Unpaid Principal Balance | Commercial mortgage loans | Loans held for investment, subject to nonrecourse debt, at fair value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option $ 43,653 $ 136,622