Annual report [Section 13 and 15(d), not S-K Item 405]

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

v3.25.0.1
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
Dec. 31, 2024
Dec. 31, 2023
Estimated Fair Value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option $ 18,669,962 $ 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 519,948 574,271
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 155 957
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 3,454 4,246
Estimated Fair Value | HMBS related obligations    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 18,444,370 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 8,950,445 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 3,623 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 9,268,866 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 19,537 133,990
Unpaid Principal Balance    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 17,652,495 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 503,727 558,577
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 222 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 4,331 9,247
Unpaid Principal Balance | HMBS related obligations    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 17,652,495 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 9,351,132 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 12,787 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 9,186,447 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 $ 32,250 $ 136,622