Annual report pursuant to Section 13 and 15(d)

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

v3.24.0.1
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, 2023
Dec. 31, 2022
Estimated Fair Value    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option $ 17,548,763 $ 11,114,100
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 574,271 771,724
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 957 136,274
Estimated Fair Value | Loans held for sale | Commercial mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option   161,861
Estimated Fair Value | Loans held for sale | Residential mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 4,246 12,123
Estimated Fair Value | Reverse mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option   9,356
Estimated Fair Value | HMBS related obligations    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 17,353,720 10,996,755
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 7,876,932 7,175,857
Estimated Fair Value | Nonrecourse commercial loan financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 27,268 106,758
Estimated Fair Value | Nonrecourse MSR financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option   60,562
Estimated Fair Value | Reverse mortgage loans | Loans held for investment, subject to nonrecourse debt    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 8,138,403 7,065,477
Estimated Fair Value | Commercial mortgage loans | Loans held for investment, subject to nonrecourse debt    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 133,990 389,161
Unpaid Principal Balance    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 16,875,437 10,719,000
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 558,577 724,800
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 1,044 143,373
Unpaid Principal Balance | Loans held for sale | Commercial mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option   173,112
Unpaid Principal Balance | Loans held for sale | Residential mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 9,247 15,529
Unpaid Principal Balance | Reverse mortgage loans    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option   9,356
Unpaid Principal Balance | HMBS related obligations    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 16,875,437 10,719,000
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 8,429,135 7,819,992
Unpaid Principal Balance | Nonrecourse commercial loan financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option 26,661 105,291
Unpaid Principal Balance | Nonrecourse MSR financing liability    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Liabilities at fair value under the fair value option   60,562
Unpaid Principal Balance | Reverse mortgage loans | Loans held for investment, subject to nonrecourse debt    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option 8,257,750 7,240,125
Unpaid Principal Balance | Commercial mortgage loans | Loans held for investment, subject to nonrecourse debt    
Fair Value, Option, Quantitative Disclosures [Line Items]    
Assets at fair value under the fair value option $ 136,622 $ 405,970