Reverse Mortgage Loan Portfolio - Schedule of Composition and Remaining UPBs of Reverse Mortgage Loan Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for investment, subject to HMBS related obligations	$ 18,056,054	$ 17,983,144
Total loans held for investment, subject to nonrecourse debt	10,284,554	9,567,732
Loans held for investment	421,049	790,342
Loans held for sale	79,664	34,515
Reverse mortgage loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for investment, subject to HMBS related obligations	18,056,054	17,983,144
Total loans held for investment, subject to nonrecourse debt	10,284,554	9,567,732
Loans held for investment	415,093	783,323
Loans held for sale	77,460	32,761
Total owned loan portfolio	28,833,161	28,366,960
Total serviced loan portfolio	29,396,094	29,008,074
Non-agency reverse mortgages
Fair Value, Option, Quantitative Disclosures [Line Items]
Total loans held for investment, subject to nonrecourse debt	9,555,033	8,887,778
Loans held for investment	225,348	614,515
Performing HECM buyouts
Fair Value, Option, Quantitative Disclosures [Line Items]
Total loans held for investment, subject to nonrecourse debt	266,648	251,051
Nonperforming HECM buyouts
Fair Value, Option, Quantitative Disclosures [Line Items]
Total loans held for investment, subject to nonrecourse debt	462,873	428,903
HECM loans not securitized
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for investment	133,471	103,825
Unpoolable HECM loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for investment	$ 56,274	64,983
Maximum claim amount ("MCA") (in percent)	98.00%
Loans reclassified as government guaranteed receivable
Fair Value, Option, Quantitative Disclosures [Line Items]
Total serviced loan portfolio	$ 50,817	50,922
Loans serviced for others
Fair Value, Option, Quantitative Disclosures [Line Items]
Total serviced loan portfolio	512,116	590,192
Pledged As Collateral, Financing Lines Of Credit
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for sale	$ 422,300	$ 753,200

Fair Value, Option, Loans Held-For-Investment And Loans Held-For-Sale, Unpaid Principal Balance

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