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Commitments - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Jun. 30, 2025 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024
Other Commitments [Line Items] |  |  |  |
Threshold of outstanding principal balance on maximum claim amount (as a percent) |  | 98.00% |  |
Floating Rate Reverse Mortgage Loans |  |  |  |
Other Commitments [Line Items] |  |  |  |
Additional borrowing capacity to borrowers |  | $ 3,000.0 |  | $ 3,100.0
Funded amount in connection with reverse mortgage loans |  | 236.6 |  |
Forward Mortgage Loan Interest Rate Lock Commitments |  |  |  |
Other Commitments [Line Items] |  |  |  |
Short-term commitments to lend |  | 2,400.0 |  |
Reverse loans IRLCs |  |  |  |
Other Commitments [Line Items] |  |  |  |
Short-term commitments to lend |  | $ 33.9 |  |
Rithm Capital Corp |  |  |  |
Other Commitments [Line Items] |  |  |  |
Mortgage Loans, Right To Transfer, Percentage |  | 15.00% |  |
Unpaid Principal Balance, Transfers Out | $ 5,700.0 |  |  |
Customer Concentration Risk | Servicing And Subservicing Fees Benchmark | Rithm Capital Corp |  |  |  |
Other Commitments [Line Items] |  |  |  |
Concentration risk (percent) |  | 13.00% | 16.00% |
Concentration Risk, Amount |  | $ 60.2 | $ 73.5 |
Customer Concentration Risk | Unpaid Principal Balance | Rithm Capital Corp |  |  |  |
Other Commitments [Line Items] |  |  |  |
Concentration risk (percent) |  | 10.00% |  |
Concentration Risk, Amount |  | $ 33,000.0 |  |
Customer Concentration Risk | Loan Count | Rithm Capital Corp |  |  |  |
Other Commitments [Line Items] |  |  |  |
Concentration risk (percent) |  | 20.00% |  |
Customer Concentration Risk | Delinquent Loans | Rithm Capital Corp |  |  |  |
Other Commitments [Line Items] |  |  |  |
Concentration risk (percent) |  | 55.00% |  |
Customer Concentration Risk | Pledged MSR Liability Expense Benchmark | Rithm Capital Corp |  |  |  |
Other Commitments [Line Items] |  |  |  |
Concentration Risk, Amount |  | $ 27.6 | $ 27.6 |

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