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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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