MSR Related Financing Liabilities, at Fair Value - Schedule of Assets, Liabilities Related to MSR Transfer Agreements (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Servicing Liabilities at Fair Value [Line Items]
Other financing liabilities, at fair value	$ 613.1	$ 842.0
Assets serviced	199,800.0	191,100.0
Carrying Value
Servicing Liabilities at Fair Value [Line Items]
Other financing liabilities, at fair value	613.1	842.0
Fair Value
Servicing Liabilities at Fair Value [Line Items]
Other financing liabilities, at fair value	613.1	842.0
Financing Liability Mortgage Servicing Rights Pledged [Member]
Servicing Liabilities at Fair Value [Line Items]
Other financing liabilities, at fair value	346.8	573.2
Transferred MSR, Subject To Pledged Liability
Servicing Liabilities at Fair Value [Line Items]
Assets serviced	22,600.0	38,600.0
Rithm Capital Corp \| Financing Liability Mortgage Servicing Rights Pledged [Member] \| Carrying Value
Servicing Liabilities at Fair Value [Line Items]
Other financing liabilities, at fair value	38.5
Rithm Capital Corp \| Financing Liability Mortgage Servicing Rights Pledged [Member] \| Fair Value
Servicing Liabilities at Fair Value [Line Items]
Other financing liabilities, at fair value		110.6
Rithm Capital Corp \| Transferred MSR, Subject To Pledged Liability
Servicing Liabilities at Fair Value [Line Items]
Assets serviced	3,300.0
Rithm Capital Corp \| Transferred MSR, Subject To Pledged Liability \| Carrying Value
Servicing Liabilities at Fair Value [Line Items]
Assets serviced	$ 3,300.0
Rithm Capital Corp \| Transferred MSR, Subject To Pledged Liability \| Fair Value
Servicing Liabilities at Fair Value [Line Items]
Assets serviced		$ 8,300.0