Mortgage Servicing - Summary of Activity Related to Fair Value Servicing Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 2,466.3	$ 2,272.2	$ 2,665.2
Servicing Asset at Fair Value, Disposals	(140.7)	(211.0)	(0.1)
Servicing Assets At Fair Value Additions Recognized From Mortgage Sales	385.7	247.6	183.0
Purchase of MSRs	365.3	239.6	109.9
Servicing transfers and adjustments	12.0	87.1	454.3
Servicing assets at fair value, net additions recognized	598.4	189.1	(161.3)
Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions	$ 15.3	$ 232.3	$ 6.4
ServicingAssetAtFairValueOtherChangeInFairValueStatementOfIncomeOrComprehensiveIncomeExtensibleEnumerationNotDisclosedFlag	Realization of cash flows (3)	Realization of cash flows (3)	Realization of cash flows (3)
Servicing Asset at Fair Value, Other Changes in Fair Value	$ (254.6)	$ (227.4)	$ (238.1)
Servicing Asset at Fair Value, Period Increase (Decrease)	(239.3)	5.0	(231.7)
Ending balance	$ 2,825.3	$ 2,466.3	2,272.2
Financing Receivable, Percent Past Due	5.70%	6.50%
Derivative, Gain (Loss) on Derivative, Net	$ 40.9	$ 82.5	8.2
MSR valuation adjustments, net	(169.8)	(96.2)	(232.2)
ESS Financing Liability
Servicing Asset at Fair Value, Amount [Roll Forward]
Changes in fair value	14.1	59.0	62.4
Runoff and Settlements	71.4	70.8	94.2
Total Fair value changes in Servicing liability at fair value	$ 57.3	$ 11.8	31.8
Financial Asset, 30 to 59 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	2.90%	3.10%
Financial Asset, 60 to 89 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	1.00%	1.10%
Financial Asset, Equal to or Greater than 90 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	1.90%	2.30%
Fair Value Non Agency Mortgage Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 212.2
Ending balance	$ 207.4	$ 212.2
Financing Receivable, Percent Past Due	17.50%	18.70%
Fair Value Non Agency Mortgage Servicing Rights | Rithm
Servicing Asset at Fair Value, Amount [Roll Forward]
Servicing Asset At Fair Value, Amount, Derecognition			(421.7)
Fair Value Non Agency Mortgage Servicing Rights | Financial Asset, 30 to 59 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	8.50%	8.40%
Fair Value Non Agency Mortgage Servicing Rights | Financial Asset, 60 to 89 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	2.90%	3.40%
Fair Value Non Agency Mortgage Servicing Rights | Financial Asset, Equal to or Greater than 90 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	6.10%	6.90%
Fair Value GSE Mortgage Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 1,902.5
Ending balance	$ 2,089.2	$ 1,902.5
Financing Receivable, Percent Past Due	1.70%	1.80%
Fair Value GSE Mortgage Servicing Rights | MAV Asset Vehicle LLC
Servicing Asset at Fair Value, Amount [Roll Forward]
Servicing transfers and adjustments			(32.5)
Servicing Asset At Fair Value, Amount, Derecognition	$ 0.0	$ 85.7
Fair Value GSE Mortgage Servicing Rights | Financial Asset, 30 to 59 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	1.00%	1.00%
Fair Value GSE Mortgage Servicing Rights | Financial Asset, 60 to 89 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	0.30%	0.20%
Fair Value GSE Mortgage Servicing Rights | Financial Asset, Equal to or Greater than 90 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	0.40%	0.50%
MAV Transferred Mortgage Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 330.6
Ending balance	312.5	$ 330.6
Transferred MSR, Subject To Pledged Liability
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	596.7
Ending balance	$ 581.0	$ 596.7
Amount	38,600.0	40,500.0
Transferred MSR, Subject To Pledged Liability | Rithm
Servicing Asset at Fair Value, Amount [Roll Forward]
Ending balance	$ 110.6
Amount	8,300.0
MSR
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 2,466.3
Servicing Asset at Fair Value, Period Increase (Decrease)	239.3	$ (5.0)	$ 230.8
Ending balance	$ 2,825.3	$ 2,466.3
Amount	191,100.0	170,300.0
Fair Value of GNMA Mortgage Servicing Rights
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 351.6
Ending balance	$ 528.6	$ 351.6
Financing Receivable, Percent Past Due	9.90%	11.80%
Fair Value of GNMA Mortgage Servicing Rights | Financial Asset, 30 to 59 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	4.90%	5.40%
Fair Value of GNMA Mortgage Servicing Rights | Financial Asset, 60 to 89 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	1.70%	1.80%
Fair Value of GNMA Mortgage Servicing Rights | Financial Asset, Equal to or Greater than 90 Days Past Due
Servicing Asset at Fair Value, Amount [Roll Forward]
Financing Receivable, Percent Past Due	3.40%	4.50%
Financing Liability Excess Servicing Spread
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 377.9
Ending balance	$ 373.5	$ 377.9