Reverse Mortgages - Schedule of Reverse Mortgage Revenue, Net (Details) - USD ($) $ in Millions	1 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2025	Nov. 30, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on new originations			$ 21.1	$ 22.8	$ 20.5
Net interest income (servicing fee)			31.6	26.2	23.6
Other change in fair value of securitized loans and HMBS-related borrowings, net			1.2	(9.7)	(0.1)
Change in fair value included in earnings, net			53.9	39.4	44.0
Gain (loss) on derivatives, net			(40.9)	(82.5)	(8.2)
Loan fees and other			3.2	3.1	2.8
Gain on reverse loans and HMBS-related borrowings, net	$ 1.6	$ 57.2	58.8	42.5	46.7
Interest rate futures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain (loss) on derivatives, net			$ 1.6	$ 0.0	$ 0.0