Reverse Mortgages - Fair Value Gains (Losses) on Reverse Loans and HMBS-Related Borrowings (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
Receivables [Abstract]
Change in fair value	$ (31.8)	$ (657.2)	$ 689.0	$ 621.2	$ 519.0
Change in fair value			$ (635.0)	$ (581.8)	$ (475.0)
Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Gain on reverse loans and HMBS-related borrowings, net	Gain on reverse loans and HMBS-related borrowings, net	Gain on reverse loans and HMBS-related borrowings, net
Change in fair value included in earnings, net			$ 53.9	$ 39.4	$ 44.0