Advances - Schedule of Activity in Advances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Advances [Roll Forward]
Advances, beginning balance	$ 584.6	$ 686.1	$ 725.1
New advances	962.4	927.5	779.8
Transfer to Other assets	2.1	(8.3)	(14.7)
Sales of advances	(1.6)	(14.2)	(6.3)
Acquisition of advances in connection with the purchase of MSRs	5.1	0.8	42.2
Transfer to Loans held for sale (incl. capitalization upon Ginnie Mae modifications)	(17.5)	(9.3)	(6.4)
Collections of advances and other	(1,043.0)	(1,014.5)	(863.0)
Advances, ending balance	487.9	584.6	686.1
Advances, net	$ 483.4	$ 577.2	$ 678.8