Loans Held For Sale - Summary of Net Gain on Loan Purchase, Origination and Sale Activities on Residential Mortgage Loans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Receivables [Abstract]
Mortgage servicing rights capitalized upon sale of loans	$ 922.8	$ 864.5
Net proceeds from sale of loans	(820.0)	(785.6)
Provision for and change in estimate of liability for losses under representations and warranties, net	5.0	5.2
Change in fair value	(17.0)	15.0
Unrealized gain (loss) on derivatives	61.4	(18.4)
Realized (loss) gain on derivatives	(3.3)	55.4
Total change in fair value of derivatives	58.1	37.0
Net gain on residential mortgage loans HFS	148.9	136.1
Loan acquisition and origination fees	57.4	57.4
Net gain on loan origination and sale activities	$ 206.3	$ 193.5	$ 104.0