Accrued Expenses and Other Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued incentive compensation	$ 268.2	$ 234.5
Accrued compensation and benefits	64.1	64.6
Lease liability	45.4	45.0
Deferred revenue	78.2	79.9
Reserve for policy cancellations	52.6	39.2
Accrued interest	33.2	33.2
Accrued rent and vendor expenses	20.9	14.9
Other	45.6	30.2
Total	$ 608.2	$ 541.5