Other Current Assets and Accrued Expenses and Other Current Liabilities - Summary of Other Current Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid agent incentives	$ 22.2	$ 48.4
Other	32.3	28.1
Other current assets	$ 54.5	$ 76.5