Acquisitions - Summary of Changes in Contingent Consideration Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes In Contingent Consideration Measured At Fair Value On A Recurring Basis [Roll Forward]
Opening balance	$ 26.9	$ 17.6	$ 20.9	$ 14.0
Acquisitions and measurement period adjustments	(0.3)	4.0	7.1	12.8
Payments	(0.4)	(3.3)	(2.7)	(9.1)
Changes in fair value included in net loss	0.4	0.5	1.3	1.1
Closing balance	$ 26.6	$ 18.8	$ 26.6	$ 18.8