Fair Value Measurement of Assets and Liabilities - Schedule of Fair Value Liabilities Measured on Recurring Basis (Detail) - Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member] - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 299.2	$ 180.7
New contingent consideration related to acquisitions	188.7	35.0
Change in estimates	25.2	(62.8)
Settlements	$ (78.4)	$ (52.8)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Acquisition Integration Divestiture And Related Expenses	Acquisition Integration Divestiture And Related Expenses
Foreign currency impact	$ 0.2	$ 2.1
Ending balance	$ 434.9	$ 102.2