Fair Value Measurement of Assets and Liabilities - Fair Value Measurements of Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	$ 25.1	$ 1.4
Contingent payments related to acquisitions	42.1	48.2
Total Liabilities	70.1	183.2
Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	25.1	1.4
Total Liabilities	28.0	135.0
Fair Value Measurements at Reporting Date Using: Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent payments related to acquisitions	42.1	48.2
Total Liabilities	42.1	48.2
Foreign Exchange Forward Contracts [Member] | Derivatives Designated as Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, current and long-term	14.3	0.5
Derivatives, current and long-term	12.7	48.5
Foreign Exchange Forward Contracts [Member] | Derivatives Not Designated as Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, current and long-term		0.9
Derivatives, current and long-term		3.2
Foreign Exchange Forward Contracts [Member] | Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Derivatives Designated as Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, current and long-term	14.3	0.5
Derivatives, current and long-term	12.7	48.5
Foreign Exchange Forward Contracts [Member] | Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Derivatives Not Designated as Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, current and long-term		0.9
Derivatives, current and long-term		3.2
Cross-currency Interest Rate Swaps [Member] | Derivatives Designated as Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, current and long-term	10.8
Derivatives, current and long-term	15.3	83.3
Cross-currency Interest Rate Swaps [Member] | Fair Value Measurements at Reporting Date Using: Significant Other Observable Inputs (Level 2) [Member] | Derivatives Designated as Hedges [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, current and long-term	10.8
Derivatives, current and long-term	$ 15.3	$ 83.3