Derivative Instruments and Hedging Activities - Fair Value of Derivative Instruments on Gross Basis (Detail) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 138.2	$ 112.1
Derivative Liabilities	6.6	13.1
Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	38.5	41.8
Foreign Exchange Forward Contracts [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	11.1	9.8
Foreign Exchange Forward Contracts [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	2.9	7.9
Foreign Exchange Forward Contracts [Member] | Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	3.7	5.2
Cross-currency Interest Rate Swaps [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	29.1
Cross-currency Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 59.5	$ 60.5