Derivative Instruments and Hedging Activities - Fair Value of Derivative Instruments on Gross Basis (Detail) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 113.6	$ 76.7
Derivative Liabilities	12.6	16.1
Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	46.7	37.9
Foreign Exchange Forward Contracts [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	20.1	20.9
Foreign Exchange Forward Contracts [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	9.5	9.9
Foreign Exchange Forward Contracts [Member] | Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	3.1	3.7
Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets		2.8
Cross-currency Interest Rate Swaps [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 46.8	15.1
Cross-currency Interest Rate Swaps [Member] | Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities		$ 2.5