Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	$ (32.4)	$ (69.6)
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	(32.4)	(69.6)
Deferred compensation plan	22.5	22.6
Total recurring fair value measurements	(9.9)	(47.0)
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	0.0	0.0
Deferred compensation plan	12.0	12.2
Total recurring fair value measurements	12.0	12.2
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	(32.4)	(69.6)
Deferred compensation plan	0.0	0.0
Total recurring fair value measurements	(32.4)	(69.6)
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	0.0	0.0
Deferred compensation plan	0.0	0.0
Total recurring fair value measurements	0.0	0.0
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	0.0	0.0
Deferred compensation plan	10.5	10.4
Total recurring fair value measurements	$ 10.5	$ 10.4