Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	$ (26.3)	$ (69.6)
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	3.3
Foreign currency contract liabilities	(26.3)	(69.6)
Deferred compensation plan	24.2	22.6
Total recurring fair value measurements	1.2	(47.0)
Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	0.0
Foreign currency contract liabilities	0.0	0.0
Deferred compensation plan	12.9	12.2
Total recurring fair value measurements	12.9	12.2
Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	3.3
Foreign currency contract liabilities	(26.3)	(69.6)
Deferred compensation plan	0.0	0.0
Total recurring fair value measurements	(23.0)	(69.6)
Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	0.0
Foreign currency contract liabilities	0.0	0.0
Deferred compensation plan	0.0	0.0
Total recurring fair value measurements	0.0	0.0
NAV | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	0.0
Foreign currency contract liabilities	0.0	0.0
Deferred compensation plan	11.3	10.4
Total recurring fair value measurements	$ 11.3	$ 10.4