Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill	$ 4,295.3	$ 4,217.4
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	2.5	5.5
Foreign Currency Contracts, Liability, Fair Value Disclosure	(13.5)	(5.4)
Deferred compensation plan	45.4	47.9
Derivative Assets (Liabilities), at Fair Value, Net	34.4	48.0
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 assets	0.0	0.0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0.0	0.0
Deferred compensation plan	39.9	41.6
Derivative Assets (Liabilities), at Fair Value, Net	39.9	41.6
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 assets	2.5	5.5
Foreign Currency Contracts, Liability, Fair Value Disclosure	(13.5)	(5.4)
Deferred compensation plan	5.5	6.3
Derivative Assets (Liabilities), at Fair Value, Net	(5.5)	6.4
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 assets	0.0	0.0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0.0	0.0
Deferred compensation plan	0.0	0.0
Derivative Assets (Liabilities), at Fair Value, Net	$ 0.0	$ 0.0