Derivative Instruments and Hedging Activities - Gross Unrealized Losses from Derivative Instruments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized cash flow hedge gains (losses), Before Tax	$ 38.1	$ (35.9)	$ 67.7	$ (99.0)
Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized cash flow hedge gains (losses), Before Tax	38.1	(35.9)	67.7	(99.0)
Amount of Gain / (Loss) Reclassified from AOCI	(5.0)	(5.2)	(26.9)	11.6
Foreign Exchange Forward Contracts [Member] | Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized cash flow hedge gains (losses), Before Tax	38.8	(35.6)	68.3	(98.7)
Foreign Exchange Forward Contracts [Member] | Cash Flow Hedges [Member] | Cost of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain / (Loss) Reclassified from AOCI	(4.9)	(5.1)	(26.5)	12.0
Interest Rate Swaps [Member] | Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized cash flow hedge gains (losses), Before Tax	(0.7)	(0.3)	(0.6)	(0.3)
Forward Starting Interest Rate Swaps [Member] | Cash Flow Hedges [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain / (Loss) Reclassified from AOCI	$ (0.1)	$ (0.1)	$ (0.4)	$ (0.4)