Derivatives - Schedule of Pretax Effects of Derivative Financial Instruments Designated or Previously Designated as Effective Hedges (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	$ 2.1	$ 17.0	$ (4.6)	$ 8.3
Gain/(Loss) Reclassified from AOCL to Income	1.0	(6.2)	5.2	(19.3)
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	0.0	0.0	0.0	0.0
Gain/(Loss) Reclassified from AOCL to Income	(1.6)	(1.9)	(3.1)	(3.8)
Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	1.6	15.3	(4.5)	10.0
Gain/(Loss) Reclassified from AOCL to Income	2.6	(6.1)	8.3	(12.5)
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	0.5	0.0	(0.1)	0.0
Gain/(Loss) Reclassified from AOCL to Income	0.0	0.0	0.0	0.0
Cross-currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(Loss) Recognized in OCI (effective portion)	0.0	1.7	0.0	(1.7)
Gain/(Loss) Reclassified from AOCL to Income	$ 0.0	$ 1.8	$ 0.0	$ (3.0)