Comprehensive Income And Accumulated Other Comprehensive Income - Reclassification out of AOCI (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	$ 9.9	$ 2.4	$ 12.6	$ 18.3
Interest expense, net	(45.9)	(56.4)	(149.0)	(160.5)
Operating expense	691.7	614.0	2,102.2	1,891.0
Selling, general and administrative	291.9	260.3	848.1	801.9
Total before income taxes	512.8	412.8	1,357.6	1,349.4
Provision for income taxes	(130.4)	(100.8)	(289.6)	(282.7)
Net income	382.4	312.0	1,068.0	1,066.7
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Net income	0.2	(0.7)	(1.1)	(2.2)
Gains (losses) on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	(0.1)		(0.2)
Provision for income taxes	0.1		0.1
Net income	0.0	0.1	(0.1)	0.3
Gains (losses) on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income | Cross-currency swap
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	0.1	0.1	0.0	0.3
Provision for income taxes		0.0		0.0
Gains (losses) on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income | Interest rate contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	(0.2)		(0.2)
Gains on net investment hedges | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Provision for income taxes	(0.2)		(0.2)
Net income	0.8		0.8
Gains on net investment hedges | Reclassification out of Accumulated Other Comprehensive Income | FX forwards
Derivative Instruments, Gain (Loss) [Line Items]
Other non-operating income (expense), net	1.0		1.0
Amortization of actuarial losses and prior service costs included in net income | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Operating expense	(0.5)	(0.6)	(1.5)	(2.2)
Selling, general and administrative	(0.3)	(0.5)	(0.9)	(1.3)
Pension and other retirement benefits | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Total before income taxes	(0.8)	(1.1)	(2.4)	(3.5)
Provision for income taxes	0.2	0.3	0.6	1.0
Net income	$ (0.6)	$ (0.8)	$ (1.8)	$ (2.5)