Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 11,384.4
Total other comprehensive income (loss), net of tax	$ 53.4	$ 0.2	273.2	$ (47.2)
Ending balance	12,770.0		12,770.0
Cumulative Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(607.9)
Other comprehensive (loss) income before reclassifications			216.9
Amounts reclassified to earnings			87.4
Total other comprehensive income (loss), net of tax			304.3
Ending balance	(303.6)		(303.6)
Pension and Postretirement Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(400.0)
Other comprehensive (loss) income before reclassifications			(10.2)
Amounts reclassified to earnings			8.7
Total other comprehensive income (loss), net of tax			(1.5)
Ending balance	(401.5)		(401.5)
Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(36.9)
Other comprehensive (loss) income before reclassifications			(29.7)
Amounts reclassified to earnings			0.1
Total other comprehensive income (loss), net of tax			(29.6)
Ending balance	(66.5)		(66.5)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(1,044.8)
Other comprehensive (loss) income before reclassifications			177.0
Amounts reclassified to earnings			96.2
Total other comprehensive income (loss), net of tax			273.2
Ending balance	$ (771.6)		$ (771.6)