Restructuring Costs - Schedule of Accrued Restructuring Costs Activity (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Beginning balance			$ 79.3
Restructuring Costs, Net	$ 11.4	$ 35.5	62.5	$ 68.4
Payments			(51.1)
Foreign Currency and Other			(20.2)
Ending balance	70.5		70.5
Employee Severance, Termination Benefits and Relocation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance			47.2
Restructuring Costs, Net			41.1
Payments			(40.3)
Foreign Currency and Other			(21.4)
Ending balance	26.6		26.6
Exited Contractual Commitments and Other [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance			32.1
Restructuring Costs, Net			21.4
Payments			(10.8)
Foreign Currency and Other			1.2
Ending balance	$ 43.9		$ 43.9