Restructuring Costs - Schedule of Accrued Restructuring Costs Activity (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Beginning balance			$ 79.3
Restructuring Costs, Net	$ 45.7	$ 23.6	51.1	$ 32.9
Payments			(29.8)
Foreign Currency and Other			(17.9)
Ending balance	82.7		82.7
Employee Severance, Termination Benefits and Relocation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance			47.2
Restructuring Costs, Net			32.2
Payments			(22.0)
Foreign Currency and Other			(18.9)
Ending balance	38.5		38.5
Exited Contractual Commitments and Other [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance			32.1
Restructuring Costs, Net			18.9
Payments			(7.8)
Foreign Currency and Other			1.0
Ending balance	$ 44.2		$ 44.2