Restructuring Costs - Schedule of Accrued Restructuring Costs Activity (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Beginning balance	$ 93.8
Restructuring Costs, Net	7.9	$ 13.3
Payments	(21.4)
Foreign Currency and Other	0.5
Ending balance	80.8
Employee Severance, Termination Benefits and Relocation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	62.8
Restructuring Costs, Net	8.1
Payments	(18.2)
Foreign Currency and Other	0.5
Ending balance	53.2
Exited Contractual Commitments and Other [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	31.0
Restructuring Costs, Net	(0.2)
Payments	(3.2)
Ending balance	$ 27.6