Restructuring and Other - Schedule of Changes in the Restructuring Reserve (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]
Balance at the beginning			$ 23.5
Restructuring Charges	$ 9.4	$ 11.8	23.2	$ 23.3
Foreign Exchange and Other			0.8
Cash Paid			(24.2)
Balance at the end	23.3		23.3
Employee terminations
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			9.6
Restructuring Charges			11.2
Foreign Exchange and Other			(0.5)
Cash Paid			(14.2)
Balance at the end	6.1		6.1
Multi-employer pension plan withdrawal obligations
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			11.0
Restructuring Charges			0.5
Cash Paid			(1.1)
Balance at the end	10.4		10.4
Lease terminations and other
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			2.9
Restructuring Charges			11.5
Foreign Exchange and Other			1.3
Cash Paid			(8.9)
Balance at the end	$ 6.8		$ 6.8