Restructuring, Impairment and Other Charges - Schedule of Changes in the Restructuring Reserve (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			$ 21.0
Restructuring Charges	$ 11.8	$ 10.3	23.3	$ 23.6
Foreign Exchange and Other			1.1
Cash Paid			(17.4)
Balance at the end	28.0		28.0
Employee terminations
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			7.6
Restructuring Charges			19.5
Cash Paid			(13.5)
Balance at the end	13.6		13.6
Lease terminations and other
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			1.6
Restructuring Charges			3.2
Foreign Exchange and Other			1.2
Cash Paid			(2.8)
Balance at the end	3.2		3.2
Multi-employer pension plan withdrawal obligations
Restructuring Cost And Reserve [Line Items]
Balance at the beginning			11.8
Restructuring Charges			0.6
Foreign Exchange and Other			(0.1)
Cash Paid			(1.1)
Balance at the end	$ 11.2		$ 11.2