Restructuring, Impairment and Other Charges - Other Charges - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Restructuring Cost And Reserve [Line Items]
Other Charges	$ 0.6	$ 0.6	$ 1.2	$ 1.1
Accrued liabilities	409.7		409.7		$ 541.7
Other noncurrent liabilities	183.3		183.3		$ 193.1
Multi-employer pension plan withdrawal obligations
Restructuring Cost And Reserve [Line Items]
Other Charges	0.6	$ 0.6	1.2	$ 1.1
Accrued liabilities	4.9		4.9
Other noncurrent liabilities	$ 33.4		$ 33.4