Business Disposition - Schedule of Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Total	$ 37.6	$ (1.7)
Waste Management
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net sales	4.6	21.5
Operating income (loss)	(0.4)	0.6
Other expense, net		(1.9)
Interest expense, net	(0.3)	(1.2)
Loss before taxes	(0.7)	(2.5)
Income tax expense (benefit)	0.1	(0.8)
Net loss	(0.6)	(1.7)
Pre-tax gain on disposal	58.4
Income tax expense	20.2
After-tax gain on disposal	38.2
Total	37.6	(1.7)
Net cash provided by operating activities	2.3	7.2
Net cash provided by (used in) investing activities	$ (0.1)	$ (0.5)