Commitments and Contingencies - Summary Of Changes In Accrued Environmental Liabilities - (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accrual For Environmental Loss Contingencies Disclosure [Abstract]
Balance, beginning of period	$ 16.0
Environmental liabilities assumed in business combination		$ 15.3
Revisions and liabilities incurred	0.1	1.0
Payments	(0.4)
Translation and other charges	(0.1)	(0.3)
Balance, end of period	15.6	16.0
Less amount classified as accrued liabilities	(4.0)	(4.3)
Environmental liabilities	$ 11.6	$ 11.7