Plant Closures and Discontinued Operations - Summary of Restructuring Activities and Related Reserves (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	$ 8.1	$ 9.0
Accrual	27.5	13.1
Costs charged against assets	(1.3)
Reversal of accrued charges	(0.3)	(2.0)
Cash paid	(5.1)	(11.0)
Currency translation	(0.7)	(1.0)
Reserve, Ending Balance	28.2	8.1
Severance and Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	0.0	0.1
Accrual	2.2	9.8
Costs charged against assets	0.0
Reversal of accrued charges	0.0	0.0
Cash paid	(0.2)	(9.7)
Currency translation	0.0	(0.2)
Reserve, Ending Balance	2.0	0.0
Environmental Remediation [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	4.1	5.6
Accrual	0.6	0.0
Costs charged against assets	0.0
Reversal of accrued charges	0.0	(1.1)
Cash paid	0.0	0.0
Currency translation	(0.4)	(0.4)
Reserve, Ending Balance	4.3	4.1
Asset Retirement [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	3.9	3.3
Accrual	23.4	3.2
Costs charged against assets	0.0
Reversal of accrued charges	(0.3)	(0.9)
Cash paid	(4.8)	(1.3)
Currency translation	(0.3)	(0.4)
Reserve, Ending Balance	21.9	3.9
Other [Member]
Restructuring Cost and Reserve [Line Items]
Reserve, Beginning Balance	0.1	0.0
Accrual	1.3	0.1
Costs charged against assets	(1.3)
Reversal of accrued charges	0.0	0.0
Cash paid	(0.1)	0.0
Currency translation	0.0	0.0
Reserve, Ending Balance	$ 0.0	$ 0.1