Discontinued Operations - Summary Of Restructuring Activities And Related Reserves (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Reserve at December 31, 2011	$ 15.9
Charges	0.5
Costs charged against assets	(0.4)
Reversals	(0.1)
Cash paid	(2.5)
Currency translation	0.4
Reserve at September 30, 2012	13.8
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Reserve at December 31, 2011	1.8
Charges	0.1
Costs charged against assets	0
Reversals	(0.1)
Cash paid	(1.6)
Currency translation	0
Reserve at September 30, 2012	0.2
Environmental Remediation Expense [Member]
Restructuring Cost and Reserve [Line Items]
Reserve at December 31, 2011	6.7
Charges	0
Costs charged against assets	0
Reversals	0
Cash paid	(0.1)
Currency translation	0.2
Reserve at September 30, 2012	6.8
Inventory Writedowns [Member]
Restructuring Cost and Reserve [Line Items]
Reserve at December 31, 2011	0
Charges	0.4
Costs charged against assets	(0.4)
Reversals	0
Cash paid	0
Currency translation	0
Reserve at September 30, 2012	0
Asset Retirement Obligation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Reserve at December 31, 2011	6.2
Charges	0
Costs charged against assets	0
Reversals	0
Cash paid	(0.3)
Currency translation	0.2
Reserve at September 30, 2012	6.1
Other [Member]
Restructuring Cost and Reserve [Line Items]
Reserve at December 31, 2011	1.2
Charges	0
Costs charged against assets	0
Reversals	0
Cash paid	(0.5)
Currency translation	0
Reserve at September 30, 2012	$ 0.7