Restructuring and Other - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Restructuring And Other [Line Items]
Severance costs
Site Remediation Costs	8.7
Charitable contribution			8
Charitable contribution, after income taxes			5.1
Phosphorous Flame Retardant Business Exit
Restructuring And Other [Line Items]
Restructuring charges	94.7		94.7
Restructuring charges, net of tax	73.6		73.6
Phosphorous flame retardants business exit, write off of net asset values	57		57
Write-offs of foreign currency translation adjustments of phosphorous flame retardants business	12		12
Severance costs	13		13
Site Remediation Costs	9.0		9.0
Other estimated exit costs of phosphorous flame retardants business	4		4
Expected restructuring plan completion date	2014		2014
Settlement of Litigation
Restructuring And Other [Line Items]
Gain of settlement of litigation			8.1
Gain of settlement of litigation, after income taxes			5.1
Estimated reimbursement of related legal fees			$ 0.9