Accounts Payable and Accrued Liabilities - Schedule of Accounts Payable and Accrued Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Schedule Of Other Liabilities [Line Items]
Accounts payable	$ 159.2	$ 169.6
Employee benefits	30.9	38.5
Accrued sales discounts and rebates	9.3	14.9
Environmental remediation and related costs	6.5	7.6
Deferred income	3.7	5.4
Reserve for uncertain tax positions	3.0	3.0
Other	42.4	42.8
Total	303.3	334.6
Contran | Income Taxes
Schedule Of Other Liabilities [Line Items]
Payable to affiliates	1.9	2.6
Contran | Trade Accounts Payables
Schedule Of Other Liabilities [Line Items]
Payable to affiliates	26.5	26.8
LPC
Schedule Of Other Liabilities [Line Items]
Payable to affiliates	$ 19.9	$ 23.4