Accrued Environmental Remediation Costs (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accrued Environmental Remediation Costs [Line Items]
Accrued Environmental Remediation Costs	$ 11,458	$ 11,987
Continuing Operations
Accrued Environmental Remediation Costs [Line Items]
Accrued Environmental Remediation Costs	5,666	6,335
Retained From Former Chemicals Business
Accrued Environmental Remediation Costs [Line Items]
Accrued Environmental Remediation Costs	$ 5,792	$ 5,652