Accrued Environmental Remediation Costs (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accrued Environmental Remediation Costs
Accrued Environmental Remediation Costs	$ 11,987	$ 10,783
Retained from former Chemicals business [Member]
Accrued Environmental Remediation Costs
Accrued Environmental Remediation Costs	5,652	4,645
Continuing operations [Member]
Accrued Environmental Remediation Costs
Accrued Environmental Remediation Costs	$ 6,335	$ 6,138