Investments (Schedule Of Ownership Positions In Significant Unconsolidated Investments) (Details)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Nippon Aluminum Alkyls [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in joint ventures	50.00%	50.00%	50.00%
Magnifin Magnesiaprodukte GmbH & Co. KG [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in joint ventures	50.00%	50.00%	50.00%
Nippon Ketjen Company Limited [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in joint ventures	50.00%	50.00%	50.00%
Eurecat S.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in joint ventures	50.00%	50.00%	50.00%
Fabrica Carioca de Catalisadores S.A. [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in joint ventures	50.00%	50.00%	50.00%
Stannica, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of interest in joint ventures	50.00%	50.00%