Legal Proceedings And Contingent Liabilities (Narrative) (Details)	2 Months Ended	6 Months Ended
	Apr. 09, 2008	Nov. 30, 2011
Loss Contingencies [Line Items]
Average level of hexavalent chromium, nanograms per cubic meter	2.43	1.00
SCAQMD calculation of cancer risk, time frame assumption, in years		70
Number of subsidiary defendants in class action lawsuit		3
Assuming Continuous Exposure For Seventy Years [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Increase in risk of cancer, instances per million people		500
Assuming Continuous Exposure For Seventy Years [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Increase in risk of cancer, instances per million people		250
Shellman Lawsuit [Member]
Loss Contingencies [Line Items]
Number of additional class action lawsuits filed		5
Number of lawsuits stayed		4
Crestmore Plant [Member]
Loss Contingencies [Line Items]
Number of individual plaintiffs involved in lawsuit		3,000
Number of plaintiffs dismissed by court		2,000
Oro Grande Plant [Member]
Loss Contingencies [Line Items]
Number of individual plaintiffs involved in lawsuit		300
Number of plaintiffs dismissed by court		250