Segment Reporting (Schedule Of Concentrations In Revenue) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Percentage of Total Revenue	100.00%	100.00%	100.00%
Iron Ore [Member]
Percentage of Total Revenue	85.00%	81.00%	81.00%
Coal [Member]
Percentage of Total Revenue	11.00%	13.00%	14.00%
Reimbursement Revenue And Freight Revenue [Member]
Percentage of Total Revenue	4.00%	6.00%	5.00%