Quarterly report pursuant to Section 13 or 15(d)

Segment Reporting (Narrative) (Details)

v2.4.0.6
Segment Reporting (Narrative) (Details)
3 Months Ended
Mar. 31, 2012
Eastern Canadian Iron Ore [Member]
 
Segment Reporting Information [Line Items]  
Number of mines 2
U.S. Iron Ore [Member]
 
Segment Reporting Information [Line Items]  
Number of mines 5
Metallurgical Coal Mines [Member]
 
Segment Reporting Information [Line Items]  
Number of mines 5
Thermal Coal Mines [Member]
 
Segment Reporting Information [Line Items]  
Number of mines 1
Amapa [Member] | Latin American Iron Ore [Member]
 
Segment Reporting Information [Line Items]  
Percent ownership interest 30.00%
Sonoma [Member] | Asia Pacific Coal [Member]
 
Segment Reporting Information [Line Items]  
Ownership interest, percent 45.00%