Quarterly report pursuant to Section 13 or 15(d)

BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details)

v2.4.0.6
BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details)
3 Months Ended 3 Months Ended 12 Months Ended 12 Months Ended
Mar. 31, 2013
Mar. 31, 2013
Empire [Member]
Mar. 31, 2013
Black Label And Black Thor Chromite Deposits [Member]
Mar. 31, 2013
Big Daddy Chromite Deposit [Member]
Mar. 31, 2013
CLCC [Member]
Mar. 31, 2013
Wabush [Member]
Mar. 31, 2013
Bloom Lake [Member]
Mar. 31, 2013
Asia Pacific Iron Ore [Member]
Cockatoo [Member]
USD ($)
Dec. 31, 2012
Asia Pacific Iron Ore [Member]
Cockatoo [Member]
AUD
Mar. 31, 2013
Equity Method Investments [Member]
Amapa [Member]
Mar. 31, 2013
Other Liabilities [Member]
Cockatoo [Member]
Dec. 31, 2012
Sonoma [Member]
Asia Pacific Coal [Member]
AUD
Jul. 10, 2012
Sonoma [Member]
Asia Pacific Coal [Member]
Related Party Transaction [Line Items]                          
Current Fiscal Year End Date --12-31                        
Ownership Interest   79.00% 100.00% 70.00% 100.00% 100.00% 75.00%           45.00%
Ownership interest, equity method investment                   30.00% 50.00%    
Total percentage of Amapa sold                   100.00%      
Proceeds from sale of economic interest (in AUD)                 4.00     141,000,000  
Estimated rehabilitation costs               $ 24,000,000