Annual report pursuant to Section 13 and 15(d)

Debt And Credit Facilities (Narrative) (Details)

v2.4.0.6
Debt And Credit Facilities (Narrative) (Details)
6 Months Ended 12 Months Ended 12 Months Ended 12 Months Ended 0 Months Ended 1 Months Ended 0 Months Ended 0 Months Ended
Dec. 31, 2011
USD ($)
Dec. 31, 2011
USD ($)
years
months
Dec. 31, 2010
USD ($)
Mar. 31, 2011
USD ($)
Sep. 20, 2010
USD ($)
Oct. 29, 2009
USD ($)
Dec. 31, 2011
Senior Notes30 Year Tranche [Member]
Mar. 31, 2011
Senior Notes30 Year Tranche [Member]
USD ($)
Sep. 20, 2010
Senior Notes30 Year Tranche [Member]
USD ($)
Dec. 31, 2011
Senior Notes10 Year Tranche [Member]
Mar. 31, 2011
Senior Notes10 Year Tranche [Member]
USD ($)
Sep. 20, 2010
Senior Notes10 Year Tranche [Member]
USD ($)
Sep. 22, 2010
Revolving Credit Facility [Member]
USD ($)
Mar. 31, 2010
Revolving Credit Facility [Member]
USD ($)
Dec. 31, 2011
Revolving Credit Facility [Member]
USD ($)
Aug. 11, 2011
Revolving Credit Facility [Member]
USD ($)
Dec. 31, 2010
Revolving Credit Facility [Member]
USD ($)
Aug. 11, 2011
Credit Facility Amendment [Member]
Sep. 30, 2010
Senior Notes 700 Million Due 2021 [Member]
USD ($)
Dec. 31, 2011
Unsecured Credit Facility [Member]
USD ($)
Aug. 11, 2011
Unsecured Credit Facility [Member]
USD ($)
Dec. 31, 2011
Senior Notes Due 2013 [Member]
USD ($)
Jun. 25, 2008
Senior Notes Due 2013 [Member]
USD ($)
Jun. 25, 2008
Senior Notes Due 2015 [Member]
USD ($)
May 27, 2010
Amapa's Debt [Member]
USD ($)
Aug. 11, 2011
Term Loan [Member]
USD ($)
Dec. 31, 2011
Asia Pacific Iron Ore [Member]
Credit Facility Amendment [Member]
USD ($)
Dec. 31, 2011
Asia Pacific Iron Ore [Member]
Credit Facility Amendment [Member]
AUD
Dec. 31, 2011
Consolidated Thompson [Member]
USD ($)
Aug. 11, 2011
Consolidated Thompson [Member]
USD ($)
May 10, 2011
Consolidated Thompson [Member]
USD ($)
Mar. 31, 2010
Cliffs Natural Resources Pty Ltd [Member]
Credit Facility Amendment [Member]
USD ($)
Mar. 31, 2010
Cliffs Natural Resources Pty Ltd [Member]
Credit Facility Amendment [Member]
AUD
Jun. 25, 2008
Senior Notes [Member]
USD ($)
Apr. 13, 2011
Senior Notes [Member]
Consolidated Thompson [Member]
USD ($)
Jun. 25, 2008
Senior Notes 325 Million [Member]
May 17, 2010
Senior Notes 400 Million [Member]
Mar. 17, 2010
Senior Notes 400 Million [Member]
USD ($)
Aug. 11, 2011
Scenario, Previously Reported [Member]
Multicurrency credit agreement [Member]
USD ($)
Oct. 29, 2009
Scenario, Previously Reported [Member]
Multicurrency credit agreement [Member]
USD ($)
Line of Credit Facility [Line Items]                                                                                
Line of credit facility capacity                                         $ 1,750,000,000                                      
Increase in letters of credit           50,000,000                                                                    
Increase in basis, Points           50                                                                    
Repayments of debt     200,000,000                   350,000,000 200,000,000                     100,800,000                              
Credit agreement additional borrowings   250,000,000                                                                            
Scheduled principal payment 28,000,000                                                                              
Term loan, length of maturity, years   5                                                                            
Required frequency of principal payments, term loan, months   3                                                                            
Senior notes               300,000,000 500,000,000   700,000,000 500,000,000             500,000,000       270,000,000 55,000,000           250,000,000         125,000,000          
Amended Total Funded Debt to EBITDA threshold                                   3.5                                   3.25        
Face Amount of Senior Long Term Notes       1,000,000,000 1,000,000,000                                 270,000,000                       325,000,000 100,000,000     400,000,000    
Stated interest rate               6.25% 6.25%   4.875% 4.80%                     6.31% 6.59%                     8.50%     5.90%    
Discount interest rate on redemption             40     35                                                            
Premium on principal required to redeem notes       101.00%                                                                        
Redemption price, percent of principal in the event of company redemption   100.00%                                                                     100.00%      
Credit facility                                                           1,750,000,000 750,000,000 40,800,000 40,000,000              
Credit facility long term                               600,000,000       897,200,000           200,000,000                         800,000,000 800,000,000
Outstanding long term loan 972,000,000 972,000,000                                                         1,250,000,000                  
Weighted average interest rate                             1.84%                           2.56%                      
Outstanding bank guarantees under credit facilities                             23,500,000   64,700,000                   25,200,000 24,700,000                        
Credit facility remaining capacity                             1,726,500,000   535,300,000                   15,600,000 15,300,000                        
Letters of Credit Outstanding, Amount           150,000,000                                             95,000,000                      
Maturities of debt instruments in 2012 74,800,000 74,800,000                                                                            
Maturities of debt instruments in 2013 369,700,000 369,700,000                                                                            
Maturities of debt instruments in 2014 124,600,000 124,600,000                                                                            
Maturities of debt instruments in 2015 428,800,000 428,800,000                                                                            
Maturities of debt instruments in 2016 299,100,000 299,100,000                                                                            
Maturities of debt instruments after 2016 $ 2,400,000,000 $ 2,400,000,000