Quarterly report pursuant to Section 13 or 15(d)

Basis Of Presentation And Significant Accounting Policies (Narrative) (Details)

v2.3.0.15
Basis Of Presentation And Significant Accounting Policies (Narrative) (Details)
In Millions, except Per Share data, unless otherwise specified
3 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 3 Months Ended 6 Months Ended 9 Months Ended
Sep. 30, 2011
USD ($)
Sep. 30, 2010
USD ($)
Sep. 30, 2011
USD ($)
Sep. 30, 2010
USD ($)
Dec. 31, 2010
USD ($)
Sep. 30, 2011
RenewaFUEL [Member]
USD ($)
Sep. 30, 2010
RenewaFUEL [Member]
USD ($)
Sep. 30, 2011
RenewaFUEL [Member]
USD ($)
Sep. 30, 2010
RenewaFUEL [Member]
USD ($)
Sep. 30, 2011
Empire [Member]
USD ($)
Jun. 30, 2011
AusQuest [Member]
USD ($)
Sep. 30, 2011
WISCO [Member]
Sep. 30, 2011
Consolidated Thompson [Member]
May 12, 2011
Consolidated Thompson [Member]
CAD
Sep. 30, 2011
Earnings Per Share, Basic [Member]
USD ($)
Sep. 30, 2011
Immaterial Error [Member]
USD ($)
Jun. 30, 2011
Immaterial Error [Member]
USD ($)
Mar. 31, 2011
Immaterial Error [Member]
USD ($)
Jun. 30, 2011
Immaterial Error [Member]
USD ($)
Sep. 30, 2011
Immaterial Error [Member]
USD ($)
Cost per share acquired                           17.25            
Ownership percentage in Consolidated Thompson                         100.00%              
Recorded impairment charges                     $ 17.6                  
Interest Percentage                       25.00%                
Fair value of AusQuest closing market price         22.0           7.3                  
Cost of Rehabilitation, Current 20   20                                  
Investment Owned, Balance, Shares                     68.3                  
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest 758.8 298.1 1,609.4 637.4                       16.1 7.7 8.4 16.1 16.1
Earnings Per Share, Basic and Diluted                               $ 0.47 $ (0.22) $ (0.28) $ (0.49)  
Basic $ 4.09 $ 2.20 $ 10.18 $ 4.70                               $ 0.49
Diluted $ 4.07 $ 2.18 $ 10.12 $ 4.67                               $ 0.48
Net income (loss) attributable to Cliffs shareholders 589.5 297.4 1,420.6 635.4                       67.9 (30.4) (37.5) (67.9) 67.9
Retained Earnings (Accumulated Deficit) 4,266.2   4,266.2   2,924.1                     67.9       67.9
LESS: NET INCOME (LOSS) ATTRIBUTABLE TO NONCONTROLLING INTEREST (net of tax of $0.1, $0.3, and $9.1 in 2010, 2009 and 2008) 151.8   170.1                           38.1 45.9 84.0 84.0
NONCONTROLLING INTEREST 1,128.4   1,128.4   (7.2)                     84.0       84.0
Reimbursement Revenue And Freight Revenue 18.4 58.8 169.4 183.1                       (46.0) (46.0)   (46.0) (46.0)
Sales Revenue, goods, net 2,124.4 1,287.2 4,962.4 3,074.8                       54.1 46.0 54.1 100.1 54.1
Related party revenue 224.9   313.6                                  
Related party receivables 68.8   68.8                                  
Total Related Party Revenue 837.8 379.4 1,700.0 905.4           157.1                    
Loss from discontinued operations, net of tax 17.5 0.7 18.7 2.0   17.5 0.7 18.7 2.0                      
Discontinued Operation, Tax Effect of Discontinued Operation           7.3 0.4 7.9 1.0                      
Impairment charge           16.7   16.7                        
Asset Impairment Charges, Tax Effect           7.1   7.1                        
Adjustment to income from continuing operations before income taxes and equity loss from ventures     22.0 12.3                                
Adjustment to net income attributable to shareholders     16.1 8.9                                
Adjustment to basic and diluted earnings per common share     $ 0.12                       $ 0.07          
Adjustment to retained earnings     16.1                                  
Accumulated other comprehensive income         $ 25.3