Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v2.4.1.9
Document and Entity Information (USD $)
12 Months Ended
Dec. 31, 2014
Feb. 23, 2015
Jun. 30, 2014
Document and Entity Information [Abstract]      
Entity Registrant Name CLIFFS NATURAL RESOURCES INC.    
Entity Central Index Key 0000764065    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Document Type 10-K    
Document Period End Date Dec. 31, 2014    
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   153,279,552dei_EntityCommonStockSharesOutstanding  
Trading Symbol clf    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 2,397,182,297dei_EntityPublicFloat