XML 57 R72.htm IDEA: XBRL DOCUMENT v2.4.0.8
Related Party Transactions - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Dec. 31, 2013
Related Party Transaction [Line Items]      
Net sales to related parties $ 279 $ 278  
Accounts payable to related parties 110   73
Outside processing services
     
Related Party Transaction [Line Items]      
Purchases from related parties 15 19  
Taconite pellets
     
Related Party Transaction [Line Items]      
Purchases from related parties 54 64  
PRO-TEC Coating Company
     
Related Party Transaction [Line Items]      
Accounts payable to related parties 99   70
Other equity investees
     
Related Party Transaction [Line Items]      
Accounts payable to related parties $ 11   $ 3