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 |