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SEGMENT REPORTING Segment Reporting (Summary of Assets by Segment) (Details) (USD $)
In Millions, unless otherwise specified |
Mar. 31, 2013
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Dec. 31, 2012
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|---|---|---|
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | $ 13,821.9 | $ 13,574.9 |
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U.S. Iron Ore [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | 1,848.4 | 1,735.1 |
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Eastern Canadian Iron Ore [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | 7,719.7 | 7,605.1 |
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Asia Pacific Iron Ore [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | 1,474.4 | 1,506.3 |
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North American Coal [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | 1,829.7 | 1,877.8 |
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All Other Segments [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | 599.3 | 570.9 |
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Total Segment Assets [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | 13,471.5 | 13,295.2 |
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Corporate [Member]
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Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý |
| Assets | $ 350.4 | $ 279.7 |
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- Definition
Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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