Commitments And Contingencies (Details) (USD $) In Millions, unless otherwise specified |
9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | |||||||
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Sep. 30, 2011
MT
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Sep. 30, 2011
Bloom Lake [Member]
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Dec. 31, 2012
Bloom Lake [Member]
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Dec. 31, 2011
Bloom Lake [Member]
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Sep. 30, 2011
Lower War Eagle [Member]
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Dec. 31, 2011
Lower War Eagle [Member]
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Sep. 30, 2011
Koolyanobbing [Member]
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Dec. 31, 2012
Koolyanobbing [Member]
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Dec. 31, 2011
Koolyanobbing [Member]
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Dec. 31, 2010
Koolyanobbing [Member]
MT
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Sep. 30, 2011
Empire [Member]
T
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Sep. 30, 2011
Empire and Tilden [Member]
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Dec. 31, 2012
Empire and Tilden [Member]
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Dec. 31, 2011
Empire and Tilden [Member]
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Sep. 30, 2011
Tilden [Member]
T
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Sep. 30, 2011
Oak Grove [Member]
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Dec. 31, 2011
Oak Grove II [Member]
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| Capital investment committed | Ìý | $ 206.0 | Ìý | Ìý | Ìý | Ìý | $ 246.0 | Ìý | Ìý | Ìý | Ìý | $ 178.0 | Ìý | Ìý | Ìý | $ 31.0 | Ìý |
| Gross post-project production capacity, tons | 8,000,000 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 11,000,000 | 3,000,000 | Ìý | Ìý | Ìý | 2,000,000 | Ìý | Ìý |
| Capital investment paid | Ìý | 65.0 | Ìý | Ìý | 31.0 | Ìý | 133.0 | Ìý | Ìý | Ìý | Ìý | 123.0 | Ìý | Ìý | Ìý | 26.0 | Ìý |
| Capital investment, future payments | Ìý | 615.0 | 68.0 | 73.0 | 49.0 | 10.0 | 272.0 | 46.0 | 67.0 | Ìý | Ìý | 264.0 | 24.0 | 31.0 | Ìý | 55.0 | 5.0 |
| Capital Investment, 2012 scheduled payments | Ìý | Ìý | Ìý | Ìý | $ 8 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
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- Definition =Capital commitments appoved and committed.
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- Definition Future Capital Expenditures Beyond Current Year
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- Definition The gross post capital-project production capacity.
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- Definition The minimum amount the entity agreed to spend under the long-term purchase commitment.
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- Definition The cash outflow for acquisition of or capital improvements of property, plant and equipment, used to produce goods or deliver services, and not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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