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Fair Value Of Financial Instruments (Narrative) (Detail) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | ||||||||
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Sep. 30, 2012
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Sep. 30, 2011
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Jun. 30, 2011
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Sep. 30, 2012
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Sep. 30, 2011
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Dec. 31, 2011
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Sep. 30, 2012
Empire [Member]
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Dec. 31, 2011
Empire [Member]
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Dec. 31, 2002
Empire [Member]
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Dec. 31, 2002
Prior [Member]
Empire [Member]
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Dec. 31, 2002
Current [Member]
Empire [Member]
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Sep. 30, 2012
U.S. Iron Ore [Member]
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Dec. 31, 2011
U.S. Iron Ore [Member]
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| Fair Value, Assets And Liabilities Components [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Management Estimate of 62% Fe | Ìý | Ìý | Ìý | 62.00% | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Transfer of derivative assets from level 3 to level 2 | $ 0 | $ 0 | $ 20.0 | $ 0 | $ 20.0 | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Maximum deferred portion of supplemental payments | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 22.3 | Ìý |
| Debt Instrument, Interest Rate, Stated Percentage | 9.00% | Ìý | Ìý | 9.00% | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Interest rate on long term receivables | Ìý | Ìý | Ìý | prime rate | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Debt Instrument, Basis Spread on Variable Rate | 3.50% | Ìý | Ìý | 3.50% | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Other non-current assets | 170.4 | Ìý | Ìý | 170.4 | Ìý | 191.2 | Ìý | Ìý | Ìý | Ìý | Ìý | 5.6 | 22.3 |
| Fair value of the receivable | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 23.5 | 30.7 | Ìý | Ìý | Ìý | 5.2 | 20.8 |
| Estimated credit-adjusted risk-free interest rate | Ìý | Ìý | Ìý | 3.31% | Ìý | 2.12% | Ìý | Ìý | Ìý | Ìý | Ìý | 3.30% | 3.29% |
| Percent ownership interest | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 46.70% | 79.00% | Ìý | Ìý |
| Long term accounts notes and loans receivable net noncurrent | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 21.2 | 26.5 | 120.0 | Ìý | Ìý | Ìý | Ìý |
| Notes, Loans and Financing Receivable, Net, Current | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 10.0 | $ 10.0 | Ìý | Ìý | Ìý | Ìý | Ìý |
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- Details
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- Definition
Management Estimate of 62% Fe No definition available.
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- Definition
Maximum deferred portion of supplemental payments No definition available.
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- Definition
This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. Amounts due from customers or clients for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, as well as any other amounts due from others, including related parties, which may be included in accounts receivable as categorized on the statement of financial position. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The percentage points added to the reference rate to compute the variable rate on the debt instrument. No definition available.
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- Definition
The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. No definition available.
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- Definition
Interest rate stated in the contractual debt agreement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Risk-free interest rate assumption used in valuing an instrument. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The aggregate of amounts due from customers or clients more than one year from the balance sheet date, for goods or services that have been delivered or sold in the normal course of business and an amount representing an agreement for an unconditional promise by the maker to pay the Company (holder) a definite sum of money at a future date more than one year from the balance sheet date, reduced to their estimated net realizable fair value by an allowance established by the Company of the amount it deems uncertain of collection and net of any write-downs taken for collection uncertainty on the part of the holder, respectively. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
An amount representing an agreement for an unconditional promise by the maker to pay the Company (holder) a definite sum of money within one year from the balance sheet date (or the normal operating cycle, whichever is longer), net of any write-downs taken for collection uncertainty on the part of the holder. Such amount may include accrued interest receivable in accordance with the terms of the debt. The debt also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. This amount does not include amounts related to receivables held-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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