SEGMENT REPORTING (Schedule Of Segment Reporting Information, By Segment) (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Revenues from product sales and services | $ 600.9 | $ 698.4 | $ 569.3 | $ 461.6 | $ 754.0 | $ 553.3 | $ 496.2 | $ 305.5 | $ 2,330.2 | $ 2,109.0 | $ 2,013.3 |
| Revenues from producet sales and services, percent | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 100.00% | 100.00% | 100.00% |
| SALES MARGIN | $ 100.7 | $ 160.2 | $ 145.1 | $ 95.7 | $ 181.5 | $ 85.4 | $ 91.5 | 30.9 | $ 501.7 | $ 389.3 | $ 236.5 |
| Other operating expense | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (78.1) | (148.5) | (85.2) |
| TOTAL OTHER INCOME (EXPENSE) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (294.2) | (33.8) | 161.8 |
| Income from continuing operations before income taxes and equity loss from ventures | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 129.4 | 207.0 | 313.1 |
| Net income (loss) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 363.1 | 199.3 | (748.4) |
| Interest expense, net | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (132.0) | (200.5) | (228.5) |
| Interest Income (Expense), net, including Discontinued Operations | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (231.4) |
| Income Tax Expense (Benefit) | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (252.4) | (12.2) | 169.3 |
| Income Tax Expense (Benefit), including Discontinued Operations | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (163.3) |
| Depreciation, depletion and amortization | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (87.7) | (115.4) | (134.0) |
| EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 330.4 | 503.0 | (219.7) |
| Gain (loss) on extinguishment/restructuring of debt | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 174.3 | (165.4) | 166.3 | 392.9 |
| LOSS FROM DISCONTINUED OPERATIONS, net of tax | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (18.7) | (19.9) | (892.1) |
| Impairment of other long-lived assets | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 0.0 | 0.0 | (3.3) |
| Adjusted EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 504.9 | 373.5 | 292.9 |
| Depreciation, Depletion and Amortization excluding Depreciation, Amortization and Depletion expense for Discontinued Operations | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 87.7 | 115.4 | 130.8 |
| Capital Additions | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 156.0 | 68.5 | 72.2 |
| U.S. Iron Ore [Member] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Revenues from product sales and services | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 1,866.0 | $ 1,554.5 | $ 1,525.4 |
| Revenues from producet sales and services, percent | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 80.00% | 74.00% | 76.00% |
| SALES MARGIN | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 465.4 | $ 275.7 | $ 227.1 |
| Depreciation, depletion and amortization | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (66.6) | (84.0) | (98.9) |
| EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 534.9 | 342.4 | 317.6 |
| Adjusted EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 559.4 | 359.6 | 352.1 |
| Capital Additions | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 136.8 | 62.2 | 58.2 |
| Asia Pacific Iron Ore [Member] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Revenues from product sales and services | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 464.2 | $ 554.5 | $ 487.9 |
| Revenues from producet sales and services, percent | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 20.00% | 26.00% | 24.00% |
| SALES MARGIN | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ 36.3 | $ 113.6 | $ 9.4 |
| Depreciation, depletion and amortization | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (14.3) | (25.1) | (25.3) |
| EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 40.7 | 128.3 | 35.3 |
| Adjusted EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 50.4 | 132.9 | 32.7 |
| Capital Additions | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 2.8 | 0.2 | 5.4 |
| All Other Segments [Member] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Depreciation, depletion and amortization | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (6.8) | (6.3) | (6.6) |
| Capital Additions | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 16.4 | 6.1 | 8.6 |
| Other Segment [Member] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (245.2) | 32.3 | (572.6) |
| Adjusted EBITDA | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (104.9) | (119.0) | (91.9) |
| EBITDA Calculation [Member] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Depreciation, depletion and amortization | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (87.7) | (115.4) | (134.0) |
| Adjusted EBITDA Calculation [Member] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Segment Reporting Information [Line Items] | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý |
| Impact of Discontinued Operations | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | (892.0) |
| Foreign Exchange Remeasurement | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 11.4 | (16.8) | 16.3 |
| Severance Costs | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | 0.0 | (0.1) | (10.2) |
| Inventory Write-down | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | Ìý | $ (1.8) | $ 0.0 | $ (16.3) |
| X | ||||||||||
- Definition Adjusted Earnings Before Interest, Taxes and Depreciation, Depletion and Amortization No definition available.
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- Definition Depreciation, Depletion and Amortization excluding Depreciation, Amortization and Depletion expense for Discontinued Operations No definition available.
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- Definition Earnings before Interest, Taxes, and Depreciation, Depletion and Amortization No definition available.
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- Definition Foreign Exchange Remeasurement No definition available.
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- Definition Impact of Discontinued Operations No definition available.
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- Definition Income Tax Expense (Benefit), including Discontinued Operations No definition available.
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- Definition Interest Income (Expense), net, including Discontinued Operations No definition available.
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- Definition Percentage of Segment Revenue No definition available.
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- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The net amount of operating interest income (expense). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense. No definition available.
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- Definition The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. No definition available.
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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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