|
GOODWILL AND OTHER INTANGIBLE ASSETS AND LIABILITIES (Narrative) (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Impairment Loss | $ 80.9 | $ 1,000.0 | Ìý |
| Product | 5,346.6 | 5,520.9 | 6,321.3 |
| Below-market sales contracts, remaining contract life | 3 years | Ìý | Ìý |
| Assets, Fair Value Disclosure, Nonrecurring | 47.9 | 72.5 | Ìý |
| Impairment Charges | 318.4 | 1,415.3 | Ìý |
|
Cost of Sales [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Amortization expense relating to intangible assets | 19.9 | 22.5 | 17.7 |
|
Product Revenues [Member] | Sales Revenue, Goods, Net [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Product | 45.9 | 46.3 | 57.0 |
|
Cliffs Chromite Ontario and Cliffs Chromite Far North [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Impairment Loss | 80.9 | Ìý | Ìý |
|
Wabush and Cliffs Chromite Ontario and Cliffs Chromite Far North [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | 46.3 | Ìý | Ìý |
| Impairment of Long-Lived Assets Held-for-use | 155.4 | Ìý | Ìý |
|
CQIM Reporting Unit [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | 0 | 0 | Ìý |
| Goodwill, Impairment Loss | Ìý | 997.3 | Ìý |
|
Wabush [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | Ìý | 0 | Ìý |
| Impairment of Intangible Assets, Finite-lived | 9.5 | Ìý | Ìý |
| Goodwill, Impairment Loss | Ìý | 2.7 | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | Ìý | 0 | Ìý |
| Impairment of Long-Lived Assets Held-for-use | 140.1 | 49.9 | Ìý |
| Finite-lived Intangible Assets, Fair Value Disclosure | 1.6 | Ìý | Ìý |
| Other Asset Impairment Charges | 14.5 | Ìý | Ìý |
|
Fair Value, Inputs, Level 1 [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Assets, Fair Value Disclosure, Nonrecurring | 0 | 0 | Ìý |
|
Fair Value, Inputs, Level 1 [Member] | Wabush and Cliffs Chromite Ontario and Cliffs Chromite Far North [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | 0 | Ìý | Ìý |
|
Fair Value, Inputs, Level 1 [Member] | CQIM Reporting Unit [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | 0 | 0 | Ìý |
|
Fair Value, Inputs, Level 1 [Member] | Wabush [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | Ìý | 0 | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | Ìý | 0 | Ìý |
| Finite-lived Intangible Assets, Fair Value Disclosure | 0 | Ìý | Ìý |
|
Fair Value, Inputs, Level 2 [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Assets, Fair Value Disclosure, Nonrecurring | 0 | 0 | Ìý |
|
Fair Value, Inputs, Level 2 [Member] | Wabush and Cliffs Chromite Ontario and Cliffs Chromite Far North [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | 0 | Ìý | Ìý |
|
Fair Value, Inputs, Level 2 [Member] | CQIM Reporting Unit [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | 0 | 0 | Ìý |
|
Fair Value, Inputs, Level 2 [Member] | Wabush [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | Ìý | 0 | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | Ìý | 0 | Ìý |
| Finite-lived Intangible Assets, Fair Value Disclosure | 0 | Ìý | Ìý |
|
Fair Value, Inputs, Level 3 [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Assets, Fair Value Disclosure, Nonrecurring | 47.9 | 72.5 | Ìý |
|
Fair Value, Inputs, Level 3 [Member] | Wabush and Cliffs Chromite Ontario and Cliffs Chromite Far North [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | 46.3 | Ìý | Ìý |
|
Fair Value, Inputs, Level 3 [Member] | CQIM Reporting Unit [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | 0 | 0 | Ìý |
|
Fair Value, Inputs, Level 3 [Member] | Wabush [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Goodwill, Fair Value Disclosure | Ìý | 0 | Ìý |
| Property, Plant, and Equipment, Fair Value Disclosure | Ìý | 0 | Ìý |
| Finite-lived Intangible Assets, Fair Value Disclosure | 1.6 | Ìý | Ìý |
|
Amapa [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Equity Method Investments, Fair Value Disclosure | 0 | 72.5 | Ìý |
| Equity Method Investment, Other than Temporary Impairment | 67.6 | 365.4 | Ìý |
|
Amapa [Member] | Fair Value, Inputs, Level 1 [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Equity Method Investments, Fair Value Disclosure | 0 | 0 | Ìý |
|
Amapa [Member] | Fair Value, Inputs, Level 2 [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Equity Method Investments, Fair Value Disclosure | 0 | 0 | Ìý |
|
Amapa [Member] | Fair Value, Inputs, Level 3 [Member]
|
Ìý | Ìý | Ìý |
| Goodwill [Line Items] | Ìý | Ìý | Ìý |
| Equity Method Investments, Fair Value Disclosure | $ 0 | $ 72.5 | Ìý |