|
INCOME TAXES INCOME TAXES (Schedule of Deferred Tax Assets and Liabilities by Location) (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2014
|
Dec. 31, 2013
|
|---|---|---|
| Income Tax Contingency [Line Items] | ||
| Deferred Tax Liabilities, Net, Noncurrent | $ 51.3us-gaap_DeferredTaxLiabilitiesNoncurrent | $ 1,146.5us-gaap_DeferredTaxLiabilitiesNoncurrent |
| Deferred Tax Assets, Net | 124.8us-gaap_DeferredTaxAssetsLiabilitiesNet | (1,074.5)us-gaap_DeferredTaxAssetsLiabilitiesNet |
| Foreign [Member] | ||
| Income Tax Contingency [Line Items] | ||
| Income tax receivable |
2.2us-gaap_DeferredTaxAssetsNetCurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
29.4us-gaap_DeferredTaxAssetsNetCurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
| Deferred Tax Assets, Net of Valuation Allowance, Noncurrent |
12.0us-gaap_DeferredTaxAssetsNetNoncurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
41.5us-gaap_DeferredTaxAssetsNetNoncurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
| Deferred Tax Liabilities, Net, Noncurrent |
51.3us-gaap_DeferredTaxLiabilitiesNoncurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
971.2us-gaap_DeferredTaxLiabilitiesNoncurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
| Deferred Tax Liabilities, Net, Current |
4.0us-gaap_DeferredTaxLiabilitiesCurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
6.1us-gaap_DeferredTaxLiabilitiesCurrent / clf_RegionReportingInformationByRegionAxis = clf_ForeignMember |
| United States and Foreign [Member] | ||
| Income Tax Contingency [Line Items] | ||
| Deferred Tax Assets |
180.1clf_DeferredTaxAssets / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesAndForeignMember |
78.1clf_DeferredTaxAssets / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesAndForeignMember |
| Deferred Tax Liability |
55.3clf_DeferredTaxLiability / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesAndForeignMember |
1,152.6clf_DeferredTaxLiability / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesAndForeignMember |
| United States [Member] | ||
| Income Tax Contingency [Line Items] | ||
| Income tax receivable |
165.9us-gaap_DeferredTaxAssetsNetCurrent / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesMember |
7.2us-gaap_DeferredTaxAssetsNetCurrent / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesMember |
| Deferred Tax Liabilities, Net, Noncurrent |
$ 0us-gaap_DeferredTaxLiabilitiesNoncurrent / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesMember |
$ 175.3us-gaap_DeferredTaxLiabilitiesNoncurrent / clf_RegionReportingInformationByRegionAxis = clf_UnitedStatesMember |
| X | ||||||||||
|
- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, evaluated and aggregated by country No definition available.
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances, evaluated and aggregated by country. No definition available.
|
| X | ||||||||||
|
- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount after allocation of valuation allowances of noncurrent deferred tax asset attributable to deductible temporary differences and carryforwards. 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
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances 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
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Details
|