|
INCOME TAXES INCOME TAXES (Income Taxes for Other than Continuing Operations) (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2012
|
|
| Income Tax Contingency [Line Items] | |||
| Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax | $ 39.8us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax | $ 100.0us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax | $ 13.8us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax |
| Other Comprehensive Income Unrealized Gain Loss On Mark To Market Adjustments Arising During Period Tax | 3.6clf_OtherComprehensiveIncomeUnrealizedGainLossOnMarkToMarketAdjustmentsArisingDuringPeriodTax | 2.0clf_OtherComprehensiveIncomeUnrealizedGainLossOnMarkToMarketAdjustmentsArisingDuringPeriodTax | 1.7clf_OtherComprehensiveIncomeUnrealizedGainLossOnMarkToMarketAdjustmentsArisingDuringPeriodTax |
| Other Comprehensive Income (Loss), Other Tax | (1.1)clf_OtherComprehensiveIncomeLossOtherTax | (12.4)clf_OtherComprehensiveIncomeLossOtherTax | 2.6clf_OtherComprehensiveIncomeLossOtherTax |
| Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent | 42.3us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1 | 89.6us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1 | 18.1us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1 |
| Income Tax Effects Allocated Directly To Equity, Equity Transactions, Acquisition of Noncontrolling Interest | 0clf_IncomeTaxEffectsAllocatedDirectlyToEquityEquityTransactionsAcquisitionofNoncontrollingInterest | 102.1clf_IncomeTaxEffectsAllocatedDirectlyToEquityEquityTransactionsAcquisitionofNoncontrollingInterest | 0clf_IncomeTaxEffectsAllocatedDirectlyToEquityEquityTransactionsAcquisitionofNoncontrollingInterest |
| Income Tax Effects Allocated Directly to Equity, Equity Transactions | (4.8)us-gaap_IncomeTaxEffectsAllocatedDirectlyToEquityEquityTransactions | 3.5us-gaap_IncomeTaxEffectsAllocatedDirectlyToEquityEquityTransactions | (12.8)us-gaap_IncomeTaxEffectsAllocatedDirectlyToEquityEquityTransactions |
| Income Tax Refunds, Discontinued Operations | $ 0us-gaap_IncomeTaxRefundsDiscontinuedOperations | $ (2.0)us-gaap_IncomeTaxRefundsDiscontinuedOperations | $ 10.4us-gaap_IncomeTaxRefundsDiscontinuedOperations |
| X | ||||||||||
|
- Definition
Income Tax Effects Allocated Directly To Equity, Equity Transactions, Acquisition of Noncontrolling Interest No definition available.
|
| X | ||||||||||
|
- Definition
Other Comprehensive Income (Loss), Other Tax No definition available.
|
| X | ||||||||||
|
- Definition
Tax effect on the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's increase (decrease) in deferred hedging gains or losses No definition available.
|
| X | ||||||||||
|
- Details
|
| X | ||||||||||
|
- Definition
The tax effect of an increase or decrease in contributed capital (for example, deductible expenditures reported as a reduction of the proceeds from issuing capital stock) during the period charged or credited directly to shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
The amount of cash received during the period as refunds for the overpayment of taxes from discontinued operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of tax (expense) benefit, after reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
|
- Definition
Amount of tax expense (benefit) allocated to other comprehensive income (loss) attributable to parent entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|