Annual report pursuant to Section 13 and 15(d)

Statements of Consolidated Changes in Equity

v2.4.1.9
Statements of Consolidated Changes in Equity (USD $)
In Millions, except Share data, unless otherwise specified
Total
USD ($)
Depositary Shares [Member]
USD ($)
Common Stock [Member]
USD ($)
Capital in Excess of Par Value of Shares [Member]
USD ($)
Retained Earnings [Member]
USD ($)
Common Shares in Treasury [Member]
USD ($)
Accumulated Other Comprehensive Income (Loss) [Member]
USD ($)
Noncontrolling Interest [Member]
USD ($)
Depositary Shares [Member]
USD ($)
Depositary Shares [Member]
Capital in Excess of Par Value of Shares [Member]
USD ($)
Common Stock [Member]
Common Stock [Member]
Capital in Excess of Par Value of Shares [Member]
USD ($)
Balance, beginning of period at Dec. 31, 2011 $ 7,039.7us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest   $ 18.5us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
$ 1,770.8us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
$ 4,424.3us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
$ (336.0)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
$ (92.6)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
$ 1,254.7us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Balance, beginning of period (in shares) at Dec. 31, 2011     142,000,000us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]                        
NET INCOME (LOSS) (1,126.6)us-gaap_ProfitLoss       (899.4)us-gaap_ProfitLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
    (227.2)us-gaap_ProfitLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 862.4us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent           37.0us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
         
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest               7.6us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Other Comprehensive Income (Loss), Net of Tax 44.6us-gaap_OtherComprehensiveIncomeLossNetOfTax                      
Pension and OPEB liability, net of tax 33.8us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax                      
Unrealized net loss on marketable securities, net of tax (0.5)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax                      
Total comprehensive income (loss) (1,082.0)us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest             (219.6)us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Purchase of subsidiary shares from noncontrolling interest (2.1)us-gaap_MinorityInterestDecreaseFromRedemptions             (2.1)us-gaap_MinorityInterestDecreaseFromRedemptions
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Undistributed losses to noncontrolling interest to subsidiary 0.4clf_UndistributedEarningsLossesRelatedToNoncontrollingInterests             0.4clf_UndistributedEarningsLossesRelatedToNoncontrollingInterests
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Capital contribution by noncontrolling interest to subsidiary 104.4us-gaap_ProceedsFromMinorityShareholders     1.6us-gaap_ProceedsFromMinorityShareholders
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
      102.8us-gaap_ProceedsFromMinorityShareholders
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Stock Issued During Period, Value, Acquisitions (8.0)us-gaap_StockIssuedDuringPeriodValueAcquisitions             (8.0)us-gaap_StockIssuedDuringPeriodValueAcquisitions
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Stock and other incentive plans (in shares)     500,000us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Stock and other incentive plans 15.7us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation     2.3us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
  13.4us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
           
Common stock dividends ($0.60 per share) (307.2)us-gaap_DividendsCommonStock       (307.2)us-gaap_DividendsCommonStock
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
             
Preferred stock dividends ($1.66 per depositary share) 0us-gaap_DividendsPreferredStock                      
Balance, end of period at Dec. 31, 2012 5,760.9us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest   18.5us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
1,774.7us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
3,217.7us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
(322.6)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
(55.6)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
1,128.2us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Balance, end of period (in shares) at Dec. 31, 2012     142,500,000us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]                        
NET INCOME (LOSS) 361.8us-gaap_ProfitLoss       413.5us-gaap_ProfitLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
    (51.7)us-gaap_ProfitLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent (356.2)us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent           (57.3)us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
         
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest               30.5us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Other Comprehensive Income (Loss), Net of Tax (26.8)us-gaap_OtherComprehensiveIncomeLossNetOfTax                      
Pension and OPEB liability, net of tax 208.3us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax                      
Unrealized net loss on marketable securities, net of tax 3.1us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax                      
Total comprehensive income (loss) 335.0us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest             (21.2)us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Equity offering (in shares)   29,300,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
10,400,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Equity offering 285.3us-gaap_StockIssuedDuringPeriodValueNewIssues 731.3us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
1.3us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
          709.4us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementClassOfStockAxis
= clf_DepositarySharesMember
(21.9)us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementClassOfStockAxis
= clf_DepositarySharesMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
  284.0us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonStockMember
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
Purchase of subsidiary shares from noncontrolling interest       295.4us-gaap_MinorityInterestDecreaseFromRedemptions
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
(82.7)us-gaap_MinorityInterestDecreaseFromRedemptions
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
             
Undistributed losses to noncontrolling interest to subsidiary 17.0clf_UndistributedEarningsLossesRelatedToNoncontrollingInterests             17.0clf_UndistributedEarningsLossesRelatedToNoncontrollingInterests
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Capital contribution by noncontrolling interest to subsidiary 5.2us-gaap_ProceedsFromMinorityShareholders     0.2us-gaap_ProceedsFromMinorityShareholders
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
(0.6)us-gaap_ProceedsFromMinorityShareholders
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
    5.6us-gaap_ProceedsFromMinorityShareholders
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Stock Issued During Period, Value, Acquisitions (102.1)us-gaap_StockIssuedDuringPeriodValueAcquisitions             (314.8)us-gaap_StockIssuedDuringPeriodValueAcquisitions
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Stock and other incentive plans (in shares)     300,000us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Stock and other incentive plans 14.2us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation     (2.9)us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
  17.1us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
           
Common stock dividends ($0.60 per share) (91.9)us-gaap_DividendsCommonStock       (91.9)us-gaap_DividendsCommonStock
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
             
Preferred stock dividends ($1.66 per depositary share) (48.7)us-gaap_DividendsPreferredStock       (48.7)us-gaap_DividendsPreferredStock
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
             
Preferred Stock, Shares Outstanding   29,300,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
                   
Balance, end of period at Dec. 31, 2013 6,884.3us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest 731.3us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
19.8us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
2,329.5us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
3,407.3us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
(305.5)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
(112.9)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
814.8us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Balance, end of period (in shares) at Dec. 31, 2013 153,126,291us-gaap_CommonStockSharesOutstanding   153,200,000us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]                        
NET INCOME (LOSS) (8,311.6)us-gaap_ProfitLoss       (7,224.2)us-gaap_ProfitLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
    (1,087.4)us-gaap_ProfitLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 7,357.1us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent           (132.9)us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
         
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest               (4.8)us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Other Comprehensive Income (Loss), Net of Tax (137.7)us-gaap_OtherComprehensiveIncomeLossNetOfTax                      
Pension and OPEB liability, net of tax (91.0)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax                      
Unrealized net loss on marketable securities, net of tax (7.2)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax                      
Total comprehensive income (loss) (8,449.3)us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest             (1,092.2)us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Undistributed losses to noncontrolling interest to subsidiary (25.5)clf_UndistributedEarningsLossesRelatedToNoncontrollingInterests             (25.5)clf_UndistributedEarningsLossesRelatedToNoncontrollingInterests
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Capital contribution by noncontrolling interest to subsidiary (0.1)us-gaap_ProceedsFromMinorityShareholders             (0.1)us-gaap_ProceedsFromMinorityShareholders
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Stock and other incentive plans 0.1us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation     (19.7)us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
  19.8us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
           
Common stock dividends ($0.60 per share) (92.5)us-gaap_DividendsCommonStock       (92.5)us-gaap_DividendsCommonStock
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
             
Preferred stock dividends ($1.66 per depositary share) (51.2)us-gaap_DividendsPreferredStock                      
Preferred Stock Dividends (51.3)clf_PreferredStockDividends       (51.3)clf_PreferredStockDividends
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
             
Preferred Stock, Shares Outstanding   29,300,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
                   
Balance, end of period at Dec. 31, 2014 (1,734.3)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest 731.3us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
19.8us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
2,309.8us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AdditionalPaidInCapitalMember
(3,960.7)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember
(285.7)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember
(245.8)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_AccumulatedOtherComprehensiveIncomeMember
(303.0)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_NoncontrollingInterestMember
       
Balance, end of period (in shares) at Dec. 31, 2014 153,246,754us-gaap_CommonStockSharesOutstanding   153,200,000us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Balance, beginning of period at Sep. 30, 2014                        
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]                        
Preferred stock dividends ($1.66 per depositary share) (12.8)us-gaap_DividendsPreferredStock                      
Preferred Stock, Shares Outstanding   29,300,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
                   
Balance, end of period at Dec. 31, 2014 $ (1,734.3)us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest $ 731.3us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= clf_DepositarySharesMember
$ 19.8us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember
                 
Balance, end of period (in shares) at Dec. 31, 2014 153,246,754us-gaap_CommonStockSharesOutstanding   153,200,000us-gaap_CommonStockSharesOutstanding
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember