根据第13或15(d)条提交的季度报告

已终止业务已终止业务（叙述）（详情）

v2.4.1.9
终止经营（叙述性）（详情）（美元）
3个月结束 12个月结束
2015年3月31日
2014年3月31日
2014年12月31日
加拿大实体[成员]      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
已终止经营，已终止经营的税收影响 0美元us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		44300000美元us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		 
企业退出成本 (818700000)us-gaap_BusinessExitCosts1
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		0us-gaap_BusinessExitCosts1
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		 
成本法投资 0us-gaap_CostMethodInvestments
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		   
北美煤炭〔成员〕      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
养老金和其他退休后确定收益计划，负债 330000000年us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_NorthAmericanCoalMember 		   
已终止经营，已终止经营的税收影响 100000年us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_NorthAmericanCoalMember 		7200000年us-gaap_DiscontinuedOperationTaxEffectOfDiscontinuedOperation
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_NorthAmericanCoalMember 		 
有形资产减值费用 (73400000)us-gaap_TangibleAssetImpairmentCharges
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_NorthAmericanCoalMember 		   
亚太铁矿石[成员]|亚太铁矿石[成员]      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
有形资产减值费用     526500000年us-gaap_TangibleAssetImpairmentCharges
/ clf_AssetgroupAxis
= clf_AsiaPacificIronOreMember
/ clf_ReportingUnitAxis
= clf_AsiaPacificIronOreMember
其他流动资产[成员]|加拿大实体[成员]      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
按公允价值在合并财务中确认的贷款、相关利息和应收账款 112100000年clf_LoansAssociatedInterestandAccountsReceivablerecognizedinConsolidatedFinancialsatFairValue
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentAssetsMember
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		   
其他流动负债[成员]| Bloom Lake Group[成员]      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
合并财务中确认的或有负债 166100000年clf_ContingentLiabilitiesrecognizedinConsolidatedFinancials
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_BloomLakeGroupMember 		   
已停止经营的短期负债[成员]|加拿大实体[成员]      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
未提交CCAA备案的布鲁姆湖集团全资子公司负债 51400000年clf_LiabilitiesRecordedforWhollyownedSubsidiariesofBloomLakeGroupthatdidnotfileCCAA
/ us-gaap_BalanceSheetLocationAxis
= clf_ShorttermLiabilitiesofDiscontinuedOperationsMember
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember 		   
已停止经营的长期负债[成员]|加拿大实体[成员]      
各处置集团损益表、资产负债表和其他披露，包括已终止业务[项目]      
未提交CCAA备案的布鲁姆湖集团全资子公司负债 125200000美元clf_LiabilitiesRecordedforWhollyownedSubsidiariesofBloomLakeGroupthatdidnotfileCCAA
/ us-gaap_BalanceSheetLocationAxis
= clf_LongtermLiabilitiesofDiscontinuedOperationsMember
/ us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
= clf_CanadianEntitiesMember