XML 50 R82.htm IDEA: XBRL DOCUMENT
v3.20.1

FAIR VALUE MEASUREMENTS (Fair Value of Assets and Liabilities) (Details) - USD ($) $ in Millions | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Assets, Fair Value Disclosure | $ 21.2 | $ 233.4
Liabilities, Fair Value Disclosure | 32.4 | 4.3
Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Assets, Fair Value Disclosure | 0.0 | 0.0
Liabilities, Fair Value Disclosure | 0.0 | 0.0
Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Assets, Fair Value Disclosure | 1.6 | 187.6
Liabilities, Fair Value Disclosure | 32.4 | 3.2
Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Assets, Fair Value Disclosure | 19.6 | 45.8
Liabilities, Fair Value Disclosure | 0.0 | 1.1
Cash and Cash Equivalents [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Cash equivalents |  | 187.6
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Cash equivalents |  | 0.0
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Cash equivalents |  | 187.6
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Cash equivalents |  | 0.0
Commodity Contract [Member] | Other Current Assets [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 1.6 |
Commodity Contract [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 0.0 |
Commodity Contract [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 1.6 |
Commodity Contract [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 0.0 |
Commodity Contract [Member] | Other Current Liabilities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 26.5 | 3.2
Commodity Contract [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 0.0 | 0.0
Commodity Contract [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 26.5 | 3.2
Commodity Contract [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 0.0 | 0.0
Commodity Contract [Member] | Other Noncurrent Liabilities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 3.4 |
Commodity Contract [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 3.4 |
Foreign Exchange Contract [Member] | Other Current Liabilities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 1.6 |
Foreign Exchange Contract [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 1.6 |
Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 0.9 |
Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability | 0.9 |
Customer Supply Agreement [Member] | Other Current Assets [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 19.0 | 44.5
Customer Supply Agreement [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset |  | 0.0
Customer Supply Agreement [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 19.0 | 44.5
Provisional Pricing Arrangements [Member] | Other Current Assets [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | 0.6 | 1.3
Provisional Pricing Arrangements [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset |  | 0.0
Provisional Pricing Arrangements [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset |  | 0.0
Provisional Pricing Arrangements [Member] | Other Current Assets [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative Asset | $ 0.6 | 1.3
Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability |  | 1.1
Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability |  | 0.0
Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability |  | 0.0
Provisional Pricing Arrangements [Member] | Other Current Liabilities [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liability |  | $ 1.1

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities. + References No definition available. + Details
Name: | us-gaap_FinancialLiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=clf_CustomerSupplyAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=clf_ProvisionalPricingArrangementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |