Carrying amount of an asset that is legally restricted for purposes of settling an asset retirement obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

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- Details

Name:	us-gaap_EnvironmentalRemediationSiteAxis=fcx_NewMexicoArizonaColoradoandOtherStatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_FinancialGuaranteeMember
Namespace Prefix:
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CONTINGENCIES (Financial Assurances) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Freeport-McMoRan Oil & Gas
Guarantor Obligations [Line Items]
Guarantor obligations, carrying value	$ 545
NEW MEXICO
Guarantor Obligations [Line Items]
Legally restricted funds for asset retirement obligations at New Mexico mines	180	$ 180
New Mexico, Arizona, Colorado and Other States
Guarantor Obligations [Line Items]
Guarantor obligations, carrying value	1,200
New Mexico, Arizona, Colorado and Other States \| Guarantee
Guarantor Obligations [Line Items]
Guarantor obligations, carrying value	$ 703