The average market price for a group of price risk forward or futures contracts, such as gas futures contracts.

No definition available.

Name:	fcx_DerivativeAverageMarketPrice
Namespace Prefix:	fcx_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

+ References

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The average forward price on the group of price risk forward or futures contracts, such as gas futures contracts.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeAverageForwardPrice
Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

+ Details

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

- Definition

Nominal mass used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeNonmonetaryNotionalAmountMass
Namespace Prefix:	us-gaap_
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Details

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

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EmbeddedDerivativeFinancialInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesInventoryAxis=fcx_CopperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesInventoryAxis=fcx_GoldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financial Instruments (Unrealized gains losses) (Details) oz in Thousands, lb in Millions, $ in Millions		3 Months Ended		12 Months Ended
	Mar. 31, 2017 lb oz $ / lb $ / lb $ / oz	Mar. 31, 2017 USD ($) $ / lb $ / lb $ / oz	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Commodity Contract [Member]
Unrealized gains (losses):
Derivative financial instruments \| $		$ (2)	$ 7
Hedged item – firm sales commitments \| $		2	(7)
Realized gains (losses):
Matured derivative financial instruments \| $		$ 8	(4)
Commodity Contract [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	48
Derivative, Average Forward Price	2.56	2.56
Embedded Derivative Financial Instruments [Member] \| Derivatives Not Designated as Hedging Instruments [Member] \| Amounts recorded in Sales [Member]
Realized gains (losses):
Matured derivative financial instruments \| $		$ 126	$ 72
Copper Forward Contracts [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	8
Derivative, Average Forward Price	2.64	2.64
Copper Forward Contracts [Member] \| Derivatives Not Designated as Hedging Instruments [Member] \| Amounts recorded in Cost of Sales
Realized gains (losses):
Matured derivative financial instruments \| $		$ (1)		$ 7
Copper \| Short [Member] \| Embedded Derivative Financial Instruments [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	443
Derivative, Average Forward Price	2.61	2.61
Realized gains (losses):
Derivative Average Market Price	2.64	2.64
Copper \| Long [Member] \| Embedded Derivative Financial Instruments [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	109
Derivative, Average Forward Price	2.64	2.64
Realized gains (losses):
Derivative Average Market Price	2.65	2.65
Gold \| Short [Member] \| Embedded Derivative Financial Instruments [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	50
Derivative, Average Forward Price \| $ / oz	1,222	1,222
Realized gains (losses):
Derivative Average Market Price \| $ / oz	1,246	1,246