Unamortized debt issuance costs, net and fair value adjustments.

No definition available.

Name:	fcx_DebtIssuanceCostsandFairValueAdjustments
Namespace Prefix:	fcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Gross redemption value of debt extinguished.

+ References

No definition available.

+ Details

Name:	fcx_ExtinguishmentOfDebtRedemptionValue
Namespace Prefix:	fcx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Balance Type:	credit
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DEBT - Schedule of Senior Notes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Debt Instruments [Line Items]
Gain (Loss) on Extinguishment of Debt	$ 0	$ (101)	$ (27)
4.00% Senior Notes Due 2021
Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				4.00%
Senior Notes [Member]
Debt Instruments [Line Items]
Debt Instrument, Face Amount		2,598	2,145
DebtIssuanceCostsandFairValueAdjustments		(12)	30
Extinguishment of Debt, Amount		2,586	2,175
Extinguishment Of Debt, Redemption Value		2,686	2,201
Gain (Loss) on Extinguishment of Debt		100	26
Senior Notes [Member] \| 3.100% Senior Notes due March 2020
Debt Instruments [Line Items]
Debt Instrument, Face Amount			1,000
DebtIssuanceCostsandFairValueAdjustments			(2)
Extinguishment of Debt, Amount			998
Extinguishment Of Debt, Redemption Value			1,003
Gain (Loss) on Extinguishment of Debt			5
Debt Instrument, Interest Rate, Stated Percentage	3.10%
Senior Notes [Member] \| 3.55% Senior Notes Due 2022
Debt Instruments [Line Items]
Debt Instrument, Face Amount	$ 524	1,356	12
DebtIssuanceCostsandFairValueAdjustments	0	(6)	0
Extinguishment of Debt, Amount	524	1,350	12
Extinguishment Of Debt, Redemption Value	524	1,391	12
Gain (Loss) on Extinguishment of Debt	$ 0	41	0
Debt Instrument, Interest Rate, Stated Percentage	3.55%
Senior Notes [Member] \| 4.00% Senior Notes Due 2021
Debt Instruments [Line Items]
Debt Instrument, Face Amount		195	405
DebtIssuanceCostsandFairValueAdjustments		(1)	(2)
Extinguishment of Debt, Amount		194	403
Extinguishment Of Debt, Redemption Value		205	418
Gain (Loss) on Extinguishment of Debt		11	15
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Senior Notes [Member] \| 3.875% Senior Notes due March 2023
Debt Instruments [Line Items]
Debt Instrument, Face Amount		927
DebtIssuanceCostsandFairValueAdjustments		(4)
Extinguishment of Debt, Amount		923
Extinguishment Of Debt, Redemption Value		964
Gain (Loss) on Extinguishment of Debt		$ 41
Debt Instrument, Interest Rate, Stated Percentage	3.875%
Senior Notes [Member] \| 6.875% Senior Notes due 2023
Debt Instruments [Line Items]
Debt Instrument, Face Amount			728
DebtIssuanceCostsandFairValueAdjustments			34
Extinguishment of Debt, Amount			762
Extinguishment Of Debt, Redemption Value			768
Gain (Loss) on Extinguishment of Debt			$ 6
Debt Instrument, Interest Rate, Stated Percentage	6.875%	6.875%
Senior Notes [Member] \| 4.55% Senior Notes due 2024
Debt Instruments [Line Items]
Debt Instrument, Face Amount		$ 120
DebtIssuanceCostsandFairValueAdjustments		(1)
Extinguishment of Debt, Amount		119
Extinguishment Of Debt, Redemption Value		126
Gain (Loss) on Extinguishment of Debt		$ 7
Senior Notes [Member] \| 6.125% Senior Notes due 2019 [Member]
Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.125%
Senior Notes [Member] \| 6.5% Senior Notes due 2020 [Member]
Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%	6.50%
Senior Notes [Member] \| 6.625% Senior Notes due 2021 [Member]
Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%	6.625%
Senior Notes [Member] \| 6.75% Senior Notes due 2022 [Member]
Debt Instruments [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.75%	6.75%