Financial Instruments (Unaudited) Unsettled Derivatives (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Paid to brokers associated with margin requirements	$ 3		$ 7
Derivative Asset	53		33
Derivative Liability	208		20
Trade Accounts Receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	46		24
Derivative Liability	1		9
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	6		5
Derivative Liability	0		0
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0		0
Derivative Liability	0		0
Accounts Payable and Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	1		4
Derivative Liability	116		11
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	0		0
Derivative Liability	91		0
Commodity Contract [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	78		41
Liability position	233		28
Derivative Asset, Fair Value, Gross Liability	25		8
Derivative Liability, Fair Value, Gross Asset	25		8
Derivative Asset	53		33
Derivative Liability	208		20
Commodity Contract [Member] | Copper Derivatives [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	3		5
Liability position	2		1
Derivative Asset, Fair Value, Gross Liability	1		0
Derivative Liability, Fair Value, Gross Asset	1		0
Derivative Asset	2		5
Derivative Liability	1		1
Commodity Contract [Member] | Copper futures and swap contracts [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	3	[1]	5	[1]
Liability position	1	[1]	1	[1]
Commodity Contract [Member] | Copper forward contracts [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Liability position	1		0
Commodity Contract [Member] | Embedded derivatives in provisional sales/purchases contracts [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	51		36
Liability position	13		27
Derivative Asset, Fair Value, Gross Liability	4		8
Derivative Liability, Fair Value, Gross Asset	4		8
Derivative Asset	47		28
Derivative Liability	9		19
Commodity Contract [Member] | Crude Oil and Natural Gas Derivatives [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	24		0
Liability position	218		0
Derivative Asset, Fair Value, Gross Liability	20		0
Derivative Liability, Fair Value, Gross Asset	20		0
Derivative Asset	4		0
Derivative Liability	198		0
Commodity Contract [Member] | Crude Oil and Natural Gas Swaps [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	24		0
Crude Oil Options [Member] | Embedded derivatives in provisional sales/purchases contracts [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Liability position	218		0
Deferred Option Premiums and Accrued Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	$ 461

[1] FCX paid $3 million to brokers at September 30, 2013, and $7 million at December 31, 2012, for margin requirements (recorded in other current assets).