Financial Instruments (Unaudited) Unsettled Derivatives (Details) - USD ($) $ in Millions		Sep. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset		$ 116	$ 330
Derivative Liability		74	99
Paid to brokers associated with margin requirements		16	10
Trade Accounts Receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset		6	5
Derivative Liability		50	56
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset		101	316
Derivative Liability		0	0
Accounts Payable and Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset		9	9
Derivative Liability		24	43
Commodity Contract [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position		119	331
Liability position		77	100
Derivative Asset, Fair Value, Gross Liability		3	1
Derivative Liability, Fair Value, Gross Asset		3	1
Derivative Asset		116	330
Derivative Liability		74	99
Commodity Contract [Member] | Copper Derivatives [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position		1	0
Liability position		8	7
Derivative Asset, Fair Value, Gross Liability		1	0
Derivative Liability, Fair Value, Gross Asset		1	0
Derivative Asset		0	0
Derivative Liability		7	7
Commodity Contract [Member] | Copper futures and swap contracts [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	[1]	1	0
Liability position	[1]	8	7
Commodity Contract [Member] | Embedded derivatives in provisional sales/purchases contracts [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position		17	15
Liability position		69	93
Derivative Asset, Fair Value, Gross Liability		2	1
Derivative Liability, Fair Value, Gross Asset		2	1
Derivative Asset		15	14
Derivative Liability		67	92
Commodity Contract [Member] | Crude Oil and Natural Gas Derivatives [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position		101	316
Liability position		0	0
Derivative Asset, Fair Value, Gross Liability		0	0
Derivative Liability, Fair Value, Gross Asset		0	0
Derivative Asset		101	316
Derivative Liability		0	0
Commodity Contract [Member] | Crude Oil Options [Member] | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Asset position	[2]	101	316
Deferred Option Premiums and Accrued Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability		$ 53	$ 210

[1] FCX paid $16 million to brokers at September 30, 2015, and $10 million at December 31, 2014, for margin requirements (recorded in other current assets).

[2] Amounts are net of $53 million at September 30, 2015, and $210 million at December 31, 2014, for deferred premiums and accrued interest.