Financial Instruments (Unaudited) Unsettled Derivatives (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Paid to brokers associated with margin requirements			$ 31
Received from customers associated with margin requirements	1		3
Commodity Contract [Member] | Copper futures and swap contracts [Member] | Derivatives designated as hedging instruments [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset position	11	[1],[2]	3	[1],[2]
Commodity Contract [Member] | Copper futures and swap contracts [Member] | Derivatives designated as hedging instruments [Member] | Accounts payable and accrued liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability position	1	[2],[3]	13	[2],[3]
Commodity Contract [Member] | Embedded derivatives in provisional sales/purchases contracts [Member] | Derivatives not designated as hedging instruments | Net accounts receivable [Member]
Derivatives, Fair Value [Line Items]
Asset position	131	[4]	72	[4]
Commodity Contract [Member] | Embedded derivatives in provisional sales/purchases contracts [Member] | Derivatives not designated as hedging instruments | Net accounts payable [Member]
Derivatives, Fair Value [Line Items]
Liability position	74	[4]	82	[4]
Commodity Contract [Member] | Copper forward contracts [Member] | Derivatives not designated as hedging instruments | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Asset position	1	[1]	2	[1]
Commodity Contract [Member] | Copper forward contracts [Member] | Derivatives not designated as hedging instruments | Accounts payable and accrued liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability position	$ 1	[3]	$ 0	[3]

[1] Amounts recorded in other current assets.

[2] FCX received $1 million from brokers associated with margin requirements (recorded in accounts payable and accrued liabilities) as of September 30, 2012, and FCX paid $31 million for margin requirements (recorded in other current assets) as of December 31, 2011. In addition, FCX held $3 million in margin funding from customers as of December 31, 2011, associated with margin requirements (recorded in accounts payable and accrued liabilities).

[3] Amounts recorded in accounts payable and accrued liabilities.

[4] Amounts recorded either as a net accounts receivable or a net accounts payable.