Financial Instruments (Unaudited) Not Designated as Hedging Instruments (Details)	Jun. 30, 2012 lb
Embedded derivatives in provisional sales contracts - Copper [Member] | Derivatives not designated as hedging instruments [Member]
Derivative [Line Items]
Derivative held (in lbs except gold in oz)	484,000,000
Average contract price	3.62
Average market price	3.48
Maturities through	November 2012
Embedded derivatives in provisional sales contracts - Gold [Member] | Derivatives not designated as hedging instruments [Member]
Derivative [Line Items]
Derivative held (in lbs except gold in oz)	96,000
Average contract price	1,600
Average market price	1,585
Maturities through	September 2012
Embedded derivatives in provisional purchase contracts - Copper [Member] | Derivatives not designated as hedging instruments [Member]
Derivative [Line Items]
Derivative held (in lbs except gold in oz)	282,000,000
Average contract price	3.57
Average market price	3.49
Maturities through	October 2012
Freeport McMoRan Corporation [Member] | Fair Value Hedging [Member] | Commodity Contract [Member] | Derivatives designated as hedging instruments [Member]
Derivative [Line Items]
Derivative held (in lbs except gold in oz)	65,000,000
Average contract price	3.55
Maturities through	December 2013
Atlantic Copper [Member] | Forward Contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative [Line Items]
Derivative held (in lbs except gold in oz)	23,000,000
Average contract price	3.36
Maturities through	August 2012