EMPLOYEE BENEFITS (Schedule of FV of Financial Assets for Pension Plans) (Details) (Pension plan [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
FCX [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 1,300		$ 1,141		$ 1,112
Cash and Receivables In Plan Assets	5		6
Payables In Plan Assets	(12)		(13)
PT Freeport Indonesia [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	130		107		97
Cash and Receivables In Plan Assets	61	[1]	56	[1]
Investments [Member] | FCX [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	1,307		1,148
Investments [Member] | FCX [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	232		207
Investments [Member] | FCX [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	989		856
Investments [Member] | FCX [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	86		85
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Global equity [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	481		408
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Global equity [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Global equity [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	481		408
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Global equity [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. real estate securities [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	61		52
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. real estate securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. real estate securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	61		52
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. real estate securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. small-cap equity [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	52		45
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. small-cap equity [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. small-cap equity [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	52		45
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | U.S. small-cap equity [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Real estate property [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	41		35
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Real estate property [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Real estate property [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Real estate property [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	41		35
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Short-term Investments [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	40		22
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	40		22
Investments [Member] | FCX [Member] | Commingled/collective funds [Member] | Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Government bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	48		50
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Government bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	48		50
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Government bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Government bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Emerging markets equity [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	41		36
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Emerging markets equity [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	41		36
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Emerging markets equity [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Emerging markets equity [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Corporate bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	23		22
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Corporate bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	23		22
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Corporate bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Open-ended mutual funds [Member] | Corporate bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets equity [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	28		24
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets equity [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	28		24
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets equity [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets equity [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Mutual funds [Member] | Foreign bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	54		43
Investments [Member] | FCX [Member] | Mutual funds [Member] | Foreign bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	54		43
Investments [Member] | FCX [Member] | Mutual funds [Member] | Foreign bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Mutual funds [Member] | Foreign bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	37		32
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	37		32
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Mutual funds [Member] | Emerging markets bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Government bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	241		233
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Government bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Government bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	241		233
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Government bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Corporate bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	82		73
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Corporate bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Corporate bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	82		73
Investments [Member] | FCX [Member] | Fixed income securities [Member] | Corporate bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Private equity investments [Member] | Private equity investments [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	45		50
Investments [Member] | FCX [Member] | Private equity investments [Member] | Private equity investments [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Private equity investments [Member] | Private equity investments [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | FCX [Member] | Private equity investments [Member] | Private equity investments [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	45		50
Investments [Member] | FCX [Member] | Other investments [Member] | Other investments [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	33		23
Investments [Member] | FCX [Member] | Other investments [Member] | Other investments [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	1		0
Investments [Member] | FCX [Member] | Other investments [Member] | Other investments [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	32		23
Investments [Member] | FCX [Member] | Other investments [Member] | Other investments [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	69		51
Investments [Member] | PT Freeport Indonesia [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	69		51
Investments [Member] | PT Freeport Indonesia [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member] | Government bonds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	27		22
Investments [Member] | PT Freeport Indonesia [Member] | Government bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	27		22
Investments [Member] | PT Freeport Indonesia [Member] | Government bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member] | Government bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member] | Common stocks [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	32		29
Investments [Member] | PT Freeport Indonesia [Member] | Common stocks [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	32		29
Investments [Member] | PT Freeport Indonesia [Member] | Common stocks [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member] | Common stocks [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Investments [Member] | PT Freeport Indonesia [Member] | Mutual funds [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	10
Investments [Member] | PT Freeport Indonesia [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	10
Investments [Member] | PT Freeport Indonesia [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Investments [Member] | PT Freeport Indonesia [Member] | Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets measurement [Line items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 0

[1] Cash consisted primarily of short-term time deposits.