Business Segments (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Dec. 31, 2011
Revenues:
Unaffiliated customers	$ 4,605		$ 5,709
Intersegment	0		0
Production and delivery	2,428		2,377
Depreciation, depletion and amortization	267		232
Selling, general and administrative expenses	104		114
Exploration and research expenses	62		50
Environmental obligations and shutdown costs	10		0
Operating income (loss)	1,734		2,936
Interest expense, net	63		98
Provision for income taxes	491		984
Total assets	32,905		31,008		32,070
Capital expenditures	707		505
Sales from PT Freeport Indonesia to PT Smelting	589		680
Indonesia - Grasberg [Member]
Revenues:
Unaffiliated customers	953	[1]	1,372	[1]
Intersegment	(3)		358
Production and delivery	495		526
Depreciation, depletion and amortization	46		57
Selling, general and administrative expenses	33		43
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	376		1,104
Interest expense, net	0		1
Provision for income taxes	150		496
Total assets	5,613		5,440
Capital expenditures	182		125
Africa - Tenke [Member]
Revenues:
Unaffiliated customers	303		309
Intersegment	2		0
Production and delivery	132		124
Depreciation, depletion and amortization	32		28
Selling, general and administrative expenses	2		2
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	139		155
Interest expense, net	0		2
Provision for income taxes	29		40
Total assets	4,138		3,630
Capital expenditures	127		11
Molybdenum [Member]
Revenues:
Unaffiliated customers	340		374
Intersegment	0		0
Production and delivery	262		240
Depreciation, depletion and amortization	15		14
Selling, general and administrative expenses	3		4
Exploration and research expenses	1		1
Environmental obligations and shutdown costs	0
Operating income (loss)	59		115
Interest expense, net	0		0
Provision for income taxes	0		0
Total assets	2,543		2,068
Capital expenditures	95		71
Rod & Refining [Member]
Revenues:
Unaffiliated customers	1,298		1,481
Intersegment	6		6
Production and delivery	1,297		1,481
Depreciation, depletion and amortization	2		2
Selling, general and administrative expenses	0		0
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	5		4
Interest expense, net	0		0
Provision for income taxes	0		0
Total assets	328		384
Capital expenditures	3		3
Atlantic Copper Smelting & Refining [Member]
Revenues:
Unaffiliated customers	704		756
Intersegment	8		6
Production and delivery	695		763
Depreciation, depletion and amortization	10		10
Selling, general and administrative expenses	5		8
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	2		(19)
Interest expense, net	3		4
Provision for income taxes	0		0
Total assets	1,033		1,437
Capital expenditures	3		8
Corporate, Other & Eliminations [Member]
Revenues:
Unaffiliated customers	2		2
Intersegment	(1,718)		(1,718)
Production and delivery	(1,623)		(1,756)
Depreciation, depletion and amortization	7		6
Selling, general and administrative expenses	58		54
Exploration and research expenses	61		49
Environmental obligations and shutdown costs	10
Operating income (loss)	(229)		(69)
Interest expense, net	54		89
Provision for income taxes	72		142
Total assets	2,422		3,435
Capital expenditures	2		28
North America Copper Mines Segment [Member] | Morenci [Member]
Revenues:
Unaffiliated customers	13		136
Intersegment	513		386
Production and delivery	256		210
Depreciation, depletion and amortization	31		28
Selling, general and administrative expenses	0		0
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	239		284
Interest expense, net	0		1
Provision for income taxes	0		0
Total assets	2,146		1,991
Capital expenditures	44		29
North America Copper Mines Segment [Member] | Other North America Copper Mines [Member]
Revenues:
Unaffiliated customers	17		16
Intersegment	913		823
Production and delivery	451		378
Depreciation, depletion and amortization	62		30
Selling, general and administrative expenses	1		1
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	416		430
Interest expense, net	1		1
Provision for income taxes	0		0
Total assets	5,255		4,623
Capital expenditures	99		90
North America Copper Mines Segment [Member] | Total North America Copper Mines [Member]
Revenues:
Unaffiliated customers	30		152
Intersegment	1,426		1,209
Production and delivery	707		588
Depreciation, depletion and amortization	93		58
Selling, general and administrative expenses	1		1
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	655		714
Interest expense, net	1		2
Provision for income taxes	0		0
Total assets	7,401		6,614
Capital expenditures	143		119
South America Mines Segment [Member] | Cerro Verde [Member]
Revenues:
Unaffiliated customers	449		668
Intersegment	127		60
Production and delivery	193		175
Depreciation, depletion and amortization	30		34
Selling, general and administrative expenses	1		1
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	352		518
Interest expense, net	5		0
Provision for income taxes	123		163
Total assets	5,300		4,573
Capital expenditures	69		24
South America Mines Segment [Member] | Other South America Mines [Member]
Revenues:
Unaffiliated customers	526		595
Intersegment	152		79
Production and delivery	270		236
Depreciation, depletion and amortization	32		23
Selling, general and administrative expenses	1		1
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	375		414
Interest expense, net	0		0
Provision for income taxes	117		143
Total assets	4,127		3,427
Capital expenditures	83		116
South America Mines Segment [Member] | Total South America Mines [Member]
Revenues:
Unaffiliated customers	975		1,263
Intersegment	279		139
Production and delivery	463		411
Depreciation, depletion and amortization	62		57
Selling, general and administrative expenses	2		2
Exploration and research expenses	0		0
Environmental obligations and shutdown costs	0
Operating income (loss)	727		932
Interest expense, net	5		0
Provision for income taxes	240		306
Total assets	9,427		8,000
Capital expenditures	$ 152		$ 140

[1] Includes PT Freeport Indonesia’s sales to PT Smelting totaling $589 million in first-quarter 2012 and $680 million in first-quarter 2011.