Business Segments (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011
Revenues:
Unaffiliated customers	$ 4,417		$ 5,195		$ 13,497		$ 16,718
Intersegment	0		0		0		0
Production and delivery	2,592		2,570		7,642		7,504
Depreciation, depletion and amortization	298		257		856		756
Selling, general and administrative expenses	110		102		311		323
Exploration and research expenses	79		78		214		194
Environmental obligations and shutdown costs	(73)		38		18		98
Operating income (loss)	1,411		2,150		4,456		7,843
Interest expense, net	42		78		148		250
Provision for income taxes	215		808		1,128		2,698
Total assets	34,517		31,708		34,517		31,708		32,070
Capital expenditures	971		717		2,518		1,749
Sales from PT Freeport Indonesia to PT Smelting	520		665		1,477		2,000
North America Copper Mines Segment [Member]
Revenues:
Unaffiliated customers	49		122		179		525
Intersegment	1,267		1,297		4,020		3,814
Production and delivery	760		664		2,249		1,923
Depreciation, depletion and amortization	88		67		275		196
Selling, general and administrative expenses	1		1		3		3
Exploration and research expenses	1		3		1		4
Environmental obligations and shutdown costs	0		(14)		42		(11)
Operating income (loss)	466		698		1,629		2,224
Interest expense, net	2		1		4		6
Provision for income taxes	0		0		0		0
Total assets	7,825		6,947		7,825		6,947
Capital expenditures	272		138		569		342
Morenci [Member]
Revenues:
Unaffiliated customers	39		78		157		371
Intersegment	456		450		1,374		1,274
Production and delivery	268		252		803		719
Depreciation, depletion and amortization	31		27		95		85
Selling, general and administrative expenses	0		0		1		1
Exploration and research expenses	1		3		1		4
Environmental obligations and shutdown costs	0		1		0		4
Operating income (loss)	195		245		631		832
Interest expense, net	1		0		1		2
Provision for income taxes	0		0		0		0
Total assets	2,297		1,981		2,297		1,981
Capital expenditures	108		21		204		69
Other North America Copper Mines [Member]
Revenues:
Unaffiliated customers	10		44		22		154
Intersegment	811		847		2,646		2,540
Production and delivery	492		412		1,446		1,204
Depreciation, depletion and amortization	57		40		180		111
Selling, general and administrative expenses	1		1		2		2
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		(15)		42		(15)
Operating income (loss)	271		453		998		1,392
Interest expense, net	1		1		3		4
Provision for income taxes	0		0		0		0
Total assets	5,528		4,966		5,528		4,966
Capital expenditures	164		117		365		273
South America Mines Segment [Member]
Revenues:
Unaffiliated customers	995		966		2,848		3,465
Intersegment	197		87		614		438
Production and delivery	530		478		1,483		1,330
Depreciation, depletion and amortization	74		64		208		187
Selling, general and administrative expenses	2		2		5		5
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	586		509		1,766		2,381
Interest expense, net	0		0		5		1
Provision for income taxes	(16)		202		375		829
Total assets	9,936		8,361		9,936		8,361
Capital expenditures	267		174		659		431
Cerro Verde [Member]
Revenues:
Unaffiliated customers	504		396		1,285		1,662
Intersegment	71		105		349		303
Production and delivery	197		196		575		569
Depreciation, depletion and amortization	39		32		102		102
Selling, general and administrative expenses	1		1		2		3
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	338		272		955		1,291
Interest expense, net	0		0		5		1
Provision for income taxes	(88)	[1]	154		131	[1]	476
Total assets	5,704		4,886		5,704		4,886
Capital expenditures	180		64		365		120
Other South America Mines [Member]
Revenues:
Unaffiliated customers	491		570		1,563		1,803
Intersegment	126		(18)		265		135
Production and delivery	333		282		908		761
Depreciation, depletion and amortization	35		32		106		85
Selling, general and administrative expenses	1		1		3		2
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	248		237		811		1,090
Interest expense, net	0		0		0		0
Provision for income taxes	72		48		244		353
Total assets	4,232		3,475		4,232		3,475
Capital expenditures	87		110		294		311
Indonesia - Grasberg [Member]
Revenues:
Unaffiliated customers	845	[2]	1,275	[2]	2,673	[3]	4,112	[3]
Intersegment	146		87		224		544
Production and delivery	587		503		1,676		1,547
Depreciation, depletion and amortization	54		62		153		179
Selling, general and administrative expenses	31		29		91		100
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	319		768		977		2,830
Interest expense, net	3		7		6		9
Provision for income taxes	111		333		387		1,234
Total assets	6,393		5,437		6,393		5,437
Capital expenditures	237		162		624		463
Africa - Tenke [Member]
Revenues:
Unaffiliated customers	365		275		985		959
Intersegment	2		1		9		4
Production and delivery	172		142		456		422
Depreciation, depletion and amortization	42		32		114		98
Selling, general and administrative expenses	2		1		5		6
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	151		101		419		437
Interest expense, net	0		2		0		5
Provision for income taxes	28		20		79		100
Total assets	4,490		3,791		4,490		3,791
Capital expenditures	131		49		428		89
Molybdenum [Member]
Revenues:
Unaffiliated customers	308		332		982		1,119
Intersegment	0		0		0		0
Production and delivery	273		260		812		786
Depreciation, depletion and amortization	18		14		47		44
Selling, general and administrative expenses	3		3		9		11
Exploration and research expenses	0		1		2		3
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	14		54		112		275
Interest expense, net	0		0		0		0
Provision for income taxes	0		0		0		0
Total assets	2,580		2,342		2,580		2,342
Capital expenditures	44		155		197		317
Rod & Refining [Member]
Revenues:
Unaffiliated customers	1,221		1,389		3,802		4,291
Intersegment	7		7		20		19
Production and delivery	1,222		1,390		3,800		4,292
Depreciation, depletion and amortization	2		2		7		6
Selling, general and administrative expenses	0		0		0		0
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		1
Operating income (loss)	4		4		15		11
Interest expense, net	0		0		0		0
Provision for income taxes	0		0		0		0
Total assets	330		323		330		323
Capital expenditures	2		2		5		7
Atlantic Copper Smelting & Refining [Member]
Revenues:
Unaffiliated customers	633		834		2,023		2,241
Intersegment	5		3		22		11
Production and delivery	624		826		1,988		2,274
Depreciation, depletion and amortization	11		11		31		30
Selling, general and administrative expenses	4		5		14		18
Exploration and research expenses	0		0		0		0
Environmental obligations and shutdown costs	0		0		0		0
Operating income (loss)	(1)		(5)		12		(70)
Interest expense, net	3		4		9		12
Provision for income taxes	0		0		0		0
Total assets	1,192		955		1,192		955
Capital expenditures	4		5		11		29
Corporate, Other & Eliminations [Member]
Revenues:
Unaffiliated customers	1		2		5		6
Intersegment	(1,624)		(1,482)		(4,909)		(4,830)
Production and delivery	(1,576)		(1,693)		(4,822)		(5,070)
Depreciation, depletion and amortization	9		5		21		16
Selling, general and administrative expenses	67		61		184		180
Exploration and research expenses	78		74		211		187
Environmental obligations and shutdown costs	(73)		52		(24)		108
Operating income (loss)	(128)		21		(474)		(245)
Interest expense, net	34		64		124		217
Provision for income taxes	92		253		287		535
Total assets	1,771		3,552		1,771		3,552
Capital expenditures	14		32		25		71
Cerro Verde [Member]
Revenues:
Deferred Foreign Income Tax Expense (Benefit) Associated with Foreign Reinvested Profits	$ (234)

[1] Included a net credit of $234 million for the reversal of a net deferred tax liability (refer to Note 4 for further discussion).

[2] Included PT Freeport Indonesia’s sales to PT Smelting totaling $520 million in third-quarter 2012 and $665 million in third-quarter 2011.

[3] Included PT Freeport Indonesia’s sales to PT Smelting totaling $1.5 billion for the first nine months of 2012 and $2.0 billion for the first nine months of 2011.