OTHER LIABILITIES, INCLUDING EMPLOYEE BENEFITS (Schedule of Disclosures) (Details) In Millions, unless otherwise specified	12 Months Ended										12 Months Ended								12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 Pension plan [Member] USD ($)	Dec. 31, 2013 Pension plan [Member] USD ($)	Dec. 31, 2012 Pension plan [Member] USD ($)	Dec. 31, 2014 Postretirement Medical And Life Insurance [Member] USD ($)	Dec. 31, 2013 Postretirement Medical And Life Insurance [Member] USD ($)	Dec. 31, 2014 Other Benefits [Member] USD ($)	Dec. 31, 2013 Other Benefits [Member] USD ($)	Dec. 31, 2014 Minimum [Member] Pension plan [Member]	Dec. 31, 2014 PT Freeport Indonesia [Member] Pension plan [Member] USD ($)		Dec. 31, 2013 PT Freeport Indonesia [Member] Pension plan [Member] USD ($)		Dec. 31, 2012 PT Freeport Indonesia [Member] Pension plan [Member] USD ($)	Dec. 31, 2014 PT Freeport Indonesia [Member] Pension plan [Member] IDR	Dec. 31, 2013 PT Freeport Indonesia [Member] Pension plan [Member] IDR	Dec. 31, 2014 FCX [Member] Pension plan [Member] USD ($)		Dec. 31, 2013 FCX [Member] Pension plan [Member] USD ($)		Dec. 31, 2012 FCX [Member] Pension plan [Member] USD ($)
Schedule of disclosures of defined benefit plans [Line Items]
Exchange Rate Of Rupiah To Dollars																	12,378	12,128
Defined benefit plan, expected return on plan assets	7.25%											7.75%
Change in benefit obligation [Roll Forward]
Benefit obligation at beginning of year												$ 259		$ 240					$ 1,871		$ 1,954
Service cost												22		20		17			30		30		27
Interest cost												23		14		14			92		77		79
Actuarial losses (gains)												30		13					278		(103)
Plan Amendment												0		33					0		0
Foreign exchange losses (gains)												(7)		(53)					(2)		1
Benefits paid												(9)		(8)					(90)		(88)
Benefits obligation at end of year												318		259		240			2,179		1,871		1,954
Change in plan assets [Roll Forward]
Fair value of plan assets at beginning of year												124		130					1,350		1,300
Actual return on plan assets												20		(3)					151		112
Employer contributions												55	[1]	35	[1]				6	[1]	26	[1]
Foreign exchange gains (losses)												(5)		(30)					(1)		0
Benefits paid												(9)		(8)					(90)		(88)
Fair value of plan assets at end of year												185		124		130			1,416		1,350		1,300
Funded status at end of year												(133)		(135)					(763)		(521)
Accumulated benefit obligation												168		141					2,048		1,742
Weighted-average assumptions used to determine benefit obligations [Abstract]
Discount rate							3.60%	4.30%				8.25%		9.00%					4.10%		5.00%
Rate of compensation increase												9.00%		9.00%					3.25%		3.75%
Balance sheet classification of funded status: [Abstract]
Other assets												0		0					8		8
Accounts payable and accrued liabilities							(17)	(19)	(6)	(9)		0		0					(4)		(4)
Other liabilities							(162)	(163)	(38)	(75)		(133)		(135)					(767)		(525)
Total												(133)		(135)					(763)		(521)
Estimated future employer contributions in next fiscal year												20							98
Weighted-average assumptions used to determine benefit obligations [Abstract]
Discount rate				4.30%	3.50%	4.20%						9.00%		6.25%		7.00%			5.00%	[2]	4.10%	[2]	4.60%	[2]
Expected return on plan assets												7.75%		7.50%		9.25%			7.50%	[2]	7.50%	[2]	7.50%	[2]
Rate of compensation increase												9.00%		8.00%		8.00%			3.75%	[2]	3.75%	[2]	3.75%	[2]
Threshold for Amortization of Actuarial Gains (Losses), Percent											10.00%
Components of net periodic benefit (income) cost and other amounts recognized in other comprehensive income [Abstract]
Service cost												22		20		17			30		30		27
Interest cost												23		14		14			92		77		79
Expected return on plan assets												(10)		(10)		(9)			(98)		(95)		(86)
Amortization of prior service cost												3		0		1			(1)		0		(1)
Amortization of net actuarial losses												8		8		7			28		38		33
Net periodic benefit cost												46		32		30			51		50		52
Amounts recognized in other comprehensive loss (income) [Abstract]
Prior service (credit) cost		33		28	32
Prior service (credit) cost, net of tax	0	21	0	15	17
Actuarial net loss (gain)				749	542
Actuarial net loss (gain), net of tax	161	(73)	69	456	326
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax				777	574
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax				471	343
Estimated actuarial net loss (gain) in next fiscal year				52
Estimated actuarial net loss (gain) in next fiscal year, net of tax				32
Assumed health care cost trend rates abstract
Health care cost trend rates for the next fiscal year				7.50%
Duration over which health care costs reach ultimate trend rate	15 years
Ultimate health care cost trend rate				4.25%
Expected cash flows for benefit plans [Abstract]
2015							17					20	[3]						97
2016							16					9	[3]						155
2017							15					16	[3]						103
2018							14					20	[3]						107
2019							15					24	[3]						110
2020-2024							64					172	[3]						603
Estimated Other Comprehensive Income, Defined Benefit Plans, Prior Service Cost Arising During Period, Before Tax				$ 7	$ 9	$ 10

[1] Employer contributions for 2015 are expected to approximate $98 million for the FCX plans and $20 million for the PT-FI plan (based on a December 31, 2014, exchange rate of 12,378 Indonesian rupiah to one U.S. dollar).

[2] The assumptions shown relate only to the FMC plans.

[3] Based on a December 31, 2014, exchange rate of 12,378 Indonesian rupiah to one U.S. dollar.