SUPPLEMENTARY OIL AND GAS INFORMATION (UNAUDITED) (Schedule of Costs Incurred) (Details) (USD $)	7 Months Ended		12 Months Ended
	Dec. 31, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Jun. 30, 2014
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Liabilities assumed in the acquisitions of PXP and MMR			$ 0	[1]	$ 1,028,000,000	[1]	$ 0	[1]
Property acquisition costs:
Proved properties	12,205,000,000	[2],[3]	463,000,000
Unproved properties	11,259,000,000	[3],[4]	1,460,000,000
Exploration costs	502,000,000	[3]	1,482,000,000
Development costs	854,000,000	[3]	1,270,000,000
Total	24,820,000,000	[3]	4,675,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Oil and Gas Properties, Subject to Depletion	12,200,000,000				12,200,000,000				12,198,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Oil and Gas Properties, Not Subject to Depletion	11,100,000,000				11,100,000,000				11,112,000,000
Oil and Gas Operations Segment [Member]
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Capitalized Costs, Asset Retirement Costs	1,100,000,000		(27,000,000)		1,100,000,000
General and Administrative Costs Capitalized			143,000,000		67,000,000
Interest Costs Capitalized			$ 88,000,000		$ 69,000,000

[1] The fair value of AROs assumed in the acquisitions of PXP and MMR ($741 million and $287 million, respectively) were estimated based on projected cash flows, an estimated long-term annual inflation rate of 2.5 percent, and discount rates based on FCX's estimated credit-adjusted, risk-free interest rates ranging from 1.3 percent to 6.3 percent.

[2] Includes $12.2 billion from the acquisitions of PXP and MMR.

[3] Includes the results of FM O&G beginning June 1, 2013.

[4] Includes $11.1 billion from the acquisitions of PXP and MMR.