GUARANTOR FINANCIAL STATEMENTS (Condensed Consolidated Cash Flow Statement) (Details) - USD ($) $ in Millions	3 Months Ended											7 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014	[1],[2]	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Cash flow from operating activities:
Net (loss) income	$ (4,094)	$ (3,790)	$ (1,799)	$ (2,406)	$ (2,735)	[1],[2]	$ 704	[1],[2]	$ 660		$ 626		$ (12,089)	$ (745)	[1],[2]	$ 3,441
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization													3,497	3,863		2,797
Impairment of oil and gas properties	3,700	3,700	2,700	3,100	3,400		$ 308					$ 0	13,144	3,737		0
Impairment of oil and gas properties and goodwill														5,454
Copper and molybdenum inventory adjustments	184	$ 91	$ 59	4									338	6		3
Other asset impairments, inventory write-downs, restructuring and other													256
Net (gains) losses on crude oil and natural gas derivative contracts													(87)	(504)		334
Gain on investment in MMR													0	0		(128)
Equity in (earnings) losses of consolidated subsidiaries													3	(3)		0
Other, net													(2,215)	(1,802)		72
Increase (decrease) in working capital and changes in other tax payment, excluding amounts from the acquisitions													373	(632)		(377)
Net cash provided by operating activities													3,220	5,631		6,139
Cash flow from investing activities:
Capital expenditures													(6,353)	(7,215)		(5,286)
Acquisitions, net of cash acquired														(1,426)		(5,441)
Intercompany loans													0	0		0
Dividends from (investments in) consolidated subsidiaries													(2)	0		0
Net proceeds from sale of Candelaria and Ojos del Salado													0	1,709		0
Net proceeds from sale of Eagle Ford shale assets													0	2,910		0
Dividends from (investments in) consolidated subsidiaries													(109)	(221)		181
Net cash used in investing activities													(6,246)	(3,801)		(10,908)
Cash flow from financing activities:
Proceeds from debt													8,272	8,710		11,501
Repayments of debt and redemption of MMR preferred stock													(6,677)	(10,306)		5,704
Intercompany loans													0	0		0
Net proceeds from sale of common stock													1,936	0		0
Cash dividends and distributions paid, and contributions received													(725)	(1,729)		(2,537)
Other, net													(20)	(26)		(211)
Net cash provided by (used in) financing activities													2,786	(3,351)		3,049
Net decrease in cash and cash equivalents													(240)	(1,521)		(1,720)
Cash and cash equivalents at beginning of year				464							1,985		464	1,985		3,705
Cash and cash equivalents at end of year	224				464							1,985	224	464		1,985
FCX Issuer [Member]
Cash flow from operating activities:
Net (loss) income													(12,236)	(1,308)		2,658
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization													5	4		4
Impairment of oil and gas properties													0
Impairment of oil and gas properties and goodwill														0
Copper and molybdenum inventory adjustments													0
Other asset impairments, inventory write-downs, restructuring and other													0
Net (gains) losses on crude oil and natural gas derivative contracts													0	0		0
Gain on investment in MMR																(128)
Equity in (earnings) losses of consolidated subsidiaries													8,685	1,007		(2,886)
Other, net													(2,127)	(882)		8
Increase (decrease) in working capital and changes in other tax payment, excluding amounts from the acquisitions													5,506	723		272
Net cash provided by operating activities													(167)	(456)		(72)
Cash flow from investing activities:
Capital expenditures													(7)	0		0
Acquisitions, net of cash acquired														0		(5,437)
Intercompany loans													(1,812)	(1,328)		834
Dividends from (investments in) consolidated subsidiaries													852	1,221		629
Net proceeds from sale of Candelaria and Ojos del Salado														0
Net proceeds from sale of Eagle Ford shale assets														0
Dividends from (investments in) consolidated subsidiaries													21	0		(15)
Net cash used in investing activities													(988)	(107)		(3,959)
Cash flow from financing activities:
Proceeds from debt													4,503	7,464		11,260
Repayments of debt and redemption of MMR preferred stock													(4,660)	(5,575)		4,737
Intercompany loans													0	0		0
Net proceeds from sale of common stock													1,936
Cash dividends and distributions paid, and contributions received													(605)	(1,305)		(2,281)
Other, net													(19)	(21)		(211)
Net cash provided by (used in) financing activities													1,155	563		4,031
Net decrease in cash and cash equivalents													0	0		0
Cash and cash equivalents at beginning of year				0							0		0	0		0
Cash and cash equivalents at end of year	0				0							0	0	0		0
FM O&G LLC Guarantor [Member]
Cash flow from operating activities:
Net (loss) income													(12,802)	(4,348)		281
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization													370	806		616
Impairment of oil and gas properties													4,220
Impairment of oil and gas properties and goodwill														1,922
Copper and molybdenum inventory adjustments													0
Other asset impairments, inventory write-downs, restructuring and other													11
Net (gains) losses on crude oil and natural gas derivative contracts													(87)	(504)		334
Gain on investment in MMR																0
Equity in (earnings) losses of consolidated subsidiaries													9,976	3,429		(281)
Other, net													2	(113)		(14)
Increase (decrease) in working capital and changes in other tax payment, excluding amounts from the acquisitions													(1,428)	(1,750)		735
Net cash provided by operating activities													262	(558)		1,671
Cash flow from investing activities:
Capital expenditures													(847)	(2,143)		(894)
Acquisitions, net of cash acquired														0		0
Intercompany loans													(1,310)	704		0
Dividends from (investments in) consolidated subsidiaries													(71)	(130)		0
Net proceeds from sale of Candelaria and Ojos del Salado														0
Net proceeds from sale of Eagle Ford shale assets														2,910
Dividends from (investments in) consolidated subsidiaries													2	(41)		(30)
Net cash used in investing activities													(2,230)	1,382		(864)
Cash flow from financing activities:
Proceeds from debt													0	0		0
Repayments of debt and redemption of MMR preferred stock													0	(3,994)		416
Intercompany loans													2,038	810		(391)
Net proceeds from sale of common stock													0
Cash dividends and distributions paid, and contributions received													0	2,364		0
Other, net													(71)	(3)		0
Net cash provided by (used in) financing activities													1,967	(823)		(807)
Net decrease in cash and cash equivalents													(1)	1		0
Cash and cash equivalents at beginning of year				1							0		1	0		0
Cash and cash equivalents at end of year	0				1							0	0	1		0
Non-Guarantor Subsidiaries [Member]
Cash flow from operating activities:
Net (loss) income													(18,562)	(4,147)		3,934
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization													3,195	3,077		2,177
Impairment of oil and gas properties													8,862
Impairment of oil and gas properties and goodwill														3,486
Copper and molybdenum inventory adjustments													338
Other asset impairments, inventory write-downs, restructuring and other													245
Net (gains) losses on crude oil and natural gas derivative contracts													0	0		0
Gain on investment in MMR																0
Equity in (earnings) losses of consolidated subsidiaries													12,838	4,633		(265)
Other, net													(90)	(807)		78
Increase (decrease) in working capital and changes in other tax payment, excluding amounts from the acquisitions													(3,714)	395		(1,384)
Net cash provided by operating activities													3,112	6,637		4,540
Cash flow from investing activities:
Capital expenditures													(5,486)	(5,072)		(4,392)
Acquisitions, net of cash acquired														(1,426)		(4)
Intercompany loans													0	0		(162)
Dividends from (investments in) consolidated subsidiaries													130	(2,408)		0
Net proceeds from sale of Candelaria and Ojos del Salado														1,709
Net proceeds from sale of Eagle Ford shale assets														0
Dividends from (investments in) consolidated subsidiaries													(111)	(180)		226
Net cash used in investing activities													(5,245)	(7,017)		(4,784)
Cash flow from financing activities:
Proceeds from debt													3,769	1,246		241
Repayments of debt and redemption of MMR preferred stock													(2,017)	(737)		551
Intercompany loans													1,084	(186)		(281)
Net proceeds from sale of common stock													0
Cash dividends and distributions paid, and contributions received													(924)	(1,463)		(885)
Other, net													(18)	(2)		0
Net cash provided by (used in) financing activities													1,894	(1,142)		(1,476)
Net decrease in cash and cash equivalents													(239)	(1,522)		(1,720)
Cash and cash equivalents at beginning of year				463							1,985		463	1,985		3,705
Cash and cash equivalents at end of year	224				463							1,985	224	463		1,985
Eliminations [Member]
Cash flow from operating activities:
Net (loss) income													31,511	9,058		(3,432)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization													(73)	(24)		0
Impairment of oil and gas properties													62
Impairment of oil and gas properties and goodwill														46
Copper and molybdenum inventory adjustments													0
Other asset impairments, inventory write-downs, restructuring and other													0
Net (gains) losses on crude oil and natural gas derivative contracts													0	0		0
Gain on investment in MMR																0
Equity in (earnings) losses of consolidated subsidiaries													(31,496)	(9,072)		3,432
Other, net													0	0		0
Increase (decrease) in working capital and changes in other tax payment, excluding amounts from the acquisitions													9	0		0
Net cash provided by operating activities													13	8		0
Cash flow from investing activities:
Capital expenditures													(13)	0		0
Acquisitions, net of cash acquired														0		0
Intercompany loans													3,122	624		(672)
Dividends from (investments in) consolidated subsidiaries													(913)	1,317		(629)
Net proceeds from sale of Candelaria and Ojos del Salado														0
Net proceeds from sale of Eagle Ford shale assets														0
Dividends from (investments in) consolidated subsidiaries													(21)	0		0
Net cash used in investing activities													2,217	1,941		(1,301)
Cash flow from financing activities:
Proceeds from debt													0	0		0
Repayments of debt and redemption of MMR preferred stock													0	0		0
Intercompany loans													(3,122)	(624)		672
Net proceeds from sale of common stock													0
Cash dividends and distributions paid, and contributions received													804	(1,325)		629
Other, net													88	0		0
Net cash provided by (used in) financing activities													(2,230)	(1,949)		1,301
Net decrease in cash and cash equivalents													0	0		0
Cash and cash equivalents at beginning of year				$ 0							$ 0		0	0		0
Cash and cash equivalents at end of year	$ 0				$ 0							$ 0	$ 0	$ 0		$ 0

[1] Includes net gains (losses) on early extinguishment of debt totaling $4 million in the second quarter, $17 million ($0.02 per share) in the third quarter, $(18) million ($(0.02) per share) in the fourth quarter and $3 million for the year. Refer to Note 8 for further discussion.

[2] Includes tax charges of $57 million ($0.06 per share) in the second quarter, $5 million in the third quarter, $22 million ($0.02 per share) in the fourth quarter and $84 million ($0.08 per share) for the year associated with deferred taxes recorded in connection with the allocation of goodwill to the sale of the Eagle Ford shale assets. Additionally, includes net tax charges (benefit) of $54 million ($7 million attributable to noncontrolling interests and $47 million to net income attributable to common stockholders or $0.04 per share) in the third quarter, $(17) million ($11 million attributable to noncontrolling interests and $(28) million to net loss attributable to common stockholders or $(0.03) per share) in the fourth quarter and $37 million ($18 million attributable to noncontrolling interests and $19 million to net loss attributable to common stockholders or $0.02 per share) for the year associated with changes in Chilean tax rules, U.S. federal income tax law and Peruvian tax rules, partially offset by a tax benefit related to changes in U.S. state income tax filing positions.