Guarantor Financial Statements (Unaudited) Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions		Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
ASSETS
Current assets		$ 8,155	$ 9,045
Property, plant, equipment and mining development costs, net		27,355	26,220
Oil and gas properties, net - full cost method
Subject to amortization, less accumulated amortization		3,002	9,187
Not subject to amortization		7,568	10,087
Investments in consolidated subsidiaries		0	0
Other assets		4,303	4,135
Total assets		50,383	58,674	$ 63,875
LIABILITIES AND EQUITY
Current liabilities		4,827	5,172
Long-term debt, less current portion		19,792	18,371
Deferred income taxes		4,363	6,398
Environmental and asset retirement obligations, less current portion		3,708	3,647
Other liabilities		1,727	1,861
Total liabilities		34,417	35,449
Redeemable noncontrolling interest		761	751
Equity:
Stockholders' equity		10,946	18,287
Noncontrolling interests		4,259	4,187
Total equity		15,205	22,474
Total liabilities and equity		50,383	58,674
FCX Issuer [Member]
ASSETS
Current assets		139	323
Property, plant, equipment and mining development costs, net		27	22
Oil and gas properties, net - full cost method
Subject to amortization, less accumulated amortization		0	0
Not subject to amortization		0	0
Investments in consolidated subsidiaries		23,276	28,765
Other assets		8,426	8,914
Total assets		31,868	38,024
LIABILITIES AND EQUITY
Current liabilities		4,546	1,592
Long-term debt, less current portion		15,256	14,930
Deferred income taxes	[1]	1,067	3,161
Environmental and asset retirement obligations, less current portion		0	0
Other liabilities		53	54
Total liabilities		20,922	19,737
Redeemable noncontrolling interest		0	0
Equity:
Stockholders' equity		10,946	18,287
Noncontrolling interests		0	0
Total equity		10,946	18,287
Total liabilities and equity		31,868	38,024
FM O&G LLC Guarantor [Member]
ASSETS
Current assets		3,619	2,635
Property, plant, equipment and mining development costs, net		55	46
Oil and gas properties, net - full cost method
Subject to amortization, less accumulated amortization		1,020	3,296
Not subject to amortization		1,648	2,447
Investments in consolidated subsidiaries		0	6,460
Other assets		4,918	3,947
Total assets		11,260	18,831
LIABILITIES AND EQUITY
Current liabilities		522	560
Long-term debt, less current portion		5,560	3,874
Deferred income taxes		0	0
Environmental and asset retirement obligations, less current portion		322	302
Other liabilities		3,361	3,372
Total liabilities		9,765	8,108
Redeemable noncontrolling interest		0	0
Equity:
Stockholders' equity		1,495	10,723
Noncontrolling interests		0	0
Total equity		1,495	10,723
Total liabilities and equity		11,260	18,831
Non-Guarantor Subsidiaries [Member]
ASSETS
Current assets		10,291	8,659
Property, plant, equipment and mining development costs, net		27,273	26,152
Oil and gas properties, net - full cost method
Subject to amortization, less accumulated amortization		1,980	5,907
Not subject to amortization		5,914	7,640
Investments in consolidated subsidiaries		1,495	10,246
Other assets		4,232	4,061
Total assets		51,185	62,665
LIABILITIES AND EQUITY
Current liabilities		5,641	5,592
Long-term debt, less current portion		10,553	8,879
Deferred income taxes		3,296	3,237
Environmental and asset retirement obligations, less current portion		3,386	3,345
Other liabilities		1,805	1,910
Total liabilities		24,681	22,963
Redeemable noncontrolling interest		761	751
Equity:
Stockholders' equity		22,018	35,268
Noncontrolling interests		3,725	3,683
Total equity		25,743	38,951
Total liabilities and equity		51,185	62,665
Eliminations [Member]
ASSETS
Current assets		(5,894)	(2,572)
Property, plant, equipment and mining development costs, net		0	0
Oil and gas properties, net - full cost method
Subject to amortization, less accumulated amortization		2	(16)
Not subject to amortization		6	0
Investments in consolidated subsidiaries		(24,771)	(45,471)
Other assets		(13,273)	(12,787)
Total assets		(43,930)	(60,846)
LIABILITIES AND EQUITY
Current liabilities		(5,882)	(2,572)
Long-term debt, less current portion		(11,577)	(9,312)
Deferred income taxes		0	0
Environmental and asset retirement obligations, less current portion		0	0
Other liabilities		(3,492)	(3,475)
Total liabilities		(20,951)	(15,359)
Redeemable noncontrolling interest		0	0
Equity:
Stockholders' equity		(23,513)	(45,991)
Noncontrolling interests		534	504
Total equity		(22,979)	(45,487)
Total liabilities and equity		$ (43,930)	$ (60,846)

[1] All U.S. related deferred income taxes are recorded at the parent company.