GUARANTOR FINANCIAL STATEMENTS (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Assets, Current	$ 10,779	$ 10,435
Current assets held for sale	598	344
Property, plant, equipment and mine development costs, net	22,836	23,219
Oil and gas properties, net - full cost method:
Oil and gas properties subject to amortization, less accumulated amortization and impairments	8	74
Investments in consolidated subsidiaries	0	0
Other assets	3,679	3,589
Assets held for sale			$ 4,400
Total assets	37,302	37,317	46,577
LIABILITIES AND EQUITY
Liabilities, Current	5,038	4,265
Current liabilities held for sale	350	205
Long-term debt, less current portion	11,703	14,795
Deferred income taxes	3,622	3,768
Environmental and asset retirement obligations, less current portion	3,631	3,487
Investments in consolidated subsidiary	0	0
Other Liabilities, Noncurrent	2,012	1,745
Total liabilities	26,006	28,060
Equity:
Stockholders' equity	7,977	6,051
Noncontrolling interests	3,319	3,206
Total equity	11,296	9,257	$ 12,044	$ 22,474
Total liabilities and equity	37,302	37,317
Eliminations
ASSETS
Assets, Current	(790)	(3,260)
Property, plant, equipment and mine development costs, net	(10)	0
Oil and gas properties, net - full cost method:
Oil and gas properties subject to amortization, less accumulated amortization and impairments	0	0
Investments in consolidated subsidiaries	(19,570)	(21,110)
Other assets	(491)	(1,965)
Total assets	(20,861)	(26,335)
LIABILITIES AND EQUITY
Liabilities, Current	(938)	(3,244)
Long-term debt, less current portion	(10,270)	(15,081)
Deferred income taxes	0	0
Environmental and asset retirement obligations, less current portion	0	0
Investments in consolidated subsidiary	(11,250)	(9,888)
Other Liabilities, Noncurrent	(3,488)	(3,487)
Total liabilities	(25,946)	(31,700)
Equity:
Stockholders' equity	4,480	4,758
Noncontrolling interests	605	607
Total equity	5,085	5,365
Total liabilities and equity	(20,861)	(26,335)
FCX Issuer | Reportable Legal Entities
ASSETS
Assets, Current	75	230
Property, plant, equipment and mine development costs, net	14	19
Oil and gas properties, net - full cost method:
Oil and gas properties subject to amortization, less accumulated amortization and impairments	0	0
Investments in consolidated subsidiaries	19,570	21,110
Other assets	943	1,985
Total assets	20,602	23,344
LIABILITIES AND EQUITY
Liabilities, Current	1,683	3,895
Long-term debt, less current portion	10,021	12,517
Deferred income taxes	748	826
Environmental and asset retirement obligations, less current portion	0	0
Investments in consolidated subsidiary	0	0
Other Liabilities, Noncurrent	173	55
Total liabilities	12,625	17,293
Equity:
Stockholders' equity	7,977	6,051
Noncontrolling interests	0	0
Total equity	7,977	6,051
Total liabilities and equity	20,602	23,344
FM O&G LLC Guarantor | Reportable Legal Entities
ASSETS
Assets, Current	671	1,790
Property, plant, equipment and mine development costs, net	11	24
Oil and gas properties, net - full cost method:
Oil and gas properties subject to amortization, less accumulated amortization and impairments	0	0
Investments in consolidated subsidiaries	0	0
Other assets	48	47
Total assets	730	1,861
LIABILITIES AND EQUITY
Liabilities, Current	220	308
Long-term debt, less current portion	6,512	6,062
Deferred income taxes	0	0
Environmental and asset retirement obligations, less current portion	201	200
Investments in consolidated subsidiary	853	893
Other Liabilities, Noncurrent	3,340	3,393
Total liabilities	11,126	10,856
Equity:
Stockholders' equity	(10,396)	(8,995)
Noncontrolling interests	0	0
Total equity	(10,396)	(8,995)
Total liabilities and equity	730	1,861
Non-Guarantor Subsidiaries | Reportable Legal Entities
ASSETS
Assets, Current	10,823	11,675
Property, plant, equipment and mine development costs, net	22,821	23,176
Oil and gas properties, net - full cost method:
Oil and gas properties subject to amortization, less accumulated amortization and impairments	8	74
Investments in consolidated subsidiaries	0	0
Other assets	3,179	3,522
Total assets	36,831	38,447
LIABILITIES AND EQUITY
Liabilities, Current	4,073	3,306
Long-term debt, less current portion	5,440	11,297
Deferred income taxes	2,874	2,942
Environmental and asset retirement obligations, less current portion	3,430	3,287
Investments in consolidated subsidiary	10,397	8,995
Other Liabilities, Noncurrent	1,987	1,784
Total liabilities	28,201	31,611
Equity:
Stockholders' equity	5,916	4,237
Noncontrolling interests	2,714	2,599
Total equity	8,630	6,836
Total liabilities and equity	$ 36,831	$ 38,447