Guarantor Financial Statements (Unaudited) Condensed Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues	$ 4,868	$ 3,341
Total costs and expenses	3,409	2,744
Operating income (loss)	1,459	597
Interest expense, net	(151)	(167)
Other Nonoperating Income (Expense)	28	8
Income from continuing operations before income taxes and equity in affiliated companies’ net (losses) earnings	1,336	438
Provision for income taxes	(506)	(174)
Equity in affiliated companies’ net earnings (losses)	(2)	4
Net income from continuing operations	828	268
Net (loss) income from discontinued operations	(11)	38
Net income (loss)	817	306
Net income from continuing operations attributable to noncontrolling interests	125	75
Discontinued operations	0	(3)
Net income attributable to common stockholders	692	228
Other comprehensive income (loss)	12	11
Total comprehensive income (loss)	704	239
Eliminations [Member]
Revenues	0	0
Total costs and expenses	(1)	2
Operating income (loss)	1	(2)
Interest expense, net	102	79
Other Nonoperating Income (Expense)	(102)	(79)
Income from continuing operations before income taxes and equity in affiliated companies’ net (losses) earnings	1	(2)
Provision for income taxes	0	1
Equity in affiliated companies’ net earnings (losses)	(749)	(320)
Net income from continuing operations	(748)	(321)
Net (loss) income from discontinued operations	0	0
Net income (loss)	(748)	(321)
Net income from continuing operations attributable to noncontrolling interests	54	10
Discontinued operations		0
Net income attributable to common stockholders	(802)	(331)
Other comprehensive income (loss)	(12)	(11)
Total comprehensive income (loss)	(814)	(342)
FCX Issuer [Member] | Reportable Legal Entities [Member]
Revenues	0	0
Total costs and expenses	9	8
Operating income (loss)	(9)	(8)
Interest expense, net	(104)	(122)
Other Nonoperating Income (Expense)	101	78
Income from continuing operations before income taxes and equity in affiliated companies’ net (losses) earnings	(12)	(52)
Provision for income taxes	(83)	(60)
Equity in affiliated companies’ net earnings (losses)	787	340
Net income from continuing operations	692	228
Net (loss) income from discontinued operations	0	0
Net income (loss)	692	228
Net income from continuing operations attributable to noncontrolling interests	0	0
Discontinued operations		0
Net income attributable to common stockholders	692	228
Other comprehensive income (loss)	12	11
Total comprehensive income (loss)	704	239
FM O&G LLC Guarantor [Member] | Reportable Legal Entities [Member]
Revenues	15	13
Total costs and expenses	8	50
Operating income (loss)	7	(37)
Interest expense, net	(64)	(53)
Other Nonoperating Income (Expense)	0	0
Income from continuing operations before income taxes and equity in affiliated companies’ net (losses) earnings	(57)	(90)
Provision for income taxes	12	31
Equity in affiliated companies’ net earnings (losses)	(6)	20
Net income from continuing operations	(51)	(39)
Net (loss) income from discontinued operations	0	0
Net income (loss)	(51)	(39)
Net income from continuing operations attributable to noncontrolling interests	0	0
Discontinued operations		0
Net income attributable to common stockholders	(51)	(39)
Other comprehensive income (loss)	0	0
Total comprehensive income (loss)	(51)	(39)
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenues	4,853	3,328
Total costs and expenses	3,393	2,684
Operating income (loss)	1,460	644
Interest expense, net	(85)	(71)
Other Nonoperating Income (Expense)	29	9
Income from continuing operations before income taxes and equity in affiliated companies’ net (losses) earnings	1,404	582
Provision for income taxes	(435)	(146)
Equity in affiliated companies’ net earnings (losses)	(34)	(36)
Net income from continuing operations	935	400
Net (loss) income from discontinued operations	(11)	38
Net income (loss)	924	438
Net income from continuing operations attributable to noncontrolling interests	71	65
Discontinued operations		(3)
Net income attributable to common stockholders	853	370
Other comprehensive income (loss)	12	11
Total comprehensive income (loss)	$ 865	$ 381