Guarantor Financial Statements (Unaudited) Condensed Consolidating Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues	$ 3,792	$ 4,868
Total costs and expenses	3,471	3,409
Operating income (loss)	321	1,459
Interest expense, net	(146)	(151)
Other Nonoperating Income (Expense)	8	28
Net loss on early extinguishment of debt	(6)	(1)
Income from continuing operations before income taxes and equity in affiliated companies’ net losses	183	1,336
Provision for income taxes	(105)	(506)
Equity in affiliated companies’ net earnings (losses)	(3)	(2)
Net income from continuing operations	75	828
Net gain (loss) from discontinued operations	1	(11)
Net income	76	817
Net income from continuing operations attributable to noncontrolling interests	(45)	(125)
Net income attributable to common stockholders	31	692
Other comprehensive income (loss)	11	12
Total comprehensive income (loss)	42	704
Eliminations [Member]
Revenues	0	0
Total costs and expenses	(2)	(1)
Operating income (loss)	2	1
Interest expense, net	139	102
Other Nonoperating Income (Expense)	(73)	(102)
Income from continuing operations before income taxes and equity in affiliated companies’ net losses	68	1
Provision for income taxes	0	0
Equity in affiliated companies’ net earnings (losses)	(15)	(749)
Net income from continuing operations	53	(748)
Net gain (loss) from discontinued operations	0	0
Net income	53	(748)
Net income from continuing operations attributable to noncontrolling interests	(11)	(54)
Net income attributable to common stockholders	42	(802)
Other comprehensive income (loss)	(11)	(12)
Total comprehensive income (loss)	31	(814)
FCX Issuer [Member] | Reportable Legal Entities [Member]
Revenues	0	0
Total costs and expenses	13	9
Operating income (loss)	(13)	(9)
Interest expense, net	(90)	(104)
Other Nonoperating Income (Expense)	65	101
Income from continuing operations before income taxes and equity in affiliated companies’ net losses	(38)	(12)
Provision for income taxes	(1)	(83)
Equity in affiliated companies’ net earnings (losses)	70	787
Net income from continuing operations	31	692
Net gain (loss) from discontinued operations	0	0
Net income	31	692
Net income from continuing operations attributable to noncontrolling interests	0	0
Net income attributable to common stockholders	31	692
Other comprehensive income (loss)	11	12
Total comprehensive income (loss)	42	704
FM O&G LLC Guarantor [Member] | Reportable Legal Entities [Member]
Revenues	3	15
Total costs and expenses	0	8
Operating income (loss)	3	7
Interest expense, net	(86)	(64)
Other Nonoperating Income (Expense)	0	0
Income from continuing operations before income taxes and equity in affiliated companies’ net losses	(83)	(57)
Provision for income taxes	18	12
Equity in affiliated companies’ net earnings (losses)	5	(6)
Net income from continuing operations	(60)	(51)
Net gain (loss) from discontinued operations	0	0
Net income	(60)	(51)
Net income from continuing operations attributable to noncontrolling interests	0	0
Net income attributable to common stockholders	(60)	(51)
Other comprehensive income (loss)	0	0
Total comprehensive income (loss)	(60)	(51)
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenues	3,789	4,853
Total costs and expenses	3,460	3,393
Operating income (loss)	329	1,460
Interest expense, net	(109)	(85)
Other Nonoperating Income (Expense)	16	29
Income from continuing operations before income taxes and equity in affiliated companies’ net losses	236	1,404
Provision for income taxes	(122)	(435)
Equity in affiliated companies’ net earnings (losses)	(63)	(34)
Net income from continuing operations	51	935
Net gain (loss) from discontinued operations	1	(11)
Net income	52	924
Net income from continuing operations attributable to noncontrolling interests	(34)	(71)
Net income attributable to common stockholders	18	853
Other comprehensive income (loss)	11	12
Total comprehensive income (loss)	$ 29	$ 865