Guarantor Financial Statements (Unaudited) Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	$ 3,952	$ 4,163	$ 4,631	$ 4,403
Cash flow from operating activities:
Net cash provided by operating activities	1,369	792
Cash flow from investing activities:
Capital expenditures	(402)	(344)
Intercompany loans	0	0
Dividends from (investments in) consolidated subsidiaries	0	0
Asset sales and other, net	(90)	(17)
Net cash used in investing activities	(492)	(361)
Cash flow from financing activities:
Proceeds from debt	122	157
Repayments of debt	(1,633)	(815)
Intercompany loans	0	0
Cash dividends paid and contributions received, net	(80)	(16)
Other, net	3	(5)
Net cash used in financing activities	(1,588)	(679)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(711)	(248)
Increase (Decrease) In Cash And Cash Equivalents In Assets Held For Sale	32	8
Eliminations [Member]
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	0	0	0	0
Cash flow from operating activities:
Net cash provided by operating activities	0	0
Cash flow from investing activities:
Capital expenditures	0	0
Intercompany loans	184	277
Dividends from (investments in) consolidated subsidiaries	(1,769)	(920)
Asset sales and other, net	0	0
Net cash used in investing activities	(1,585)	(643)
Cash flow from financing activities:
Proceeds from debt	0	0
Repayments of debt	0	0
Intercompany loans	(184)	(277)
Cash dividends paid and contributions received, net	1,755	880
Other, net	14	40
Net cash used in financing activities	1,585	643
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	0	0
Increase (Decrease) In Cash And Cash Equivalents In Assets Held For Sale	0	0
Reportable Legal Entities [Member] \| FCX Issuer [Member]
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	0	0	0	0
Cash flow from operating activities:
Net cash provided by operating activities	(156)	(112)
Cash flow from investing activities:
Capital expenditures	0	0
Intercompany loans	(184)	(277)
Dividends from (investments in) consolidated subsidiaries	1,746	894
Asset sales and other, net	0	0
Net cash used in investing activities	1,562	617
Cash flow from financing activities:
Proceeds from debt	0	0
Repayments of debt	(1,409)	(499)
Intercompany loans	0	0
Cash dividends paid and contributions received, net	0	(1)
Other, net	3	(5)
Net cash used in financing activities	(1,406)	(505)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	0	0
Increase (Decrease) In Cash And Cash Equivalents In Assets Held For Sale	0	0
Reportable Legal Entities [Member] \| Guarantor Subsidiaries [Member]
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	0	8	8	11
Cash flow from operating activities:
Net cash provided by operating activities	(70)	(200)
Cash flow from investing activities:
Capital expenditures	0	(10)
Intercompany loans	0	0
Dividends from (investments in) consolidated subsidiaries	0	0
Asset sales and other, net	0	(23)
Net cash used in investing activities	0	(33)
Cash flow from financing activities:
Proceeds from debt	0	0
Repayments of debt	0	0
Intercompany loans	62	236
Cash dividends paid and contributions received, net	0	0
Other, net	0	(6)
Net cash used in financing activities	62	230
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(8)	(3)
Increase (Decrease) In Cash And Cash Equivalents In Assets Held For Sale	0	0
Reportable Legal Entities [Member] \| Non-Guarantor Subsidiaries [Member]
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	3,952	4,155	$ 4,623	$ 4,392
Cash flow from operating activities:
Net cash provided by operating activities	1,595	1,104
Cash flow from investing activities:
Capital expenditures	(402)	(334)
Intercompany loans	0	0
Dividends from (investments in) consolidated subsidiaries	23	26
Asset sales and other, net	(90)	6
Net cash used in investing activities	(469)	(302)
Cash flow from financing activities:
Proceeds from debt	122	157
Repayments of debt	(224)	(316)
Intercompany loans	122	41
Cash dividends paid and contributions received, net	(1,835)	(895)
Other, net	(14)	(34)
Net cash used in financing activities	(1,829)	(1,047)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(703)	(245)
Increase (Decrease) In Cash And Cash Equivalents In Assets Held For Sale	$ 32	$ 8

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The net cash outflow or inflow from other investing activities, excluding investment in subsidiaries. This element is used when there is not a more specific and appropriate element in the taxonomy.

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The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. This concept relates to payments that are investing activities.

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Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Alternate caption: Proceeds from (Payments for) Advances to Affiliates.

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Amount of cash inflow (outflow) from financing activities classified as other.

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The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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No definition available.

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