Guarantor Financial Statements (Unaudited) Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	$ 3,112	$ 3,999	$ 4,455	$ 4,710
Cash flow from operating activities:
Net cash provided by operating activities	534	1,369
Cash flow from investing activities:
Capital expenditures	(622)	(402)
Intercompany loans	0	0
Dividends from (investments in) consolidated subsidiaries	(2)	0
Proceeds From Divestiture Of Business And Interests In Affiliates And Proceeds From Sale Of Other Assets	78	(90)
Net cash used in investing activities	(546)	(492)
Cash flow from financing activities:
Proceeds from debt	114	122
Repayments of debt	(1,356)	(1,633)
Intercompany loans	0	0
Cash dividends paid and contributions received, net	(82)	(80)
Other, net	(7)	3
Net cash used in financing activities	(1,331)	(1,588)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(1,343)	(711)
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	159	184
Dividends from (investments in) consolidated subsidiaries	(1,251)	(1,769)
Proceeds From Divestiture Of Business And Interests In Affiliates And Proceeds From Sale Of Other Assets	0	0
Net cash used in investing activities	(1,092)	(1,585)
Cash flow from financing activities:
Proceeds from debt	0	0
Repayments of debt	0	0
Intercompany loans	(159)	(184)
Cash dividends paid and contributions received, net	1,233	1,755
Other, net	18	14
Net cash used in financing activities	1,092	1,585
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	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	19	(156)
Cash flow from investing activities:
Capital expenditures	0	0
Intercompany loans	(159)	(184)
Dividends from (investments in) consolidated subsidiaries	1,224	1,746
Proceeds From Divestiture Of Business And Interests In Affiliates And Proceeds From Sale Of Other Assets	(1)	0
Net cash used in investing activities	1,064	1,562
Cash flow from financing activities:
Proceeds from debt	0	0
Repayments of debt	(1,003)	(1,409)
Intercompany loans	0	0
Cash dividends paid and contributions received, net	(73)	0
Other, net	(7)	3
Net cash used in financing activities	(1,083)	(1,406)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	0	0
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	0	0	0	8
Cash flow from operating activities:
Net cash provided by operating activities	(106)	(70)
Cash flow from investing activities:
Capital expenditures	0	0
Intercompany loans	0	0
Dividends from (investments in) consolidated subsidiaries	0	0
Proceeds From Divestiture Of Business And Interests In Affiliates And Proceeds From Sale Of Other Assets	84	0
Net cash used in investing activities	84	0
Cash flow from financing activities:
Proceeds from debt	0	0
Repayments of debt	0	0
Intercompany loans	22	62
Cash dividends paid and contributions received, net	0	0
Other, net	0	0
Net cash used in financing activities	22	62
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	0	(8)
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Cash, cash equivalents, restricted cash and restricted cash equivalents at beginning of year	3,112	3,999	$ 4,455	$ 4,702
Cash flow from operating activities:
Net cash provided by operating activities	621	1,595
Cash flow from investing activities:
Capital expenditures	(622)	(402)
Intercompany loans	0	0
Dividends from (investments in) consolidated subsidiaries	25	23
Proceeds From Divestiture Of Business And Interests In Affiliates And Proceeds From Sale Of Other Assets	(5)	(90)
Net cash used in investing activities	(602)	(469)
Cash flow from financing activities:
Proceeds from debt	114	122
Repayments of debt	(353)	(224)
Intercompany loans	137	122
Cash dividends paid and contributions received, net	(1,242)	(1,835)
Other, net	(18)	(14)
Net cash used in financing activities	(1,362)	(1,829)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	$ (1,343)	$ (703)