Business Segments (Segment Reporting) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) segment	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of Operating Segments | segment			4
Deferred Intercompany Profit, Percentage			25.00%
Revenues	$ 3,546	$ 5,168	$ 7,338	$ 10,036
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(3,002)	(2,915)	(5,978)	(5,723)
Cost, Depreciation, Amortization and Depletion	352	442	699	893
Metals inventory adjustments	2		59	2
Selling, general and administrative expenses	(97)	(109)	(209)	(240)
Mining exploration and research expenses	31	24	58	45
Environmental obligations and shutdown costs	23	59	65	68
Net gain on sales of assets	8	(45)	(25)	(56)
Operating income	33	1,664	354	3,123
Interest expense, net	(132)	(142)	(278)	(293)
Provision for (benefit from) income taxes	(15)	515	90	1,021
Total assets	41,086	37,028	41,086	37,028	$ 42,216
Capital expenditures	629	482	1,251	884
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenues	85	38	192	56
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(825)	(789)	(1,568)	(1,580)
Cost, Depreciation, Amortization and Depletion	87	92	170	186
Selling, general and administrative expenses	0	(1)	(2)	(4)
Mining exploration and research expenses	1	0	1	1
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	207	365	413	784
Interest expense, net	(1)	(1)	(2)	(2)
Provision for (benefit from) income taxes	0	0	0	0
Total assets	7,838	7,193	7,838	7,193
Capital expenditures	207	140	417	232
Operating Segments | South America
Segment Reporting Information [Line Items]
Revenues	690	890	1,515	1,665
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(581)	(578)	(1,120)	(1,121)
Cost, Depreciation, Amortization and Depletion	119	133	233	260
Selling, general and administrative expenses	(2)	(2)	(4)	(4)
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	59	277	355	482
Interest expense, net	(25)	(16)	(54)	(33)
Provision for (benefit from) income taxes	11	108	116	180
Total assets	10,270	10,345	10,270	10,345
Capital expenditures	47	71	108	138
Corporate And Eliminations
Segment Reporting Information [Line Items]
Revenues	471	612	927	1,204
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	722	916	1,340	1,910
Cost, Depreciation, Amortization and Depletion	19	14	39	35
Selling, general and administrative expenses	(60)	(73)	(133)	(154)
Mining exploration and research expenses	30	24	57	44
Environmental obligations and shutdown costs	23	59	65	68
Net gain on sales of assets	8	(45)	(25)	(56)
Operating income	(165)	(26)	(433)	(109)
Interest expense, net	(99)	(119)	(209)	(247)
Provision for (benefit from) income taxes	7	(22)	(20)	10
Total assets	3,911	5,550	3,911	5,550
Capital expenditures	28	20	51	54
Intersegment
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Intersegment | North America
Segment Reporting Information [Line Items]
Revenues	1,035	1,209	1,962	2,499
Intersegment | South America
Segment Reporting Information [Line Items]
Revenues	71	100	197	202
Pt Smelting | Affiliated Entity [Member]
Segment Reporting Information [Line Items]
Revenues	470	649	879	1,300
Morenci [Member] | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenues	16	25	28	28
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(348)	(298)	(643)	(588)
Cost, Depreciation, Amortization and Depletion	43	44	83	90
Selling, general and administrative expenses	0	(1)	(1)	(2)
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	116	250	250	517
Interest expense, net	(1)	(1)	(2)	(2)
Provision for (benefit from) income taxes	0	0	0	0
Total assets	2,917	2,819	2,917	2,819
Capital expenditures	49	41	111	88
Morenci [Member] | Intersegment | North America
Segment Reporting Information [Line Items]
Revenues	491	568	949	1,169
Other Individually Immaterial Operating Segments [Member] | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenues	69	13	164	28
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(477)	(491)	(925)	(992)
Cost, Depreciation, Amortization and Depletion	44	48	87	96
Selling, general and administrative expenses	0	0	(1)	(2)
Mining exploration and research expenses	1	0	1	1
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	91	115	163	267
Interest expense, net	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Total assets	4,921	4,374	4,921	4,374
Capital expenditures	158	99	306	144
Other Individually Immaterial Operating Segments [Member] | Operating Segments | South America
Segment Reporting Information [Line Items]
Revenues	128	171	226	321
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(126)	(133)	(226)	(249)
Cost, Depreciation, Amortization and Depletion	18	24	32	46
Selling, general and administrative expenses	0	0	0	0
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	(16)	14	(32)	26
Interest expense, net	0	0	0	0
Provision for (benefit from) income taxes	(9)	6	(14)	10
Total assets	1,699	1,715	1,699	1,715
Capital expenditures	4	3	9	7
Other Individually Immaterial Operating Segments [Member] | Intersegment | North America
Segment Reporting Information [Line Items]
Revenues	544	641	1,013	1,330
Other Individually Immaterial Operating Segments [Member] | Intersegment | South America
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Cerro Verde [Member] | Operating Segments | South America
Segment Reporting Information [Line Items]
Revenues	562	719	1,289	1,344
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(455)	(445)	(894)	(872)
Cost, Depreciation, Amortization and Depletion	101	109	201	214
Selling, general and administrative expenses	(2)	(2)	(4)	(4)
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	75	263	387	456
Interest expense, net	(25)	(16)	(54)	(33)
Provision for (benefit from) income taxes	20	102	130	170
Total assets	8,571	8,630	8,571	8,630
Capital expenditures	43	68	99	131
Cerro Verde [Member] | Intersegment | South America
Segment Reporting Information [Line Items]
Revenues	71	100	197	202
Grasberg Segment [Member]
Segment Reporting Information [Line Items]
Capital expenditures			658	449
Grasberg Segment [Member] | Operating Segments | Indonesia
Segment Reporting Information [Line Items]
Revenues	583	1,639	1,288	3,160
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(554)	(425)	(1,110)	(882)
Cost, Depreciation, Amortization and Depletion	99	172	204	353
Selling, general and administrative expenses	(30)	(28)	(60)	(67)
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	(101)	1,015	(29)	1,911
Interest expense, net	(1)	0	(1)	0
Provision for (benefit from) income taxes	(35)	429	(9)	830
Total assets	16,261	10,911	16,261	10,911
Capital expenditures	339	246	658	449
Grasberg Segment [Member] | Intersegment | Indonesia
Segment Reporting Information [Line Items]
Revenues	(1)	1	57	53
Molybdenum [Member]
Segment Reporting Information [Line Items]
Capital expenditures			6	2
Molybdenum [Member] | Operating Segments
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(78)	(71)	(149)	(138)
Cost, Depreciation, Amortization and Depletion	18	21	34	40
Selling, general and administrative expenses	0	0	0	0
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	13	19	17	28
Interest expense, net	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Total assets	1,792	1,820	1,792	1,820
Capital expenditures	2	1	6	2
Molybdenum [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	109	111	200	206
Rod and Refining Segment [Member] | Operating Segments
Segment Reporting Information [Line Items]
Revenues	1,171	1,387	2,299	2,772
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(1,171)	(1,389)	(2,304)	(2,777)
Cost, Depreciation, Amortization and Depletion	3	3	5	5
Selling, general and administrative expenses	0	0	0	0
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	1	3	0	6
Interest expense, net	0	0	0	0
Provision for (benefit from) income taxes	0	0	0	0
Total assets	250	278	250	278
Capital expenditures	1	1	2	2
Rod and Refining Segment [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	4	8	10	16
Atlantic Copper Smelting and Refining Segment [Member] | Operating Segments
Segment Reporting Information [Line Items]
Revenues	546	602	1,117	1,179
Cost of Goods Sold, Excluding Depreciation, Depletion, and Amortization (Deprecated 2019-01-31)	(515)	(579)	(1,067)	(1,135)
Cost, Depreciation, Amortization and Depletion	7	7	14	14
Selling, general and administrative expenses	(5)	(5)	(10)	(11)
Mining exploration and research expenses	0	0	0	0
Environmental obligations and shutdown costs	0	0	0	0
Net gain on sales of assets	0	0	0	0
Operating income	19	11	31	21
Interest expense, net	(6)	(6)	(12)	(11)
Provision for (benefit from) income taxes	2	0	3	1
Total assets	764	931	764	931
Capital expenditures	5	3	9	7
Atlantic Copper Smelting and Refining Segment [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	0	0	5	2
Corporate And Eliminations | Intersegment
Segment Reporting Information [Line Items]
Revenues	$ (1,218)	$ (1,429)	$ (2,431)	$ (2,978)