Business Segments (Segment Reporting) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Number of Operating Segments	4
Revenues	$ 4,868	$ 3,341
Production and delivery	2,808	2,188
Depreciation, depletion and amortization	451	389
Selling, general and administrative expenses	131	151
Mining exploration and research expenses	21	14
Environmental obligations and shutdown costs	9	25
Net gain on sales of assets	(11)	(23)
Operating income (loss)	1,459	597
Interest expense, net	151	167
Provision for (benefit from) income taxes	506	174
Total assets	36,637	36,576	$ 37,302
Capital expenditures	402	344
Assets held for sale	708	408	$ 598
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenues	18	116
Production and delivery	791	666
Depreciation, depletion and amortization	94	116
Selling, general and administrative expenses	3	1
Mining exploration and research expenses	1	1
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	419	311
Interest expense, net	1	1
Provision for (benefit from) income taxes	0	0
Total assets	7,157	7,175
Capital expenditures	92	28
Operating Segments | South America
Segment Reporting Information [Line Items]
Revenues	775	752
Production and delivery	543	473
Depreciation, depletion and amortization	127	133
Selling, general and administrative expenses	2	2
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	205	260
Interest expense, net	17	16
Provision for (benefit from) income taxes	72	101
Total assets	10,455	10,606
Capital expenditures	67	15
Corporate And Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	592	374
Production and delivery	(994)	(818)
Depreciation, depletion and amortization	21	29
Selling, general and administrative expenses	81	113
Mining exploration and research expenses	20	13
Environmental obligations and shutdown costs	9	25
Net gain on sales of assets	(11)	(23)
Operating income (loss)	(83)	(131)
Interest expense, net	128	146
Provision for (benefit from) income taxes	32	5
Total assets	5,098	5,547
Capital expenditures	34	47
Intersegment
Segment Reporting Information [Line Items]
Revenues	0	0
Intersegment | North America
Segment Reporting Information [Line Items]
Revenues	1,290	979
Intersegment | South America
Segment Reporting Information [Line Items]
Revenues	102	116
Pt Smelting [Member] | Affiliated Entity [Member]
Segment Reporting Information [Line Items]
Revenues	$ 628	258
Pt Smelting [Member]
Segment Reporting Information [Line Items]
Deferred Intercompany Profit, Percentage	25.00%
Morenci [Member] | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenues	$ 3	66
Production and delivery	290	257
Depreciation, depletion and amortization	46	47
Selling, general and administrative expenses	1	0
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	267	178
Interest expense, net	1	1
Provision for (benefit from) income taxes	0	0
Total assets	2,817	2,814
Capital expenditures	47	23
Morenci [Member] | Intersegment | North America
Segment Reporting Information [Line Items]
Revenues	601	416
Other Individually Immaterial Operating Segments [Member] | Operating Segments | North America
Segment Reporting Information [Line Items]
Revenues	15	50
Production and delivery	501	409
Depreciation, depletion and amortization	48	69
Selling, general and administrative expenses	2	1
Mining exploration and research expenses	1	1
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	152	133
Interest expense, net	0	0
Provision for (benefit from) income taxes	0	0
Total assets	4,340	4,361
Capital expenditures	45	5
Other Individually Immaterial Operating Segments [Member] | Operating Segments | South America
Segment Reporting Information [Line Items]
Revenues	150	112
Production and delivery	116	82
Depreciation, depletion and amortization	22	21
Selling, general and administrative expenses	0	0
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	12	9
Interest expense, net	0	0
Provision for (benefit from) income taxes	4	3
Total assets	1,715	1,525
Capital expenditures	4	1
Other Individually Immaterial Operating Segments [Member] | Intersegment | North America
Segment Reporting Information [Line Items]
Revenues	689	563
Other Individually Immaterial Operating Segments [Member] | Intersegment | South America
Segment Reporting Information [Line Items]
Revenues	0	0
Cerro Verde [Member] | Operating Segments | South America
Segment Reporting Information [Line Items]
Revenues	625	640
Production and delivery	427	391
Depreciation, depletion and amortization	105	112
Selling, general and administrative expenses	2	2
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	193	251
Interest expense, net	17	16
Provision for (benefit from) income taxes	68	98
Total assets	8,740	9,081
Capital expenditures	63	14
Cerro Verde [Member] | Intersegment | South America
Segment Reporting Information [Line Items]
Revenues	102	116
Grasberg Segment [Member]
Segment Reporting Information [Line Items]
Capital expenditures	203	244
Grasberg Segment [Member] | Operating Segments | Indonesia
Segment Reporting Information [Line Items]
Revenues	1,521	534
Production and delivery	457	270
Depreciation, depletion and amortization	181	83
Selling, general and administrative expenses	39	30
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	896	151
Interest expense, net	0	0
Provision for (benefit from) income taxes	401	67
Total assets	10,992	10,418
Capital expenditures	203	244
Grasberg Segment [Member] | Intersegment | Indonesia
Segment Reporting Information [Line Items]
Revenues	52	0
Molybdenum [Member]
Segment Reporting Information [Line Items]
Capital expenditures	1	1
Molybdenum [Member] | Operating Segments
Segment Reporting Information [Line Items]
Revenues	0	0
Production and delivery	67	52
Depreciation, depletion and amortization	19	19
Selling, general and administrative expenses	0	0
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	9	(8)
Interest expense, net	0	0
Provision for (benefit from) income taxes	0	0
Total assets	1,836	1,917
Capital expenditures	1	1
Molybdenum [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	95	63
Rod and Refining Segment [Member] | Operating Segments
Segment Reporting Information [Line Items]
Revenues	1,385	1,107
Production and delivery	1,388	1,109
Depreciation, depletion and amortization	2	2
Selling, general and administrative expenses	0	0
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	3	4
Interest expense, net	0	0
Provision for (benefit from) income taxes	0	0
Total assets	290	261
Capital expenditures	1	1
Rod and Refining Segment [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	8	8
Atlantic Copper Smelting and Refining Segment [Member] | Operating Segments
Segment Reporting Information [Line Items]
Revenues	577	458
Production and delivery	556	436
Depreciation, depletion and amortization	7	7
Selling, general and administrative expenses	6	5
Mining exploration and research expenses	0	0
Environmental obligations and shutdown costs	0	0
Net gain on sales of assets	0	0
Operating income (loss)	10	10
Interest expense, net	5	4
Provision for (benefit from) income taxes	1	1
Total assets	809	652
Capital expenditures	4	8
Atlantic Copper Smelting and Refining Segment [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	2	0
Corporate And Eliminations [Member] | Intersegment
Segment Reporting Information [Line Items]
Revenues	$ (1,549)	$ (1,166)