CONTINGENCIES (Tax and Other Matters) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016	Dec. 31, 2014
Income Tax Examination [Line Items]
Income Taxes Receivable, Noncurrent	$ 445,000,000	$ 129,000,000
Proceeds from Income Tax Refunds	329,000,000	247,000,000	$ 334,000,000
PT-FI
Income Tax Examination [Line Items]
Penalty and Interest Assessment	0
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority				$ (196,000,000)
Value Added Tax Receivable					$ 269,000,000
SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	253,000,000
Penalty and Interest Assessment	364,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	617,000,000
Income Taxes Receivable, Noncurrent	288,000,000
Increase (Decrease) in Income Taxes Receivable	103,000,000
Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	795,000,000
Income Tax Examination, Interest Accrued	186,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	981,000,000
2003 to 2005 | SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	16,000,000
Penalty and Interest Assessment	54,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	70,000,000
2005 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	77,000,000
Income Tax Examination, Interest Accrued	37,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	114,000,000
2005 | Indonesian Supreme Court [Member] | Maximum | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	1,000,000
2006 | SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	7,000,000
Penalty and Interest Assessment	59,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	66,000,000
2007 to 2008 | SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	33,000,000
Penalty and Interest Assessment	31,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	64,000,000
2007 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	48,000,000
Income Tax Examination, Interest Accrued	24,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	72,000,000
Tax Year, 2008, 2010 to Tax Year 2011 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	56,000,000
Income Tax Examination, Interest Accrued	37,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	93,000,000
2009 | SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	59,000,000
Penalty and Interest Assessment	49,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	108,000,000
2010 | SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	66,000,000
Penalty and Interest Assessment	107,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	173,000,000
2012 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	125,000,000
Income Tax Examination, Interest Accrued	1,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	126,000,000
2013 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	160,000,000
Income Tax Examination, Interest Accrued	80,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	240,000,000
2014 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	160,000,000
Income Tax Examination, Interest Accrued	7,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	167,000,000
2015 | Indonesian Tax Authority | PT-FI
Income Tax Examination [Line Items]
Tax Assessment	169,000,000
Income Tax Examination, Interest Accrued	0
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	169,000,000
Relating to 2011 through 2015 | Tax Authority, In Papau, Indonesia | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	400,000,000
Relating to 2011 through 2017 | Tax Authority, In Papau, Indonesia | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	530,000,000
2011, 2014 to 2017 | SUNAT | Cerro Verde
Income Tax Examination [Line Items]
Tax Assessment	72,000,000
Penalty and Interest Assessment	64,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	136,000,000
2016 to 2017 | Tax Authority, In Papau, Indonesia | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	130,000,000
The year 2005 and the year 2007 [Member] | Indonesian Supreme Court [Member] | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	66,000,000
Cerro Verde
Income Tax Examination [Line Items]
Income Taxes Receivable, Noncurrent	185,000,000	277,000,000
PT-FI
Income Tax Examination [Line Items]
Income Taxes Receivable, Noncurrent	417,000,000	$ 331,000,000
Penalties [Member] | Relating to 2011 through 2015 | Tax Authority, In Papau, Indonesia | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	239,000,000
Penalties [Member] | 2016 to 2017 | Tax Authority, In Papau, Indonesia | PT-FI
Income Tax Examination [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 65,000,000
Other Liabilities [Member] | PT-FI
Income Tax Examination [Line Items]
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority				$ (38,000,000)