Tax situation (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure Of Income Tax Explanatory [Line Items]

Disclosure Of Detailed Information Income Tax Years To Review [Text Block]

The Income Tax and Value Added Tax (VAT) returns for the following years are open to review by the Tax Authorities:

Entity	Years open to review by the Tax Authorities

Compañía de Minas Buenaventura S.A.A.	2015-2018
Compañía Minera Condesa S.A.	2014-2018
Compañía Minera Colquirrumi S.A.	2014-2018
Consorcio Energético de Huancavelica S.A.	2014-2018
Contacto Corredores de Seguros S.A.	2014-2018
El Molle Verde S.A.C.	2014-2018
Empresa de Generación Huanza S.A.	2015-2018
Inversiones Colquijirca S.A.	2014-2018
Minera La Zanja S.R.L.	2014,2016-2018
Sociedad Minera El Brocal S.A.A.	2014-2018
S.M.R.L. Chaupiloma Dos de Cajamarca	2014-2018
Procesadora Industrial Río Seco S. A.	2014-2018
Apu Coropuna S.R.L.	2014-2018
Cerro Hablador S. A. C.	2014-2018
Minera Azola S. R. L.	2014-2018

Minera Yanacocha SRL and subsidiary [Member]

Disclosure Of Income Tax Explanatory [Line Items]

Disclosure Of Detailed Information Income Tax Years To Review [Text Block]

The Company has entered into the following tax stability agreements, each with a term of 15 years:

Mine	Effective	Date of the Tax Agreement	Tax Regimes in Force

Cerro Yanacocha	January 1, 2000	September 16, 1998	May 22, 1997
La Quinua	January 1, 2004	August 25, 2003	August 25, 2003

Disclosure Of Detailed Information About Income Tax Provision [Text Block]

The Company's income tax provision consisted of the following:

	2018			2017			2016
	US$(000)			US$(000)			US$(000)

Current peruvian income tax		12,525			3,877			41,105
Royalties and mining taxes		8,888			4,944			10,249
Other taxes		55			211			323
Income tax prior year adjustments		8,900			(2,006	)		(2,092	)
Income tax prior years refunds		-			-			(6,458	)
Current income tax expense		30,368			7,026			43,127
Deferred income tax expenses (benefit)		(1,071	)		-			-

Income tax expense		29,297			7,026			43,127

Disclosure of detailed deferred taxes [Text Block]

Components of deferred income tax assets (liabilities) are as follows:

	2018			2017
	US$(000)			US$(000)

Deferred income tax assets, net
Property, plant and mine development		514,828			571,210
Reclamation		301,492			233,843
Accounts payable and accrued expenses		92,610			78,241
Inventories		62,363			61,435
Other		1,102			3,073
		972,395			947,802
Allowance of deferred income tax asset		(971,324	)		(947,802	)

Net deferred income tax asset		1,071			-

Disclosure Of Tax Expense Reconciliation Of Accounting Profit Multiplied By Applicable Tax Rates [Text Block]

Below is a reconciliation of tax expense and the accounts profit multiplied by the statutory tax rate for the years 2018, 2017 and 2016:

	2018			2017			2016
	US$(000)			US$(000)			US$(000)

Loss before income tax		(52,220	)		(168,428	)		(1,000,625	)
Peruvian statutory tax rate		29.5	%		29.5	%		28	%
Income tax income		(15,405	)		(49,686	)		(280,175	)
Valuation allowance on deferred tax asset		23,771			50,960			386,763
Effect of change in income tax rate					-			(66,667	)
Mining taxes		6,260			3,530			7,392
Non-deductible expenses		6,962			4,204			3,296
Adjustment due to income tax rate applicable to La Quinua		(176	)		(124	)		(1,024	)
Income tax prior years refunds / payments		7,885			(1,858	)		(6,458	)

Total income tax expense		29,297			7,026			43,127

Sociedad Minera El Brocal S.A.A. [Member]

Disclosure Of Income Tax Explanatory [Line Items]

Disclosure Of Detailed Information About Income Tax Provision [Text Block]

The income tax expense (benefit) for the years ended December 31, 2018, 2017 and 2016is shown below:

	2018		2017			2016
	US$(000)		US$(000)			US$(000)

Income tax
Current		254,767		430,974			141,153
Deferred		61,483		(167,541	)		81,441
		316,250		263,433			222,594
Mining taxes
Current mining royalty and special mining tax		6,661		213,280			37,763

Supplementary retirement fund
Current		1,499		10,897			2,205
Deferred		760		(1,567	)		520
		2,259		9,330			2,725

Income tax expense reported in the statements of comprehensive income		325,170		486,043			263,082

Disclosure of detailed information about the other tax assesment [Text Block]

Year	Taxes		Penalty and interest		Total
	US$(000)		US$(000)		US$(000)

2003 – 2005		12,220		46,710		58,930
2006		10,990		51,938		62,928
2007		12,376		17,845		30,221
2008		20,797		12,968		33,765
2009		56,388		51,219		107,607
2010		62,581		105,225		167,806
2011		49,055		65,068		114,123
2014 –2018		32,148		-		32,148

		256,555		350,973		607,528

Disclosure Of Temporary Difference Unused Tax Losses And Unused Tax Credits Explanatory [Text Block]

(g)

The Company recognizes the effect of temporary differences between the accounting base for financial reporting purposes and the tax base. The composition of this item is made up as follows:

	December 31, 2018		December 31, 2017		December 31, 2016
	US$(000)		US$(000)		US$(000)
Income tax
Asset
Royalty accrual		109,505		127,475		-
Provision for remediation and mine closure		15,131		12,083		9,180
Price adjustment of copper concentrate and cathode		6,050		-		-
Unpaid vacations		5,937		5,293		4,055
Provision for mining taxes		4,120		8,742		4,003
SUNAT Assessments		4,055		4,077		-
Cost of net asset for the construction of the tailing dam		2,638		2,007		2,321
Development costs		122		183		228
Other provisions		10,450		4,240		5,248
		158,008		164,100		25,035
Liability
Difference in depreciation method		337,642		261,434		283,882
Stripping activity asset		27,464		22,014		23,594
Difference in valuation of inventories		16,605		16,264		25,087
Debt issuance costs		1,894		2,663		-
Price adjustment of copper concentrate and cathode		-		25,840		24,128
		383,605		328,215		356,691
Deferred liabilities, net		225,597		164,115		331,656
Supplementary retirement fund
Deferred liability		2,651		1,890		3,458

Total deferred income tax liability, net		228,248		166,005		335,114

Disclosure of detailed information reconciliation of income tax rate [Text Block]

For the years ended December 31, 2018, 2017 and 2016, the income tax expense recorded differs from the result of applying the legal rate to the Company’s profit before income tax, as detailed below:

	2018			2017			2016
	US$(000)			US$(000)			US$(000)

Profit before income tax		444,880			835,924			603,989
Income tax rate		32	%		32	%		32	%
Expected income tax expense		142,362			267,496			193,276
Non - deductible expenses		25,352			25,217			27,788
Royalty case		143,728			(12,029	)		-
Special mining tax and mining royalties		(25,165	)		(21,704	)		(12,084	)
Special mining burden (GEM)		(22,334	)		-			-
Income tax rate change effect on deferred taxes for change in Peruvian tax law once the current Stability Contract expires (from 32% to 31.18%)		(1,958	)		(1,632	)		13,850
Income tax true – ups		(10,312	)		10,210			1,677
Others		4,896			(4,125	)		(1,913	)
Current and deferred income tax charges to results		256,569			263,433			222,594
Mining taxes charged to results		65,055			213,280			37,763
Supplementary retirement fund charged to results		3,546			9,330			2,725

		325,170			486,043			263,082

Effective income tax		73.09	%		58.14	%		43.56	%