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Identification and business activity (Tables) | 12 Months Ended
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Dec. 31, 2017
Disclosure of identification and business activity [Line Items] |
Disclosure Of Significant Investments In Subsidiarie [Text Block] | The consolidated financial statements include the financial statements of the following subsidiaries:
|  |  |  | Ownership |
|  | Country of incorporation and business |  | December 31, 2017 |  | December 31, 2016 |
|  |  |  | Direct |  | Indirect |  | Direct |  | Indirect |
|  |  |  | % |  | % |  | % |  | % |
Mining activities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Compañía Minera Condesa S.A. |  | Peru |  |  | 100.00 |  |  | - |  |  | 100.00 |  |  | - |
Compañía Minera Colquirrumi S.A. |  | Peru |  |  | 100.00 |  |  | - |  |  | 100.00 |  |  | - |
Sociedad Minera El Brocal S.A.A. (*) |  | Peru |  |  | 3.18 |  |  | 58.24 |  |  | 3.08 |  |  | 58.24 |
Inversiones Colquijirca S.A. (*) |  | Peru |  |  | 89.76 |  |  | 10.24 |  |  | 89.76 |  |  | 10.24 |
S.M.R.L. Chaupiloma Dos de Cajamarca |  | Peru |  |  | 20.00 |  |  | 40.00 |  |  | 20.00 |  |  | 40.00 |
Minera La Zanja S.R.L. |  | Peru |  |  | 53.06 |  |  | - |  |  | 53.06 |  |  | - |
Minera Julcani S.A. de C.V. |  | Mexico |  |  | 99.80 |  |  | 0.20 |  |  | 99.80 |  |  | 0.20 |
Compañía de Minas Buenaventura Chile Ltda. |  | Chile |  |  | 90.00 |  |  | 10.00 |  |  | 90.00 |  |  | 10.00 |
El Molle Verde S.A.C. |  | Peru |  |  | 99.98 |  |  | 0.02 |  |  | 99.98 |  |  | 0.02 |
Apu Coropuna S.R.L. |  | Peru |  |  | 70.00 |  |  | - |  |  | 70.00 |  |  | - |
Cerro Hablador S.A.C. |  | Peru |  |  | 99.00 |  |  | 1.00 |  |  | 99.00 |  |  | 1.00 |
Minera Azola S.A.C. |  | Peru |  |  | 99.00 |  |  | 1.00 |  |  | 99.00 |  |  | 1.00 |
Compañía Minera Nueva Italia S.A. |  | Peru |  |  | - |  |  | 93.36 |  |  | - |  |  | 93.36 |
Energy generation and transmission services: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Consorcio Energético de Huancavelica S.A. |  | Peru |  |  | 100.00 |  |  | - |  |  | 100.00 |  |  | - |
Empresa de Generación Huanza S.A. |  | Peru |  |  | - |  |  | 100.00 |  |  | - |  |  | 100.00 |
Empresa de Generación Huaura S.A.C. (**) |  | Peru |  |  | - |  |  | - |  |  | 0.01 |  |  | 99.99 |
Construction, engineering services and insurance brokerage: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Buenaventura Ingenieros S.A. |  | Peru |  |  | 100.00 |  |  | - |  |  | 100.00 |  |  | - |
Contacto Corredores de Seguros S.A. |  | Peru |  |  | 99.98 |  |  | 0.02 |  |  | 99.98 |  |  | 0.02 |
BISA Argentina S.A. (before Minera San Francisco S.A.) |  | Argentina |  |  | 56.42 |  |  | 43.58 |  |  | 56.42 |  |  | 43.58 |
Contacto Risk Consulting S.A. |  | Peru |  |  | - |  |  | 98.00 |  |  | - |  |  | 98.00 |
Industrial activities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Procesadora Industrial Río Seco S.A. |  | Peru |  |  | 100.00 |  |  | - |  |  | 100.00 |  |  | - |
| (*) | As of December 31, 2017 and 2016, the participation of the Company in the voting rights of El Brocal is 61.42 and 61.32 percent, respectively. Inversiones Colquijirca S.A. (hereafter “Colquijirca”), a Group’s subsidiary (99.99 percent as of December 31, 2017 and 2016), has an interest in El Brocal’s capital stock, through which the Group holds an indirect participation in El Brocal of 58.24 as of December 31, 2017 and 2016.
| (**) | On December 29, 2016, the Board of Directors’ and Shareholders’ Meetings of Consorcio Energético de Huancavelica S.A. and Empresa de Generación Huaura S.A.C. approved the merger between these subsidiaries whereby Consorcio Energético de Huancavelica S.A. absorbed Empresa de Generación Huaura S.A.C. This merger had not effects in the consolidated financial statements.
Disclosure of net cash flows used by the mining units with discontinued operations [Text Block] | The net cash flows used by the mining units with discontinued operations for the years 2017, 2016 and 2015, are presented below:
|  | 2017 |  | 2016 |  | 2015 |
|  | US$(000) |  | US$(000) |  | US$(000) |
Operating activities |  |  | (8) |  |  | (7) |  |  | (8) |
Investing activities |  |  | - |  |  | - |  |  | (6) |
Financing activities |  |  | - |  |  | - |  |  | - |
Net decrease in cash and cash equivalents during the year |  |  | (8) |  |  | (7) |  |  | (14) |
Disclosure of results of the discontinued operations mining units [Text Block] | The results of the discontinued operations mining units for the years 2017, 2016 and 2015 are presented below:
|  | 2017 |  | 2016 |  | 2015 |
|  | US$(000) |  | US$(000) |  | US$(000) |
Operating income |  |  |  |  |  |  |  |  |  |
Net sales |  |  | - |  |  | 1,149 |  |  | 22,740 |
Total income |  |  | - |  |  | 1,149 |  |  | 22,740 |
Operating costs |  |  |  |  |  |  |  |  |  |
Cost of sales, excluding depreciation and amortization |  |  | - |  |  | (4,842) |  |  | (19,540) |
Exploration |  |  | - |  |  | (3,777) |  |  | (1,847) |
Depreciation and amortization |  |  | - |  |  | (5,049) |  |  | (9,882) |
Mining royalties |  |  | - |  |  | (11) |  |  | (223) |
Total operating costs |  |  | - |  |  | (13,679) |  |  | (31,492) |
Gross loss |  |  | - |  |  | (12,530) |  |  | (8,752) |
Operating income (expenses), net |  |  |  |  |  |  |  |  |  |
Net loss in sale of mining units |  |  | (18,550) |  |  | (3,014) |  |  | - |
Changes in provision for closure of mining units, note 15(b) |  |  | (12,701) |  |  | (3,365) |  |  | (45) |
Administrative expenses |  |  | (941) |  |  | (111) |  |  | (2,234) |
Reversal (provision) for contingencies |  |  | (423) |  |  | 901 |  |  | (381) |
Gain (loss) for sale in other assets |  |  | (162) |  |  | 3,200 |  |  | - |
Reversal of Impairment loss of long-lived assets for sale of mining units and other assets, note 11(a) |  |  | 17,197 |  |  | - |  |  | - |
Reversal of provision for closure of mining units for sale of mining units, note 15(b) |  |  | 11,700 |  |  | - |  |  | - |
Reversal of provision for impairment of inventories, note 8(b) |  |  | 1,345 |  |  | 706 |  |  | 1,474 |
Impairment loss of long-lived assets, note 11(b) |  |  | - |  |  | (2,043) |  |  | (7,452) |
Other, net |  |  | (6,871) |  |  | (1,793) |  |  | (2,079) |
Total operating expenses, net |  |  | (9,406) |  |  | (5,519) |  |  | (10,717) |
Operating loss |  |  | (9,406) |  |  | (18,049) |  |  | (19,469) |
Other income (expense), net |  |  |  |  |  |  |  |  |  |
Finance costs, note 15(b) |  |  | (694) |  |  | (970) |  |  | (890) |
Net gain (loss) from currency exchange difference |  |  | 2 |  |  | (50) |  |  | 129 |
Total other expenses, net |  |  | (692) |  |  | (1,020) |  |  | (761) |
Loss before income tax |  |  | (10,098) |  |  | (19,069) |  |  | (20,230) |
Income tax |  |  | - |  |  | (4) |  |  | (3) |
Loss from discontinued operations |  |  | (10,098) |  |  | (19,073) |  |  | (20,233) |
Loss from the discontinued operations, per basic and diluted share, express in U. S. dollars |  |  | (0.04) |  |  | (0.07) |  |  | (0.08) |

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