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Provisions (Tables) | 12 Months Ended
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Dec. 31, 2017
Disclosure of provisions [Line Items] |
Disclosure of detailed information about provisions [Text Block] | (a)
This caption is made up as follows:
|  | 2017 |  | 2016 |
|  | US$(000) |  | US$(000) |
Provision for closure of mining units and exploration projects (b) |  |  | 200,183 |  |  | 206,462 |
Provision for obligations with communities (c) |  |  | 19,376 |  |  | 4,710 |
Provision for environmental liabilities |  |  | 5,534 |  |  | 7,324 |
Provision for safety contingencies |  |  | 3,898 |  |  | 2,807 |
Provision for labor contingencies |  |  | 2,963 |  |  | 3,395 |
Workers’ profit sharing payable |  |  | 3,569 |  |  | 8,398 |
Board of Directors’ participation |  |  | 1,273 |  |  | 1,140 |
Provision for environmental contingencies |  |  | 1,233 |  |  | 753 |
Other provisions |  |  | 3,695 |  |  | 1,703 |
|  |  | 241,724 |  |  | 236,692 |
Classification by maturity: |  |  |  |  |  |  |
Current portion |  |  | 76,847 |  |  | 62,502 |
Non-current portion |  |  | 164,877 |  |  | 174,190 |
|  |  | 241,724 |  |  | 236,692 |
| (b) | Provision for closure of mining units and exploration projects -
Disclosure of detailed information about provision for closure of mining units and exploration projects [Text Block] | (b)
Provision for closure of mining units and exploration projects -
The table below presents the movement of the provision for closure of mining units and exploration projects:
|  | 2017 |  | 2016 |
|  | US$(000) |  | US$(000) |
Beginning balance |  |  | 206,462 |  |  | 166,403 |
Transfer of units held for sale |  |  | - |  |  | 15,851 |
Sale of mining units, note 1(e) |  |  | (11,770) |  |  | - |
Changes and additions in estimates: |  |  |  |  |  |  |
Discontinued mining units, note 1(e) |  |  | 12,701 |  |  | 3,365 |
Continuing mining units, note 11(a) |  |  | 10,594 |  |  | 34,532 |
Exploration projects |  |  | 891 |  |  | - |
Accretion expense: |  |  |  |  |  |  |
Discontinued operations, note 1(e) |  |  | 215 |  |  | 970 |
Continuing mining units, note 26(a) |  |  | 4,382 |  |  | 4,116 |
Disbursements |  |  | (23,292) |  |  | (18,775) |
Final balance |  |  | 200,183 |  |  | 206,462 |
Classification by maturity: |  |  |  |  |  |  |
Current portion |  |  | 39,826 |  |  | 37,405 |
Non-current portion |  |  | 160,357 |  |  | 169,057 |
|  |  | 200,183 |  |  | 206,462 |
Minera Yanacocha SRL and subsidiary [member] |
Disclosure of provisions [Line Items] |
Disclosure of detailed information about provisions [Text Block] | This caption is made up as follows:
|  | 2017 |  | 2016 |
|  | US$(000) |  | US$(000) |
Provision for closure of mining units and exploration projects (b) |  |  | 1,234,731 |  |  | 1,012,888 |
Provision of social responsability |  |  | 21,689 |  |  | 24,335 |
Workers’ profit sharing payable (c) |  |  | 1,733 |  |  | 13,005 |
Accrual of operating costs |  |  | 15,064 |  |  | 19,650 |
Other provisions |  |  | 3,243 |  |  | 23,809 |
|  |  | 1,276,460 |  |  | 1,093,687 |
Classification by maturity: |  |  |  |  |  |  |
Current portion |  |  | 39,495 |  |  | 68,662 |
Non-current portion |  |  | 1,236,965 |  |  | 1,025,025 |
|  |  | 1,276,460 |  |  | 1,093,687 |
Disclosure of detailed information about provision for closure of mining units and exploration projects [Text Block] | The movement of the ARO for 2017, 2016 and 2015 is broken down as follows:
|  | 2017 |  | 2016 |  | 2015 |
|  | US$(000) |  | US$(000) |  | US$(000) |
Opening balance |  |  | 1,012,888 |  |  | 578,959 |  |  | 557,457 |
Additional provisions |  |  | 221,450 |  |  | 430,292 |  |  | 10,434 |
Payments |  |  | (21,376) |  |  | (10,467) |  |  | (11,007) |
Unwinding of discount, note 19 |  |  | 21,769 |  |  | 14,104 |  |  | 22,075 |
Final balance |  |  | 1,234,731 |  |  | 1,012,888 |  |  | 578,959 |
Classification by maturity |  |  |  |  |  |  |  |  |  |
Current portion |  |  | 19,455 |  |  | 15,636 |  |  | 6,698 |
Non-current portion |  |  | 1,215,276 |  |  | 997,252 |  |  | 572,261 |
|  |  | 1,234,731 |  |  | 1,012,888 |  |  | 578,959 |
Sociedad Minera Cerro Verde S.A.A. [Member] |
Disclosure of provisions [Line Items] |
Disclosure of detailed information about provisions [Text Block] | This item is made up as follows:
|  | December 31, |  | December 31, |
|  | 2017 |  | 2016 |
|  | US$(000) |  | US$(000) |
Current: |  |  |  |  |  |  |
Provisions related to services and freight not invoiced |  |  | 14,513 |  |  | 11,231 |
Provision for social commitments (a) |  |  | 2,767 |  |  | 11,722 |
Provision for legal contingencies |  |  | 1,232 |  |  | 1,505 |
Provision for remediation and mine closure (b) |  |  | 690 |  |  | - |
Total current |  |  | 19,202 |  |  | 24,458 |
Non–current: |  |  |  |  |  |  |
Provision for remediation and mine closure (b) |  |  | 156,169 |  |  | 153,313 |
Provision for royalties and mining tax (c) |  |  | 148,530 |  |  | - |
Provision for interest (d) |  |  | 18,270 |  |  | - |
Other long-term liabilities (e) |  |  | 15,889 |  |  | 7,249 |
Provision for social commitments (a) |  |  | 8,229 |  |  | 4,060 |
Total non-current |  |  | 347,087 |  |  | 164,622 |
| (a) | The provision for social commitments as of December 31, 2017, is associated with an irrigation project in La Joya (US$5.5 million) and repaving Alata-Congata Road (US$5.5 million).
| (b) | The Company’s mineral exploitation activities are subject to environmental protection standards. In order to comply with these standards, the Company has obtained the approval for the Environment Adequacy Program (PAMA) and for the Environmental Impact Studies (EIA), required for the operation of Cerro Verde’s production unit.
On October 14, 2003, Law N° 28090 was enacted, which regulates the commitments and procedures that entities involved in mining activities must follow in order to prepare, file and implement a mine site closing plan, as well as the respective environmental guarantees that assure compliance with the plan in accordance with protection, conservation and restoration of the environment. On August 15, 2005, the regulations regarding this law were approved. During 2006, in compliance with the mentioned law, the Company completed the closure plans for its mine site, and presented it to the Ministry of Energy and Mines. On October 5, 2009, the Ministry of Energy and Mines issued Resolution No 302-2009 MEM-AAA, approving the Company’s mine closure plan. As of December 31, 2017, pursuant to legal requirements, the Company has issued letters of credit to the Ministry of Energy and Mines totaling US$35.5 million to secure mine closure plans. The estimate of remediation and mine closure costs is based on studies prepared by independent consultants and based on current environmental regulations. This provision corresponds mainly to the activities to be performed in order to restore the areas affected by mining activities. The main tasks to be performed include ground removal, soil recovery, and dismantling of plant and equipment.
| (c) | Represents the non-current portion of disputed mining royalties for the period December 2006 through September 2011 of US$127.5 million, net asset tax (ITAN) for the years 2010, 2011 and 2013 of US$19.6 million, penalties of royalties for the period December 2006 to 2008 of US$1.4 million (see Note 18(a)).
| (d) | Represent the non-current portion of interest and interest on penalties associated with the installment program of mining royalties for the period December 2006 through the year 2008 (see Note 14(d)).
| (e) | Represents prior year SUNAT assessments related to income and non-income tax contingencies in which the Company expects to obtain an unfavorable result of US$11.4 million.
Disclosure of movement in provision for remediation and mine closure [Text Block] | The table below presents the changes in the provision for remediation and mine closure:
|  | 2017 |  | 2016 |
|  | US$(000) |  | US$(000) |
Beginning balance |  |  | 153,313 |  |  | 161,270 |
Accretion expense |  |  | 4,595 |  |  | 4,391 |
Changes in estimates, note 8 |  |  | (3,710) |  |  | (16,091) |
Additions, note 8 |  |  | 2,661 |  |  | 3,743 |
Final balance |  |  | 156,859 |  |  | 153,313 |

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