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v3.19.1

Provisions and contingent liabilities (Tables) | 12 Months Ended
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Dec. 31, 2018
Disclosure of provisions [Line Items] |
Disclosure of detailed information about provisions [Text Block] |
| (a) | This caption is made up as follows:
|  | 2018 |  |  | 2017 |
|  | US$(000) |  |  | US$(000) |
Provision for closure of mining units and exploration projects (b) |  |  | 225,877 |  |  |  | 200,183 |
Provision for bonus to employees and officers |  |  | 18,620 |  |  |  | 2,331 |
Provision for obligations with communities (c) |  |  | 5,878 |  |  |  | 19,376 |
Provision for safety contingencies |  |  | 4,877 |  |  |  | 3,898 |
Provision for labor contingencies |  |  | 4,042 |  |  |  | 2,963 |
Provision for environmental liabilities |  |  | 3,768 |  |  |  | 5,534 |
Board of Directors’ participation |  |  | 2,108 |  |  |  | 1,273 |
Workers’ profit sharing payable |  |  | 1,772 |  |  |  | 3,569 |
Provision for environmental contingencies |  |  | 234 |  |  |  | 1,233 |
Other provisions |  |  | 758 |  |  |  | 1,364 |
|  |  | 267,934 |  |  |  | 241,724 |
Classification by maturity: |  |  |  |  |  |  |  |
Current portion |  |  | 68,172 |  |  |  | 76,847 |
Non-current portion |  |  | 199,762 |  |  |  | 164,877 |
|  |  | 267,934 |  |  |  | 241,724 |
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:
|  | 2018 |  |  | 2017 |
|  | US$(000) |  |  | US$(000) |
Beginning balance |  |  | 200,183 |  |  |  | 206,462 |
Changes (additions and deductions) in estimates |  |  |  |  |  |  |  |
Continuing mining units, note 11(a) |  |  | 42,874 |  |  |  | 10,594 |
Discontinued mining units, note 1(e) |  |  | 6,013 |  |  |  | 12,701 |
Exploration projects, note 26(a) |  |  | (2,433 | ) |  |  | 891 |
Accretion expense: |  |  |  |  |  |  |  |
Continuing mining units, note 27(a) |  |  | 4,911 |  |  |  | 4,360 |
Exploration projects, note 27(a) |  |  | 71 |  |  |  | 22 |
Discontinued mining units, note 1(e) |  |  | 54 |  |  |  | 215 |
Disbursements |  |  | (25,796 | ) |  |  | (23,292 | )
Sale of mining units, note 1(e) |  |  | - |  |  |  | (11,770 | )
Final balance |  |  | 225,877 |  |  |  | 200,183 |
Classification by maturity: |  |  |  |  |  |  |  |
Current portion |  |  | 30,524 |  |  |  | 39,826 |
Non-current portion |  |  | 195,353 |  |  |  | 160,357 |
|  |  | 225,877 |  |  |  | 200,183 |
Minera Yanacocha SRL and subsidiary [member] |
Disclosure of provisions [Line Items] |
Disclosure of detailed information about provisions [Text Block] |
| (a) | This caption is made up as follows:
|  | 2018 |  |  | 2017 |
|  | US$(000) |  |  | US$(000) |
Provision for closure of mining units and exploration projects (b) |  |  | 1,294,464 |  |  |  | 1,234,731 |
Provision of social responsibility (c) |  |  | 18,010 |  |  |  | 21,689 |
Accrual of operating costs (d) |  |  | 11,442 |  |  |  | 15,064 |
Workers’ profit sharing payable (e) |  |  | 3,920 |  |  |  | 1,733 |
Accrual of capital expenditure |  |  | 3,682 |  |  |  | 1,840 |
Other provisions |  |  | 2,785 |  |  |  | 1,403 |
|  |  | 1,334,303 |  |  |  | 1,276,460 |
Classification by maturity: |  |  |  |  |  |  |  |
Current portion |  |  | 41,154 |  |  |  | 39,495 |
Non-current portion |  |  | 1,293,149 |  |  |  | 1,236,965 |
|  |  | 1,334,303 |  |  |  | 1,276,460 |
Disclosure of detailed information about provision for closure of mining units and exploration projects [Text Block] | The movement of the ARO for 2018, 2017 and 2016 is broken down as follows:
|  | 2018 |  |  | 2017 |  |  | 2016 |
|  | US$(000) |  |  | US$(000) |  |  | US$(000) |
Opening balance |  |  | 1,234,731 |  |  |  | 1,012,888 |  |  |  | 578,959 |
Additional provisions |  |  | 43,560 |  |  |  | 221,450 |  |  |  | 430,292 |
Payments |  |  | (19,842 | ) |  |  | (21,376 | ) |  |  | (10,467 | )
Unwinding of discount, note 20 |  |  | 36,015 |  |  |  | 21,769 |  |  |  | 14,104 |
Final balance |  |  | 1,294,464 |  |  |  | 1,234,731 |  |  |  | 1,012,888 |
Classification by maturity |  |  |  |  |  |  |  |  |  |  |  |
Current portion |  |  | 19,325 |  |  |  | 19,455 |  |  |  | 15,636 |
Non-current portion |  |  | 1,275,139 |  |  |  | 1,215,276 |  |  |  | 997,252 |
|  |  | 1,294,464 |  |  |  | 1,234,731 |  |  |  | 1,012,888 |
Sociedad Minera Cerro Verde S.A.A. [Member] |
Disclosure of provisions [Line Items] |
Disclosure of detailed information about provisions [Text Block] |
|  | December 31, 2018 |  |  | December 31, 2017 |
|  | US$(000) |  |  | US$(000) |
Current: |  |  |  |  |  |  |  |
Provisions related to services and freight not invoiced |  |  | 11,823 |  |  |  | 14,513 |
Provision for social commitments (a) |  |  | 1,815 |  |  |  | 2,767 |
Provision for legal contingencies |  |  | 1,719 |  |  |  | 1,232 |
Provision for remediation and mine closure (b) |  |  | - |  |  |  | 690 |
Total current |  |  | 15,357 |  |  |  | 19,202 |
Non–current: |  |  |  |  |  |  |  |
Provision for royalties and mining tax (c) |  |  | 191,299 |  |  |  | 133,376 |
Provision for remediation and mine closure (b) |  |  | 131,888 |  |  |  | 156,169 |
Other long-term liabilities (d) |  |  | 11,033 |  |  |  | 15,889 |
Provision for social commitments (a) |  |  | 8,111 |  |  |  | 8,229 |
Total non-current |  |  | 342,331 |  |  |  | 313,663 |
| (a) | The provision for social commitments as of December 31, 2018, is associated with an irrigation project in La Joya (US$4.5 million) and repaving Alata-Congata Road (US$5.4 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. The closure plans for its mine site was approved by Resolution No 302-2009 MEM-AAM and its modifications were approved by Resolution No 207-2012 MEM-AAM, Resolution No 186-2014 MEM-DGAAM and its last modification, Resolution No 032-2018 MEM-DGAAM. As of December 31, 2018, pursuant to legal requirements, the Company has issued a letter of credit to the Ministry of Energy and Mines totaling US$42.7 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.
As of December 31, 2018, the Company’s provision for remediation and mine closure was US$131.9 million (reflecting the future value of the provision for remediation and mine closure of US$374.4 million, discounted using an annual risk-free rate of 2.99%). As of December 31, 2017, the Company’s provision for remediation and mine closure was US$156.9 million (reflecting the future value of the provision for remediation and mine closure of US$374.4 million, discounted using an annual risk-free rate of 2.73%). As of December 31, 2016, the Company’s provision for remediation and mine closure was US $153.3 million (reflecting the future value of the provision for remediation and mine closure of US $368.8 million, discounted using an annual risk-free rate of 2.97%) The Company considers this liability sufficient to meet the current environmental protection laws approved by the Ministry of Energy and Mines (MEM). As of December 31, 2018, changes in estimates (US$32.0 million) are mainly due to changes in the escalation ratio.
| (c) | As of December 31, 2018, represents the non-current portion of net assets tax (ITAN) for the years 2010, 2011 and 2013 of US$19.6 million and interest and penalties of (i) disputed mining royalties for the period October 2011 through December 2013 of US$70.0 million, (ii) special mining tax for the year 2011 through the year 2013 of US$50.8 million, (iii) income tax related to disputed mining royalties for the year 2010 of US$41.1 million and (iv) ITAN for the years 2010, 2011 and 2013 of US$9.8 million.
As of December 31, 2017, represents the non-current portion of disputed mining royalties for the period January 2009 through September 2011 of US$113.8 million, ITAN for the years 2010, 2011 and 2013 of US$19.6 million.
| (d) | Primarily represents SUNAT assessments for prior years related to income and non-income tax contingencies in which the Company expects to obtain an unfavorable result of US$6.2 million as of December 31, 2018 (US$11.4 million as of December 31, 2017).
Disclosure of detailed information about provision for closure of mining units and exploration projects [Text Block] | The table below presents the changes in the provision for remediation and mine closure:
|  | 2018 |  |  | 2017 |  |  | 2016 |
|  | US$(000) |  |  | US$(000) |  |  | US$(000) |
Beginning balance |  |  | 156,859 |  |  |  | 153,313 |  |  |  | 161,270 |
Accretion expense |  |  | 4,322 |  |  |  | 4,595 |  |  |  | 4,391 |
Changes in estimates, Note 7 |  |  | (32,017 | ) |  |  | (3,710 | ) |  |  | (16,091 | )
Additions, Note 7 |  |  | 2,724 |  |  |  | 2,661 |  |  |  | 3,743 |
Final balance |  |  | 131,888 |  |  |  | 156,859 |  |  |  | 153,313 |

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