Cost of sales (Tables)

12 Months Ended

Dec. 31, 2018

Sociedad Minera Cerro Verde S.A.A. [Member]

Disclosure of cost of sales [Line Items]

Disclosure Of Detailed Information About Cost Of Sales [Text block]

This item is made up as follows:

	For the year ended December 31, 2018			For the year ended December 31, 2017		For the year ended December 31, 2016
	US$(000)			US$(000)		US$(000)

Materials and supplies		693,316			556,022		496,918
Depreciation and amortization		512,298			456,467		472,997
Labor (a)		357,692			286,058		215,839
Energy		254,243			229,272		229,035
Third parties services		159,514			144,829		100,897
Management Fees		2,743			2,867		2,793
Change in work in process inventory		(8,513	)		51,412		(3,789	)
Change in finished goods inventory		(5,723	)		2,060		(3,951	)
Other costs		45,402			39,251		42,301

		2,010,972			1,768,238		1,553,040

(a)

Labor includes an expense of US$60.2 million related to profit sharing for the year ended December 31, 2018 (US$86.4 million for the year ended December 31, 2017

and US$36.8 million for the year ended December 31, 2016).

Additionally, it includes an expense of US$69.0 million related to the Union Agreement bonus payment obtained by workers as part of the new collective labor agreement, which is effective from September 1, 2018, through August 31, 2021.