Transactions with associates companies - Additional information (Details) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Transactions with associates companies [Line Items]
LIBOR interest rate on accounts receivable	6.25%
Related parties [member]
Disclosure Of Transactions with associates companies [Line Items]
Amounts receivable, related party transactions	$ 31,000	$ 19,000
Minera Yanacocha S.R.L. [Member]
Disclosure Of Transactions with associates companies [Line Items]
Royalty percentage	3

The amounts receivable resulting from related party transactions. [Refer: Related parties [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2019-01-01
-Paragraph 20
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-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2019-01-01
-Paragraph 18
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=24&code=ifrs-tx-2019-en-r&anchor=para_18_b&doctype=Standard
-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant