Goodwill - Disclosure of detailed information about key assumptions for the CGU's (Details) - $ / ounce	Dec. 31, 2019	Dec. 31, 2018
Statements Line Items
Post-tax real discount rate	4.10%	5.10%
Long-term gold price [Member]
Statements Line Items
Gold price per ounce	1,400	1,300
Long-term silver price [Member]
Statements Line Items
Silver price per ounce	18	18

The discount rate applied to cash flow projections for a cash-generating unit (group of units). [Refer: Cash-generating units [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
-Paragraph 134
-Subparagraph d
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_v&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
-Paragraph 134
-Subparagraph e
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_v&doctype=Standard
-URIDate 2018-03-16

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Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant