Mineral Property, Pland and Equipment (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about property, plant and equipment [line items]
Construction in progress	$ 120.7	$ 64.4

The amount of expenditure capitalised during the construction of non-current assets that are not yet available for use. [Refer: Non-current assets]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 16
-IssueDate 2018-01-01
-Paragraph 37
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=16&date=2018-03-01&anchor=para_37&doctype=Standard
-URIDate 2018-03-16

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