Inventories - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Inventories [Abstract]
Inventories recognized as expense	$ 68,145	$ 82,856

The amount of inventories recognised as an expense during the period. [Refer: Inventories]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 2
-IssueDate 2016-01-13
-Paragraph 36
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=2&date=2016-03-30&anchor=para_36_d&doctype=Standard
-URIDate 2016-03-31

Name:	ifrs-full_CostOfInventoriesRecognisedAsExpenseDuringPeriod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration