Bank loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Bank Loans [Abstract]
Beginning balance	$ 96,215	$ 55,000	$ 285,302
New loans	95,000	341,215	200,500
Disbursements	(95,000)	(300,000)	(442,957)
Sale of subsidiary	(1,215)	0	0
Exchange difference	0	0	12,155
Final balance	$ 95,000	$ 96,215	$ 55,000

The amount of current loans received and the current portion of non-current loans received. [Refer: Loans received]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_CurrentLoansReceivedAndCurrentPortionOfNoncurrentLoansReceived
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant