Dividends - Narrative (Details)	12 Months Ended
Dec. 31, 2018 $ / shares
Ordinary Shares
Disclosure of classes of share capital [line items]
Quarterly dividend paid per ordinary share (in USD per share)	$ 0.1025
American Depositary Share
Disclosure of classes of share capital [line items]
Quarterly dividend paid per ordinary share (in USD per share)	$ 0.615

The amount, per share, of dividends proposed or declared before financial statements were authorised for issue but not recognised as distribution to owners.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 137
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_137_a&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_DividendsProposedOrDeclaredBeforeFinancialStatementsAuthorisedForIssueButNotRecognisedAsDistributionToOwnersPerShare
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration