Dividends - Commentary (Details) - USD ($)		6 Months Ended
Mar. 31, 2020	Dec. 31, 2020
Ordinary shares
Disclosure of classes of share capital [line items]
Cancellation of dividends declared (in usd per share)	$ 0.21
Fourth quarter dividend
Disclosure of classes of share capital [line items]
Dividends proposed or declared before financial statements authorised for issue but not recognised as distribution to owners		$ 0

The amount of dividends proposed or declared after the reporting period but before financial statements are authorised for issue. Such dividends are not recognised as a liability at the end of the reporting period because no obligation exists at that time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 137
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_137_a&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 10
-IssueDate 2019-01-01
-Paragraph 13
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=10&code=ifrs-tx-2019-en-r&anchor=para_13&doctype=Standard
-URIDate 2019-03-27

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration