Staff costs and Directors' remuneration - Summary of Director's Emoluments (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Director [member]
Disclosure of Directors Emoluments [Line Items]
Base salaries, fees, performance payments and benefits	$ 6.9	$ 7.9	$ 8.4

The amount of remuneration paid or payable to the entity's directors.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

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