Derivative instruments - Derivative assets and liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Foreign exchange forward contracts
Derivative instruments [Line Items]
Derivative assets	$ (5.3)	$ 3.2
Derivative (liabilities)	0.1	(1.1)
Unsettled provisionally priced concentrate derivatives, and swap contracts
Derivative instruments [Line Items]
Derivative (liabilities)	$ 1.2	$ (0.3)

The amount of financial liabilities classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_55&doctype=Standard
-URIDate 2024-03-27

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