Principal joint ventures and associates - Additional Information (Details) - Minera Escondida Ltda	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Disclosure Of Joint Ventures And Associates [Line Items]
Proportion of ownership interest in joint venture (%)	30.00%	30.00%
BHP Billiton
Disclosure Of Joint Ventures And Associates [Line Items]
Proportion of ownership interest in joint venture (%)	57.50%

The proportion of ownership interest in a joint venture attributable to the entity. [Refer: Joint ventures [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2021-01-01
-Paragraph 17
-Subparagraph b
-Clause iii
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-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2021-01-01
-Paragraph 16
-Subparagraph b
-Clause iii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=27&code=ifrs-tx-2021-en-r&anchor=para_16_b_iii&doctype=Standard
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2021-01-01
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-Subparagraph a
-Clause iv
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Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration