Contingent liabilities and legal proceedings - Tax (Details) $ in Millions	Dec. 31, 2025 USD ($)
Brazil \| Maximum \| Tax contingent liability
Disclosure of contingent liabilities [line items]
Potential liability	$ 951
India
Disclosure of contingent liabilities [line items]
Receivable for protest payments	115
Receivable for protest payments, corporate taxes	103
Receivable for protest payments, indirect taxes	12
India \| Maximum \| Tax contingent liability
Disclosure of contingent liabilities [line items]
Potential liability	$ 89

The amount of the estimated financial effect of contingent liabilities. [Refer: Classes of contingent liabilities [domain]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2025-01-01
-Paragraph 86
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_86_a&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 259
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_259_a&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 259
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_259_a&doctype=Standard
-URIDate 2025-03-27

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