Cash and cash equivalents and investment securities - Summary of Investments in Short-Term Debt Securities (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Disclosure of detailed information about borrowings [abstract]
Investment in unquoted companies	$ 134	$ 139
Investment in debt securities	27	29
Non-current investments	161	168
Investment in debt securities	306	221
Current investments	$ 306	$ 221

The amount of current financial assets at fair value through other comprehensive income. [Refer: Financial assets at fair value through other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2025-01-01
-Paragraph 8
-Subparagraph h
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_8_h&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 44
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44_e&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 44
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_44_e&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_CurrentFinancialAssetsAtFairValueThroughOtherComprehensiveIncome
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant