Related party disclosures - Summary of Related Party Disclosures for Associates and Joint Ventures (Detail) - Associates [member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disclosure of transactions between related parties [Line Items]
Fee revenue	$ 12	$ 11	$ 9
Amounts receivable (net)	$ 41	19	$ 10
Amounts payable		$ (10)

The amounts payable resulting from related party transactions. [Refer: Total for all related parties [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
-Paragraph 20
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=24&code=ifrs-tx-2024-en-r&anchor=para_20&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
-Paragraph 18
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=24&code=ifrs-tx-2024-en-r&anchor=para_18_b&doctype=Standard
-URIDate 2024-03-27

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	ifrs-full_
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Balance Type:	na
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- Definition

The amount of revenue arising from the rendering of services in related party transactions. [Refer: Revenue; Total for all related parties [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
-Paragraph 21
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=24&code=ifrs-tx-2024-en-r&anchor=para_21_c&doctype=Standard
-URIDate 2024-03-27

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Balance Type:	credit
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- Definition

The amount of receivables due from related parties. [Refer: Total for all related parties [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 78
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_78_b&doctype=Standard
-URIDate 2024-03-27

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Period Type:	instant

- Details

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Period Type: