Related party disclosures - Summary of Total Compensation of Key Management Personnel (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Compensation of key management personnel [abstract]
Short-term employment benefits	$ 20.1	$ 18.6	$ 18.7
Contributions to defined contribution pension plans	0.4	0.5	0.5
Equity compensation benefits	16.4	15.8	13.4
Total compensation of key management personnel	$ 36.9	$ 34.9	$ 32.6

The amount of compensation to key management personnel. [Refer: Key management personnel of entity or parent [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
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-URIDate 2024-03-27

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- Definition

The amount of compensation to key management personnel in the form of post-employment benefits. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
-Paragraph 17
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- Definition

The amount of compensation to key management personnel in the form of share-based payments. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
-Paragraph 17
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- Definition

The amount of compensation to key management personnel in the form of short-term employee benefits. [Refer: Key management personnel of entity or parent [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 24
-IssueDate 2024-01-01
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-URIDate 2024-03-27

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- Definition

Compensation of key management personnel abstract.

+ References

No definition available.

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