Principal group companies - Summary of subsidiaries (Parenthetical) (Details)	12 Months Ended
Jun. 30, 2025
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	100.00%
USL Benefit Trust
Disclosure of subsidiaries [line items]
Proportion of ownership interest in subsidiary	2.38%

The proportion of ownership interest in a subsidiary attributable to the entity. [Refer: Total for all subsidiaries [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2024-01-01
-Paragraph 17
-Subparagraph b
-Clause iii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2024-en-r&anchor=para_17_b_iii&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 27
-IssueDate 2024-01-01
-Paragraph 16
-Subparagraph b
-Clause iii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2024-en-r&anchor=para_16_b_iii&doctype=Standard
-URIDate 2024-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2024-01-01
-Paragraph 19B
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_19B_c&doctype=Standard
-URIDate 2024-03-27

Name:	ifrs-full_ProportionOfOwnershipInterestInSubsidiary
Namespace Prefix:	ifrs-full_
Data Type:	dtr-2022:percentItemType
Balance Type:	na
Period Type:	duration