Group employees - Additional Information (Details) - Employee	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Number and average number of employees [abstract]
Average number of employees	74,617	75,452

The average number of personnel employed by the entity during a period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2024-03-27

Name:	ifrs-full_AverageNumberOfEmployees
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration