Basis of preparation - Government grants (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Corporate information and statement of IFRS compliance [abstract]
Income from government grants	€ 2,634	€ 1,716	€ 1,665
Government grants	€ 220	€ 219

The amount of assistance by government in the form of transfers of resources to an entity in return for past or future compliance with certain conditions relating to the operating activities of the entity, recognised as deferred income. They exclude those forms of government assistance that cannot reasonably have a value placed upon them and transactions with government that cannot be distinguished from the normal trading transactions of the entity. [Refer: Deferred income other than contract liabilities; Government [member]]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_55&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_GovernmentGrants
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant