Pensions and other post-employment benefits - Defined benefit obligation funding arrangements (Details) - EUR (€) € in Millions	Dec. 31, 2025	Dec. 31, 2024
Actuarial assumptions analysis
Defined benefit obligation	€ 13,793	€ 15,789
Wholly funded
Actuarial assumptions analysis
Defined benefit obligation	10,834	12,665
Partly funded
Actuarial assumptions analysis
Defined benefit obligation	2,142	2,252
Unfunded
Actuarial assumptions analysis
Defined benefit obligation	€ 817	€ 872

The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2025-01-01
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2025-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2025-03-27

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