Pensions and other post-employment benefits - Defined benefit obligation funding arrangements (Details) - EUR (€) € in Millions	Dec. 31, 2023	Dec. 31, 2022
Actuarial assumptions analysis
Defined benefit obligation	€ 16,868	€ 18,312
Wholly funded
Actuarial assumptions analysis
Defined benefit obligation	12,782	14,330
Partly funded
Actuarial assumptions analysis
Defined benefit obligation	3,149	3,009
Unfunded
Actuarial assumptions analysis
Defined benefit obligation	€ 937	€ 973

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 2023-01-01
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2023-03-23

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