Financial assets and liabilities - Narrative (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Private Venture Fund \| Level 3
Fair value of financial instruments
Gains (losses) recognised in profit or loss including exchange differences, fair value measurement, assets	€ (42)	€ 23

The gains (losses) including exchange differences recognised in profit or loss on the fair value measurement of assets. [Refer: At fair value [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2023-01-01
-Paragraph 93
-Subparagraph e
-Clause i
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=13&code=ifrs-tx-2023-en-r&anchor=para_93_e_i&doctype=Standard
-URIDate 2023-03-23

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration