Cash and cash equivalents - Narrative (Details) - EUR (€) € in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Disclosure Of Cash And Cash Equivalents [Line Items]
Notice accounts	€ 26,915		€ 44,239
Effect of movements in exchange rates on cash held	(700)	€ 1,319
United States of America, Dollars
Disclosure Of Cash And Cash Equivalents [Line Items]
Effect of movements in exchange rates on cash held	€ 447		€ 2,035

The effect of exchange rate changes on cash and cash equivalents held or due in a foreign currency. [Refer: Cash and cash equivalents]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 25
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_25&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 28
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_28&doctype=Standard
-URIDate 2024-03-27

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