Goodwill and impairment test (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disclosure of information for cash-generating units [line items]
Impairment loss recognised in profit or loss, intangible assets and goodwill	€ 0	€ 0	€ 0
Goodwill	€ 18,419	€ 18,419	€ 18,419
Discount rate (WACC)	10.00%	11.50%	15.00%
Wittycel SAS
Disclosure of information for cash-generating units [line items]
Impairment loss recognised in profit or loss, intangible assets and goodwill				€ 13,632
Impairment loss recognised in profit or loss, goodwill				13,586
Impairment loss recognised in profit or loss, intangible assets other than goodwill	€ 0	€ 0	€ 0	€ 45
Splicos SAS
Disclosure of information for cash-generating units [line items]
Goodwill	€ 18,419	€ 18,419	€ 18,419

The discount rate applied to cash flow projections for a cash-generating unit (group of units). [Refer: Total for all cash-generating units [member]]

The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Total for all business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2025-01-01
-Paragraph 134
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_134_a&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2025-01-01
-Paragraph 135
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=36&code=ifrs-tx-2025-en-r&anchor=para_135_a&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2025-01-01
-Paragraph B67
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2025-en-r&anchor=para_B67_d&doctype=Appendix&subtype=B
-URIDate 2025-03-27

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 254
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_254_a&doctype=Standard
-URIDate 2025-03-27

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 255
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_255_a&doctype=Standard
-URIDate 2025-03-27

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 254
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_254_a&doctype=Standard
-URIDate 2025-03-27

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 255
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_255_a&doctype=Standard
-URIDate 2025-03-27

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 37
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_37&doctype=Standard
-URIDate 2025-03-27

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 37
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_37&doctype=Standard
-URIDate 2025-03-27

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 54
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_54_c&doctype=Standard
-URIDate 2025-03-27

+ Details