The applicable income tax rate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 12
-IssueDate 2025-01-01
-Paragraph 81
-Subparagraph c
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2025-en-r&anchor=para_81_c_ii&doctype=Standard
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 194
-Subparagraph c
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_194_c_ii&doctype=Standard
-URIDate 2025-03-27

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph 194
-Subparagraph c
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_194_c_ii&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_ApplicableTaxRate
Namespace Prefix:	ifrs-full_
Data Type:	dtr-2022:percentItemType
Balance Type:	na
Period Type:	duration

Income tax / (expense) - Additional information (Details) € in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2026 EUR (€)	Dec. 31, 2026	Jun. 30, 2026 USD ($)	Dec. 31, 2025 EUR (€)	Dec. 31, 2025 USD ($)
Disclosure Of Income Tax [Line Items]
Unused tax losses with no expiration date	€ 592,434			€ 592,434
Unused tax losses subject to expiration	15,251		$ 17,377	€ 14,821	$ 17,415
Current tax expense (income)	€ 0
Forecast
Disclosure Of Income Tax [Line Items]
Applicable tax rate		0.00%