Tax on Profit/(Loss) for the Year and Deferred Tax - Additional Information (Detail) - EUR (€) € in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disclosure of temporary difference, unused tax losses and unused tax credits [line items] | |||
| Deferred tax assets, not recognized | € 721,631 | € 599,476 | € 537,953 |
| Tax losses carryforwards other temporary deductible differences amount | 3,280,000 | ||
| Tax losses carryforwards | 1,954,600 | 1,946,200 | 2,371,300 |
| Income taxes refund | 700 | 700 | 700 |
| Additional future tax deduction related to share based payments | € 67,000 | 21,700 | 10,600 |
| Future tax period | 20 years | ||
| Additional tax deductions related to tax credits | € 29,700 | € 24,800 | € 8,400 |
| Revenue threshold limit | € 750,000 | ||