Revenue from Contracts with Customers - Additional Information (Detail) - EUR (€) € in Thousands |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Disclosure of disaggregation of revenue from contracts with customers [line items] | |||
| Percentage of entity's revenue | 100.00% | 100.00% | |
| Revenue from sale of carbon credits | € 10,680 | € 3,403 | |
| Long-term pending allocation to revenue | 13,013 | 1,425 | |
| Short-term pending allocation to revenue | € 454 | € 1,201 | |
| Bottom of range [member] | |||
| Disclosure of disaggregation of revenue from contracts with customers [line items] | |||
| Percentage of entity's revenue | 10.00% | 10.00% | |
| No Customer [Member] | Bottom of range [member] | |||
| Disclosure of disaggregation of revenue from contracts with customers [line items] | |||
| Percentage of entity's revenue | 10.00% | 10.00% | |