Impairment of intangible assets (Details) - EUR (€) € in Millions |
6 Months Ended | |
|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Disclosure of impairment loss and reversal of impairment loss [abstract] | ||
| Impairment loss on other intangible assets | € 1,031 | € 210 |
| Disclosure of impairment loss and reversal of impairment loss [line items] | ||
| Impairment loss on other intangible assets | 1,031 | € 210 |
| Amlitelimab asset | ||
| Disclosure of impairment loss and reversal of impairment loss [abstract] | ||
| Impairment loss on other intangible assets | 952 | |
| Disclosure of impairment loss and reversal of impairment loss [line items] | ||
| Impairment loss on other intangible assets | € 952 | |