Segment information - Summary of Operating Results by Geographical Areas (Details) - EUR (€) € in Millions |
12 Months Ended | ||||||
|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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| Disclosure of geographical areas [line items] | |||||||
| Turnover | € 50,503 | € 52,479 | [1] | € 51,680 | [1] | ||
| Non-current assets | 44,732 | 53,541 | 51,084 | ||||
| United Kingdom | |||||||
| Disclosure of geographical areas [line items] | |||||||
| Turnover | 2,226 | 2,202 | 2,106 | ||||
| Non-current assets | 3,575 | 3,830 | 3,567 | ||||
| United States of America | |||||||
| Disclosure of geographical areas [line items] | |||||||
| Turnover | 10,497 | 10,393 | 10,315 | ||||
| Non-current assets | 16,807 | 19,715 | 18,205 | ||||
| India | |||||||
| Disclosure of geographical areas [line items] | |||||||
| Turnover | 6,217 | 6,492 | 6,516 | ||||
| Non-current assets | 5,444 | 6,700 | 6,436 | ||||
| Others | |||||||
| Disclosure of geographical areas [line items] | |||||||
| Turnover | 31,563 | 33,392 | 32,743 | ||||
| Non-current assets | € 18,906 | € 23,296 | € 22,876 | ||||
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