Earnings/(loss) per share - Disclosure of reconciliation of diluted earnings per share (Details) - EUR (€) € / shares in Units, shares in Thousands, € in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Earnings per share [abstract]
Owners of the parent	€ (22,368)	€ 5,473	€ 18,596
Weighted average number of shares outstanding for diluted earnings per share (in shares)	2,886,684	2,975,820	3,132,458
Weighted average number of shares outstanding (in shares)	2,886,684	2,949,652	3,107,725
Number of shares deployable for share-based compensation (in shares)	0	26,168	24,733
Diluted earnings per share (in EUR per share)	€ (7.75)	€ 1.84	€ 5.94

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The profit (loss) attributable to ordinary equity holders of the parent entity. [Refer: Profit (loss)]

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The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

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