Shareholder remuneration system and earnings per share - Schedule of diluted earnings per share (Details) - EUR (€) € / shares in Units, € in Millions	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024
Diluted earnings per share [abstract]
Profit attributable to the Parent (EUR million)	€ 6,833	€ 6,059
Remuneration of contingently convertible preferred securities (CCPS) (EUR million)	(310)	(309)
Net profit for the year	6,523	5,750
Profit or Loss from discontinued operations (non controlling interest net) (EUR million)	726	575
Profit or Loss from continuing operations (CCPS net) (EUR million)	€ 5,797	€ 5,175
Weighted average number of shares outstanding (in shares)	14,995,834,683	15,664,707,190
Dilutive effect of options/receipt of shares (in shares)	81,043,722	70,622,287
Adjusted number of shares (in shares)	15,076,878,405	15,735,329,477
Diluted earnings per share (in euro per share)	€ 0.43	€ 0.37
Diluted earnings per share from discontinued operations (in euro per share)	0.05	0.04
Diluted earnings per share from continuing operations (in euro per share)	€ 0.38	€ 0.33

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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Diluted earnings (loss) per share from continuing operations. [Refer: Continuing operations, unless line item indicates otherwise [member]; Diluted earnings (loss) per share]

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Diluted earnings (loss) per share from discontinued operations. [Refer: Diluted earnings (loss) per share; Discontinued operations [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 profit (loss) from continuing and discontinued operations attributable to owners of the parent. [Refer: Profit (loss)]

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The profit (loss) from continuing operations attributable to ordinary equity holders of the parent entity, adjusted for the effects of all dilutive potential ordinary shares. [Refer: Profit (loss) from continuing operations]

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The profit (loss) from discontinued operations attributable to ordinary equity holders of the parent entity, adjusted for the effects of all dilutive potential ordinary shares. [Refer: Profit (loss) from discontinued operations]

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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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The number of dilutive potential ordinary shares that relate to the assumed exercise of the entity's share options and the effect of share rights.

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