Shareholder remuneration system and earnings per share - EPS Basic (Details) - EUR (€) € / shares in Units, € in Millions	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Basic earnings per share [abstract]
Profit attributable to the parent	€ (10,798)	€ 3,231
Remuneration of contingently convertible preference shares (CCP) (million euros)	(278)	(298)
Net profit for the year	(11,076)	2,933
Profit or Loss from discontinued operations (non-controlling interest net) (million euros)	0	0
Profit or Loss from continuing operations (net of non-controlling interests and CCP) (million euros)	€ (11,076)	€ 2,933
Weighted average number of shares outstanding (in shares)	16,598,649,355	16,231,374,256
Total basic earnings (loss) per share (eur per share)	€ (0.67)	€ 0.18
Basic earnings per share from discontinued operations (eur per share)	0	0
Basic earnings per share from continuing operations (eur per share)	€ (0.67)	€ 0.18

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).

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Basic earnings (loss) per share from continuing operations. [Refer: Basic earnings (loss) per share; Continuing operations [member]]

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Basic earnings (loss) per share from discontinued operations. [Refer: Basic earnings (loss) per share; Discontinued operations [member]]

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The increase (decrease) in equity resulting from the conversion of convertible instruments.

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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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