Staff costs - Schedule of deferred variable remuneration systems, deferred multiyear objectives variable remuneration plan (Details) € in Millions	12 Months Ended
Dec. 31, 2025 EUR (€) trading_session companies
Share-based payment arrangement
Deferral period	5 years
Immediate payment percentage	40.00%
Deferred payment percentage	60.00%
Deferred variable compensation plan linked to multiannual objectives
Share-based payment arrangement
Deferral period	5 years
Deferred payment, percentage paid in shares	60.00%
Number of trading sessions \| trading_session	15
Deferred payment percentage	60.00%
Deferred variable compensation plan linked to multiannual objectives \| Minimum
Share-based payment arrangement
Deferral period	3 years
Deferred variable compensation plan linked to multiannual objectives \| Maximum
Share-based payment arrangement
Deferral period	5 years
Deferred variable remuneration, three-year plan \| Minimum
Share-based payment arrangement
Deferral period	3 years
Deferred variable remuneration, four-year plan
Share-based payment arrangement
Deferral period	4 years
Deferred variable remuneration, five-year plan \| Maximum
Share-based payment arrangement
Deferral period	5 years
Deferred multiyear objectives variable remuneration plan seventh cycle
Share-based payment arrangement
Number of credit institutions included in reference group \| companies	9
Deferred multiyear objectives variable remuneration plan seventh cycle \| Minimum
Share-based payment arrangement
Deferral period	4 years
Deferred multiyear objectives variable remuneration plan seventh cycle \| Maximum
Share-based payment arrangement
Deferral period	5 years
Deferred multiyear objectives variable remuneration plan seventh cycle \| Executive directors
Share-based payment arrangement
Deferred payment, percentage paid in share options	25.00%
Deferred payment, percentage paid in shares	25.00%
Deferred multiyear objectives variable remuneration plan first cycle \| Executive directors and members of identified staff with total variable remuneration specified amount
Share-based payment arrangement
Deferral period	5 years
Gross variable remuneration benchmark threshold \| €	€ 2.7
Immediate payment percentage	40.00%
Deferred payment percentage	60.00%
Deferred multiyear objectives variable remuneration plan first cycle \| Senior managers, country heads, other executives and identified staff with total variable remuneration specified amount
Share-based payment arrangement
Deferral period	5 years
Immediate payment percentage	50.00%
Deferred payment percentage	50.00%
Percentage of entity economic capital	1.00%
Deferred multiyear objectives variable remuneration plan first cycle \| Senior managers, country heads, other executives and identified staff with total variable remuneration specified amount \| Minimum
Share-based payment arrangement
Gross variable remuneration benchmark threshold \| €	€ 1.7
Deferred multiyear objectives variable remuneration plan first cycle \| Senior managers, country heads, other executives and identified staff with total variable remuneration specified amount \| Maximum
Share-based payment arrangement
Gross variable remuneration benchmark threshold \| €	€ 2.7
Deferred multiyear objectives variable remuneration plan first cycle \| Other beneficiaries
Share-based payment arrangement
Deferral period	3 years
Immediate payment percentage	60.00%
Deferred payment percentage	40.00%
Deferred multiyear objectives variable remuneration plan second and third cycles
Share-based payment arrangement
Number of credit institutions included in reference group \| companies	17
Deferred multiyear objectives variable remuneration plan fourth cycle
Share-based payment arrangement
Number of credit institutions included in reference group \| companies	9

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

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+ Details

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- Definition

The threshold trigger amount of variable remuneration or bonus, in which will be deferred over a specified period and paid in shares.

+ References

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- Definition

Number of credit institutions included in reference group.

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- Definition

Represents the country heads of countries that are a percentage of the entity's economic capital.

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- Definition

The deferral period to pay variable remuneration or bonus.

+ References

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- Definition

Variable Remuneration, Deferred Payment, Percentage Paid In Share Options

+ References

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- Definition

The percentage of an award granted under a variable remuneration deferred payment plan paid in shares.

+ References

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- Definition

The percentage of variable remuneration with deferred payment during the period.

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- Definition

The percentage of variable remuneration with immediate payment during the period.

+ References

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- Definition

The number of trading sessions used in calculation of volume-weighted average share prices.

+ References

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