Financial assets at fair value through profit or loss - Additional information (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
Disclosure of financial assets [line items]
Designated at fair value through profit or loss	€ 3,448	€ 5,740
Financial assets at fair value through profit or loss
Disclosure of financial assets [line items]
Gains (losses) on financial assets at fair value through profit or loss, designated upon initial recognition or subsequently	(177)	5
Notional value of related credit derivatives	2,486	3,807
Financial assets at fair value through profit or loss \| Credit risk
Disclosure of financial assets [line items]
Designated at fair value through profit or loss	2,454	3,797
Amount of change in fair value of the credit derivatives attributable to changes in credit risks	85	173
Cumulative change in fair value of changes in credit risk	513	489
Change for current year	23
Change in fair value of the credit derivatives for the current year	(88)	24
Financial assets at fair value through profit or loss \| - Derivatives
Disclosure of financial assets [line items]
Amount of change in fair value of the credit derivatives attributable to changes in credit risks	(85)	(214)
Change in fair value of the credit derivatives for the current year	€ 128	€ (95)

The accumulated increase (decrease) in the fair value of financial assets designated as measured at fair value through profit or loss that is attributable to changes in the credit risk of the assets determined either: (a) as the amount of change in their fair value that is not attributable to changes in market conditions that gave rise to market risk; or (b) using an alternative method that the entity believes more faithfully represents the amount of change in its fair value that is attributable to changes in the credit risk of the asset. [Refer: Credit risk [member]; Market risk [member]; Increase (decrease) in fair value of financial assets designated as measured at fair value through profit or loss, attributable to changes in credit risk of financial assets]

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The accumulated increase (decrease) in fair value of credit derivatives or similar instruments related to financial assets designated as measured at fair value through profit or loss. [Refer: Derivatives [member]; Increase (decrease) in fair value of financial assets designated as measured at fair value through profit or loss related credit derivatives or similar instruments; Financial assets]

+ References

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The increase (decrease) in the fair value of a financial asset (or group of financial assets) designated as measured at fair value through profit or loss that is attributable to changes in the credit risk of that asset determined either: (a) as the amount of change in its fair value that is not attributable to changes in market conditions that give rise to market risk ; or (b) using an alternative method the entity believes more faithfully represents the amount of change in its fair value that is attributable to changes in the credit risk of the asset. [Refer: Credit risk [member]; Financial assets]

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The increase (decrease) in the fair value of credit derivatives or similar instruments related to financial assets designated as measured at fair value through profit or loss. [Refer: Derivatives [member]; Financial assets]

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The nominal amount of a credit derivative. [Refer: Derivatives [member]]

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The amount of financial assets at fair value through profit or loss that were designated as such upon initial recognition or subsequently. [Refer: At fair value [member]; Financial assets at fair value through profit or loss]

+ References

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