Financial assets at fair value through profit or loss - Additional information (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Disclosure of financial assets [line items]
Designated at fair value through profit or loss	€ 5,740	€ 5,775
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	5	(48)
Notional value of related credit derivatives	3,807	3,679
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	3,797	3,181
Amount of change in fair value of the credit derivatives attributable to changes in credit risks	173	150
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	(214)	(119)
Change in fair value of the credit derivatives for the current year	€ (95)	€ (122)

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]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 9
-Subparagraph c
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-URIDate 2024-03-27

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- Definition

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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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 24G
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_24G_a&doctype=Standard
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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.

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No definition available.

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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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 8
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_8_a&doctype=Standard
-URIDate 2024-03-27

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The gains (losses) on financial assets at fair value through profit or loss that were designated as such upon initial recognition or subsequently. [Refer: Financial assets at fair value through profit or loss, designated upon initial recognition or subsequently; Gains (losses) on financial assets at fair value through profit or loss]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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