Derivative financial instruments and hedge accounting - Additional Information (Details) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Derivative financial instruments and hedge accounting
Derivative financial assets	€ 2,470	€ 6,264
Fair value hedges \| US Dollars
Derivative financial instruments and hedge accounting
Exchange rate risk deriving from securities	2,077
Positive (negative) exchange differences from the exposure to the exchange rate risk deriving from securities	(133)
Bonds issued	2,273
Cash flow hedges \| Sustainability
Derivative financial instruments and hedge accounting
Derivative financial assets	€ 1

Disclosure of derivative financial instruments

No definition available.

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- Definition

The amount of exchange rate risk deriving from securities.

+ References

No definition available.

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- Definition

The amount of bonds issued by the entity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The amount of financial assets classified as derivative instruments. [Refer: Financial assets; Derivatives [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The increase (decrease) in exposure to credit risk on loan commitments and financial guarantee contracts resulting from foreign exchange. [Refer: Exposure to credit risk on loan commitments and financial guarantee contracts]

+ References

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