v3.26.1
Derivative financial instruments and hedge accounting - Hedging derivative instruments (Details)
€ in Millions
12 Months Ended
Dec. 31, 2025
EUR (€)
Dec. 31, 2024
EUR (€)
Cash flow hedge derivatives    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 4,978 5,476
Change in fair value (effective hedge) € 632 € (1,035)
Change in fair value (ineffective hedge) € 3 € 26
Cash flow hedge derivatives | Commodity price risk    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 4,978 5,128
Change in fair value (effective hedge) € 632 € (1,023)
Change in fair value (ineffective hedge) € 3 € 26
Cash flow hedge derivatives | Commodity price risk | Over the counter contract    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 1,506 1,753
Change in fair value (effective hedge) € 448 € (524)
Change in fair value (ineffective hedge) € 2 € 13
Cash flow hedge derivatives | Commodity price risk | Futures contract    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 3,472 3,375
Change in fair value (effective hedge) € 184 € (499)
Change in fair value (ineffective hedge) € 1 € 13
Cash flow hedge derivatives | Other cash flow derivatives    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument   348
Change in fair value (effective hedge)   € (12)
Cash flow hedge derivatives | Other cash flow derivatives | Other contract    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument   348
Change in fair value (effective hedge)   € (12)
Fair value hedge derivatives    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 1,962 2,024
Change in fair value (effective hedge) € (4) € 44
Change in fair value (ineffective hedge)   € 1
Fair value hedge derivatives | Currency risk    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument   43
Change in fair value (effective hedge)   € 2
Fair value hedge derivatives | Currency risk | Outright    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument   43
Change in fair value (effective hedge)   € 2
Fair value hedge derivatives | Interest rate risk    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 1,962 1,981
Change in fair value (effective hedge) € (4) € 42
Change in fair value (ineffective hedge)   € 1
Fair value hedge derivatives | Interest rate risk | Interest rate swap contract    
Derivative financial instruments and hedge accounting    
Nominal amount of the hedging instrument 1,962 1,981
Change in fair value (effective hedge) € (4) € 42
Change in fair value (ineffective hedge)   € 1