v3.26.1
Income (expense) from investments - Additional information (Details) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Other gain (loss) from investments      
Dividend income € 242 € 227 € 255
Capital gain realized from the sale of investments 77 562 430
Capital gain from the fair value measurement of the residual stake of investments held 27 118 414
Nigeria LNG Ltd      
Other gain (loss) from investments      
Dividend income 156 166 179
Saudi European Petrochemical Co      
Other gain (loss) from investments      
Dividend income 21 22 € 55
Eni CCUS Holding      
Other gain (loss) from investments      
Capital gain realized from the sale of investments 46    
Capital gains from the fair value measurement of the business combination € 27    
Eni CCUS Holding | Global Infrastructure Partners (GIP)      
Other gain (loss) from investments      
Equity interest disposed (as a percent) 49.99%    
Ithaca Energy Plc      
Other gain (loss) from investments      
Capital gain realized from the sale of investments € 32    
Equity interest disposed (as a percent) 1.27%    
Capital gains from the fair value measurement of the business combination   118  
E&E Algeria Touat BV      
Other gain (loss) from investments      
Capital gains from the fair value measurement of the business combination € 86    
Nigerian Agip Oil Company Ltd. [member]      
Other gain (loss) from investments      
Capital gain realized from the sale of investments   € 371  
Nigerian Agip Oil Company Ltd. [member] | Oando PLC      
Other gain (loss) from investments      
Equity interest disposed (as a percent)   100.00%  
Saipem SpA      
Other gain (loss) from investments      
Capital gain realized from the sale of investments   € 166  
Equity interest disposed (as a percent)   10.00%  
Effects recognized in other comprehensive income   € 9  
SeaCorridor Srl | Snam Group [Member]      
Other gain (loss) from investments      
Equity interest disposed (as a percent)     49.90%