v3.26.1
Capital and financial risk management - Market risk - Foreign exchange risk management - General information (Details) - EUR (€)
€ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Investments accounted for using equity method € 6,492 € 6,892
Currency risk [member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Net debt denominated in currencies other than euro (as a percent) 11.00%  
Minimum foreign exchange transaction exposure per currency per month period € 5  
Minimum foreign exchange transaction exposure per currency over six month period € 15  
Percentage of reasonably possible decrease in risk assumption 10.00%  
Currency risk [member] | South African rand    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Net debt denominated in currencies other than euro (as a percent) (8.00%)  
Decrease in equity due to sensitivity to foreign exchange movements € 112 131
Increase in equity due to sensitivity to foreign exchange movements € 91 107
Percentage of reasonably possible increase in risk assumption 10.00%  
Currency risk [member] | Other currencies    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Net debt denominated in currencies other than euro (as a percent) 3.00%  
Currency risk [member] | United States of America, Dollars    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Decrease in equity due to sensitivity to foreign exchange movements € 192 304
Increase in equity due to sensitivity to foreign exchange movements € 235 € 372
Percentage of reasonably possible increase in risk assumption 10.00%  
Percentage of reasonably possible decrease in risk assumption 10.00%  
Equity Risk [Member]    
Disclosure of nature and extent of risks arising from financial instruments [line items]    
Percentage Of Change In Share Price 10.00%  
Investments accounted for using equity method € 105