v3.25.1
Borrowings - Bonds and Own shares (Details)
€ in Millions, ¥ in Billions, £ in Billions, kr in Billions, SFr in Billions, $ in Billions, $ in Billions, $ in Billions
12 Months Ended
Mar. 31, 2025
EUR (€)
shares
Mar. 31, 2025
USD ($)
shares
Mar. 31, 2025
GBP (£)
shares
Mar. 31, 2025
CHF (SFr)
shares
Mar. 31, 2025
HKD ($)
shares
Mar. 31, 2025
AUD ($)
shares
Mar. 31, 2025
NOK (kr)
shares
Mar. 31, 2024
EUR (€)
shares
Mar. 31, 2025
USD ($)
Mar. 31, 2025
GBP (£)
Mar. 31, 2025
CHF (SFr)
Mar. 31, 2025
HKD ($)
Mar. 31, 2025
AUD ($)
Mar. 31, 2025
JPY (¥)
Mar. 31, 2025
NOK (kr)
Liquidity and capital resources                              
Notional amount € 22,628             € 24,783              
Maximum [Member]                              
Liquidity and capital resources                              
Treasury shares | shares 2,305,697,477 2,305,697,477 2,305,697,477 2,305,697,477 2,305,697,477 2,305,697,477 2,305,697,477 1,825,624,610              
Percentage of issued share capital held as treasury shares 8.20% 8.20% 8.20% 8.20% 8.20% 8.20% 8.20% 6.30%              
Bonds                              
Liquidity and capital resources                              
Notional amount of borrowings outstanding € 35,500                            
Bonds | US Dollar                              
Liquidity and capital resources                              
Bonds issued | $                 $ 18.4            
Nominal values of bonds matured 900 $ 1.0                          
Nominal values of bonds re-purchased 3,100 $ 3.3                          
Bonds | Euro                              
Liquidity and capital resources                              
Bonds issued 13,000                            
Nominal values of bonds re-purchased 2,600                            
Bonds | Sterling                              
Liquidity and capital resources                              
Bonds issued | £                   £ 4.0          
Nominal values of bonds re-purchased 100   £ 0.1                        
Bonds | Australia, Dollars                              
Liquidity and capital resources                              
Bonds issued | $                         $ 0.3    
Nominal values of bonds re-purchased 100         $ 0.2                  
Bonds | Hong Kong, Dollars                              
Liquidity and capital resources                              
Bonds issued | $                       $ 1.8      
Nominal values of bonds re-purchased 40       $ 0.3                    
Bonds | Norway, Krone                              
Liquidity and capital resources                              
Bonds issued | kr                             kr 0.2
Nominal values of bonds re-purchased 200           kr 2.0                
Bonds | Switzerland, Francs                              
Liquidity and capital resources                              
Bonds issued | SFr                     SFr 0.2        
Nominal values of bonds matured 400     SFr 0.4                      
Nominal values of bonds re-purchased € 100     SFr 0.1                      
Bonds | Japan, Yen                              
Liquidity and capital resources                              
Bonds issued | ¥                           ¥ 10.0  
Bonds | Minimum.                              
Liquidity and capital resources                              
Borrowing interest rate 0.50%             0.375% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%
Bonds | Maximum [Member]                              
Liquidity and capital resources                              
Borrowing interest rate 8.00%             8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%
Euro medium-term note programme                              
Liquidity and capital resources                              
Number of note programmes 2 2 2 2 2 2 2                
Euro medium-term note programme | Euro                              
Liquidity and capital resources                              
Cash raised from bonds issued € 2,800                            
Euro medium-term note programme, one                              
Liquidity and capital resources                              
Notional amount 30,000                            
Euro medium-term note programme, one | Euro                              
Liquidity and capital resources                              
Cash raised from bonds issued 600                            
Euro medium-term note programme, two                              
Liquidity and capital resources                              
Notional amount € 30,000                            
Euro medium-term note programme, two | US Dollar                              
Liquidity and capital resources                              
Cash raised from bonds issued | $   $ 3.0