Disclosure Of Sustainability-Related Financial Information
| Concept | 
                                    
                                        2023-04-01 to 2024-03-31  | 
                            
                                
                                    
                                        2022-04-01 to 2023-03-31  | 
                            
                                
                                    
                                        2018-04-01 to 2019-03-31  | 
                            
                        
|---|---|---|---|
| Disclosure of Sustainability-related Financial Information | |||
| Scope 1 and 2 greenhouse gas emissions | |||
| Gross scope 1 greenhouse gas emissions | 
                                        
                                             
                                                398
                                                
                                                    
                                                        utr:tCO2e
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                358
                                                
                                                    
                                                        utr:tCO2e
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                370
                                                
                                                    
                                                        utr:tCO2e
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Gross scope 2 greenhouse gas emissions | 
                                        
                                             
                                                903
                                                
                                                    
                                                        utr:tCO2e
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,187
                                                
                                                    
                                                        utr:tCO2e
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,399
                                                
                                                    
                                                        utr:tCO2e
                                                    
                                                
                                             
                                        
                                     |