Disclosure Of Events After Reporting Period [Text Block]
| Concept | 
                                    
                                        2024-04-01 to 2025-03-31  | 
                            
                                
                                    
                                        2023-04-01 to 2024-03-31  | 
                            
                        
|---|---|---|
| Disclosure of events after reporting period [text block] | 
                                        
                                             | 
                                
                                    — | 
| Dividends proposed or declared before financial statements authorised for issue but not recognised as distribution to owners | 
                                        
                                             
                                                87,300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                81,500,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             
                                        
                                     |