Disclosure Of Financial Instruments [Text Block]
| Concept | 
                                    
                                        2022-01-01 to 2022-12-31  | 
                            
                                
                                    
                                        2021-01-01 to 2021-12-31  | 
                            
                        
|---|---|---|
| Disclosure of financial instruments [text block] | 
                                        
                                             
                                                19. Financial instruments
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Description of accounting policy for financial instruments [text block] | 
                                        
                                             
                                                Financial instruments
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Disclosure of financial assets [text block] | — | — | 
| Disclosure of financial assets [abstract] | ||
| Disclosure of financial assets [line items] | ||
| Impairment loss on financial assets | 
                                        
                                             
                                                27,890,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                24,163,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Disclosure of credit risk [text block] | 
                                        
                                             
                                                Credit risk
                                                
                                             
                                        
                                     | 
                                
                                    — |