Disclosure Of First-Time Adoption [Text Block]
| Concept | 2023-12-31 to 2024-12-28 | 2023-12-31 to 2024-12-28 | As at 2024-12-28 | 2023-12-31 to 2024-12-28 | As at 2024-12-28 | As at 2024-12-28 | 2023-12-31 to 2024-12-28 | As at 2024-12-28 | As at 2023-12-30 | As at 2023-12-30 | 2023-01-01 to 2023-12-30 | As at 2023-12-30 | 2023-01-01 to 2023-12-30 | 2023-01-01 to 2023-12-30 | As at 2023-12-30 | 2023-01-01 to 2023-12-30 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Disclosure of first-time adoption [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of comparative information prepared under previous GAAP [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of comparative information prepared under previous GAAP [abstract] | ||||||||||||||||||||
| Disclosure of comparative information prepared under previous GAAP [line items] | ||||||||||||||||||||
| Equity | — | — | 
                                                9,900,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                37,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                27,400,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                7,800,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                27,400,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                35,500,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                34,000,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                24,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                9,100,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Comprehensive income | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                3,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                3,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                2,700,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                2,700,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | — | 
| Profit (loss) | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                3,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                3,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                2,700,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                2,700,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | — |