Statement Of Cash Flows [Abstract]
| Concept | 2023-12-31 to 2024-12-28 | 2023-01-01 to 2023-12-30 | 
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) investing activities [abstract] | ||
| Purchase of interests in investments accounted for using equity method | 
                                                100,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             |