Disclosure Of First-Time Adoption [Text Block]
| Concept | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 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 | — | — | 
                                                1,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                52,200,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                133,700,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                18,900,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                16,500,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | 
                                                400,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                85,900,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                237 .5
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                93,400,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                1,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | 
                                                133,700,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                18. 9
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                13. 0
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                2 .9
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                223. 7
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                24,300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                1,600,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                185,300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                9 .4
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                800,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                3. 9
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
| Comprehensive income | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                3,500,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                147 .3
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                153,300,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                2 .5
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                91,200,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                78,000,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                12 .2
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | 
                                                1,000,000
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
| Profit (loss) | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                147 .0
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                147 .0
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                78. 1
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | 
                                                78. 1
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | 
                                                –
                                                
                                                    
                                                        GBP
                                                    
                                                
                                             | — | — | — | — | — | — | — |