Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
37,500,000
GBP
|
40,900,000
GBP
|
— |
| Intangible assets and goodwill [abstract] | |||
| Intangible assets other than goodwill [abstract] | |||
| Intangible assets other than goodwill |
17,500,000
GBP
|
35,200,000
GBP
|
— |
| Goodwill |
494,400,000
GBP
|
570,600,000
GBP
|
— |
| Investments accounted for using equity method [abstract] | |||
| Investments in associates accounted for using equity method |
1,800,000
GBP
|
-
GBP
|
— |
| Trade and other non-current receivables [abstract] | |||
| Trade and other non-current receivables |
400,000
GBP
|
400,000
GBP
|
— |
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
137,600,000
GBP
|
124,100,000
GBP
|
— |
| Categories of current financial assets [abstract] | |||
| Current financial assets at fair value through profit or loss [abstract] | |||
| Current financial assets at fair value through profit or loss |
232,800,000
GBP
|
167,800,000
GBP
|
— |
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
268,200,000
GBP
|
280,300,000
GBP
|
197,300,000
GBP
|
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
49,700,000
GBP
|
49,500,000
GBP
|
— |
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other non-current payables [abstract] | |||
| Trade and other non-current payables |
59,700,000
GBP
|
87,500,000
GBP
|
— |
| Trade and other current payables [abstract] | |||
| Trade and other current payables |
221,400,000
GBP
|
202,400,000
GBP
|
— |
| Categories of current financial liabilities [abstract] | |||
| Current financial liabilities at fair value through profit or loss [abstract] | |||
| Current financial liabilities at fair value through profit or loss |
80,300,000
GBP
|
49,200,000
GBP
|
— |
| Issued capital [abstract] | |||
| Issued capital |
10,900,000
GBP
|
10,900,000
GBP
|
— |
| Retained earnings [abstract] | |||
| Retained earnings |
527,000,000
GBP
|
578,900,000
GBP
|
— |
| Accumulated other comprehensive income [abstract] | |||
| Reserve of exchange differences on translation |
2,000,000
GBP
|
3,700,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||
| Assets |
1,207,600,000
GBP
|
1,242,000,000
GBP
|
— |
| Liabilities |
418,100,000
GBP
|
398,100,000
GBP
|
— |
| Net current assets (liabilities) [abstract] | |||
| Current assets |
639,900,000
GBP
|
575,500,000
GBP
|
— |
| Current liabilities |
306,400,000
GBP
|
254,400,000
GBP
|
— |
| Assets less current liabilities [abstract] |