Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2019-12-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
22,500,000
GBP
|
2 4.3
GBP
|
— |
| Intangible assets and goodwill [abstract] | |||
| Intangible assets and goodwill |
183,200,000
GBP
|
182,900,000
GBP
|
— |
| Investment property [abstract] | |||
| Investment property |
1,200,000
GBP
|
1,200,000
GBP
|
— |
| Trade and other non-current receivables [abstract] | |||
| Trade and other non-current receivables |
1,000,000
GBP
|
3 .1
GBP
|
— |
| Miscellaneous non-current assets [abstract] | |||
| Non-current net defined benefit asset |
25,800,000
GBP
|
18. 1
GBP
|
— |
| Non-current investments other than investments accounted for using equity method |
1,000,000
GBP
|
2,900,000
GBP
|
— |
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
117 .4
GBP
|
76,600,000
GBP
|
— |
| Classes of current inventories [abstract] | |||
| Current inventories |
1,500,000
GBP
|
1,300,000
GBP
|
— |
| Classes of current inventories, alternative [abstract] | |||
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
261,600,000
GBP
|
17 3.4
GBP
|
175,700,000
GBP
|
| Miscellaneous current assets [abstract] | |||
| Current investments |
10,300,000
GBP
|
31. 1
GBP
|
— |
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
–
GBP
|
0 . 1
GBP
|
— |
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other non-current payables [abstract] | |||
| Trade and other non-current payables |
2,700,000
GBP
|
2,700,000
GBP
|
— |
| Trade and other current payables [abstract] | |||
| Trade and other current payables |
235,400,000
GBP
|
160,600,000
GBP
|
— |
| Miscellaneous non-current liabilities [abstract] | |||
| Non-current net defined benefit liability |
3,800,000
GBP
|
6. 1
GBP
|
— |
| Issued capital [abstract] | |||
| Issued capital |
7. 6
GBP
|
7. 6
GBP
|
— |
| Retained earnings [abstract] | |||
| Retained earnings |
245,300,000
GBP
|
211,900,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||
| Assets (liabilities) |
361,600,000
GBP
|
328,400,000
GBP
|
— |
| Net current assets (liabilities) [abstract] | |||
| Current assets |
391,800,000
GBP
|
282,600,000
GBP
|
— |
| Current liabilities |
257 .3
GBP
|
177 .4
GBP
|
— |
| Current assets (liabilities) |
134,500,000
GBP
|
105,200,000
GBP
|
— |
| Assets less current liabilities [abstract] |