Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2022-12-31 |
|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||
| Property, plant and equipment [abstract] | ||
| Property, plant and equipment |
136 . 2
GBP
|
16 0 .7
GBP
|
| Intangible assets and goodwill [abstract] | ||
| Intangible assets other than goodwill [abstract] | ||
| Intangible assets other than goodwill |
167 .1
GBP
|
18 4 .1
GBP
|
| Goodwill |
56 5. 5
GBP
|
6 06 .1
GBP
|
| Investments accounted for using equity method [abstract] | ||
| Investments in associates accounted for using equity method |
10,800,000
GBP
|
2,900,000
GBP
|
| Trade and other non-current receivables [abstract] | ||
| Other non-current receivables |
5,900,000
GBP
|
4,200,000
GBP
|
| Miscellaneous non-current assets [abstract] | ||
| Non-current net defined benefit asset |
2 .4
GBP
|
–
GBP
|
| Non-current derivative financial assets |
400,000
GBP
|
400,000
GBP
|
| Trade and other current receivables [abstract] | ||
| Trade and other current receivables |
3 1 7. 9
GBP
|
362. 5
GBP
|
| Classes of current inventories [abstract] | ||
| Current inventories |
231. 8
GBP
|
26 3. 3
GBP
|
| Classes of current inventories, alternative [abstract] | ||
| Cash and cash equivalents [abstract] | ||
| Cash and cash equivalents |
138 . 5
GBP
|
2 28 .1
GBP
|
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | ||
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners |
9 7. 5
GBP
|
1 .7
GBP
|
| Miscellaneous current assets [abstract] | ||
| Current derivative financial assets |
5,800,000
GBP
|
1. 3
GBP
|
| Miscellaneous assets [abstract] | ||
| Equity instruments held |
24. 3
GBP
|
29. 3
GBP
|
| Debt instruments held [abstract] | ||
| Debt instruments held |
2 1 .7
GBP
|
18 .9
GBP
|
| Borrowings [abstract] | ||
| Current borrowings and current portion of non-current borrowings [abstract] | ||
| Current borrowings |
–
GBP
|
0 .1
GBP
|
| Trade and other non-current payables [abstract] | ||
| Other non-current payables |
1 5 .1
GBP
|
13 .8
GBP
|
| Trade and other current payables [abstract] | ||
| Trade and other current payables |
36 9. 4
GBP
|
3 7 3 .7
GBP
|
| Miscellaneous non-current liabilities [abstract] | ||
| Non-current net defined benefit liability |
11 .6
GBP
|
8 .9
GBP
|
| Non-current derivative financial liabilities |
100,000
GBP
|
0. 2
GBP
|
| Miscellaneous current liabilities [abstract] | ||
| Current derivative financial liabilities |
100,000
GBP
|
2. 3
GBP
|
| Issued capital [abstract] | ||
| Issued capital |
5,300,000
GBP
|
5,500,000
GBP
|
| Retained earnings [abstract] | ||
| Retained earnings |
1,030,000,000
GBP
|
1,113,000,000
GBP
|
| Accumulated other comprehensive income [abstract] | ||
| Reserve of exchange differences on translation |
4 3.0
GBP
|
8 6.0
GBP
|
| Reserve of cash flow hedges |
1,900,000
GBP
|
3 .1
GBP
|
| Miscellaneous equity [abstract] | ||
| Capital redemption reserve |
1,200,000
GBP
|
1,000,000
GBP
|
| Merger reserve |
3 .1
GBP
|
3 .1
GBP
|
| Net assets (liabilities) [abstract] | ||
| Assets |
1 , 8 1 7. 7
GBP
|
1,948 .0
GBP
|
| Liabilities |
501 .8
GBP
|
5 11 .1
GBP
|
| Assets (liabilities) |
1, 315.9
GBP
|
1,436,900,000
GBP
|
| Net current assets (liabilities) [abstract] | ||
| Current assets |
7 98 .7
GBP
|
865. 5
GBP
|
| Current liabilities |
42 2 . 8
GBP
|
4 18 . 0
GBP
|
| Current assets (liabilities) |
375. 9
GBP
|
4 4 7. 5
GBP
|
| Assets less current liabilities [abstract] |