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 |
150. 5
GBP
|
156 .0
GBP
|
3 18 .1
GBP
|
| Intangible assets and goodwill [abstract] | |||
| Intangible assets other than goodwill [abstract] | |||
| Intangible assets other than goodwill |
169,100,000
GBP
|
1 0 7. 8
GBP
|
152. 8
GBP
|
| Goodwill |
631. 5
GBP
|
5 7 7. 0
GBP
|
646,800,000
GBP
|
| Intangible assets and goodwill |
800,600,000
GBP
|
684,800,000
GBP
|
799,600,000
GBP
|
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
315. 9
GBP
|
293 . 3
GBP
|
3 3 7. 2
GBP
|
| Classes of current inventories [abstract] | |||
| Current inventories |
1 8 7. 9
GBP
|
16 8. 5
GBP
|
1 9 7. 2
GBP
|
| Classes of current inventories, alternative [abstract] | |||
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
167 .8
GBP
|
222,200,000
GBP
|
213 .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 |
10,400,000
GBP
|
17 8 .7
GBP
|
18,900,000
GBP
|
| Miscellaneous current assets [abstract] | |||
| Current derivative financial assets |
0. 3
GBP
|
1 .9
GBP
|
1. 5
GBP
|
| Miscellaneous assets [abstract] | |||
| Equity instruments held |
24 . 3
GBP
|
39,400,000
GBP
|
–
GBP
|
| Debt instruments held [abstract] | |||
| Debt instruments held |
2 3.0
GBP
|
–
GBP
|
–
GBP
|
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
–
GBP
|
1 04 . 5
GBP
|
98 .9
GBP
|
| Current borrowings and current portion of non-current borrowings [abstract] | |||
| Current borrowings |
–
GBP
|
1 3 .1
GBP
|
8 0 .7
GBP
|
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other non-current payables [abstract] | |||
| Other non-current payables |
1 3 . 8
GBP
|
24 .7
GBP
|
21 . 3
GBP
|
| Trade and other current payables [abstract] | |||
| Trade and other current payables |
33 0. 2
GBP
|
28 8. 3
GBP
|
29 6 .8
GBP
|
| Miscellaneous non-current liabilities [abstract] | |||
| Non-current net defined benefit liability |
22 . 3
GBP
|
20,400,000
GBP
|
2 7. 5
GBP
|
| Miscellaneous current liabilities [abstract] | |||
| Current derivative financial liabilities |
1 . 2
GBP
|
100,000
GBP
|
100,000
GBP
|
| Issued capital [abstract] | |||
| Issued capital |
5 .8
GBP
|
6 .0
GBP
|
6 .0
GBP
|
| Retained earnings [abstract] | |||
| Retained earnings |
9 5 7. 6
GBP
|
8 82.6
GBP
|
96 4.4
GBP
|
| Accumulated other comprehensive income [abstract] | |||
| Reserve of exchange differences on translation |
66. 2
GBP
|
9 8.0
GBP
|
98,600,000
GBP
|
| Reserve of cash flow hedges |
3. 5
GBP
|
1. 9
GBP
|
1. 4
GBP
|
| Miscellaneous equity [abstract] | |||
| Capital redemption reserve |
0 .7
GBP
|
500,000
GBP
|
0. 5
GBP
|
| Merger reserve |
3,100,000
GBP
|
3,100,000
GBP
|
3,100,000
GBP
|
| Net assets (liabilities) [abstract] | |||
| Assets |
1,7 6 8 .1
GBP
|
1,7 9 6 . 2
GBP
|
1,949 .6
GBP
|
| Liabilities |
50 6 . 8
GBP
|
576 . 5
GBP
|
647,000,000
GBP
|
| Assets (liabilities) |
1,261. 3
GBP
|
1 , 2 1 9.7
GBP
|
1 , 302 .6
GBP
|
| Net current assets (liabilities) [abstract] | |||
| Current assets |
688 .0
GBP
|
8 6 8 .7
GBP
|
77 2.0
GBP
|
| Current liabilities |
393. 7
GBP
|
392. 0
GBP
|
4 39 .7
GBP
|
| Current assets (liabilities) |
294. 3
GBP
|
476 .7
GBP
|
3 32. 3
GBP
|
| Assets less current liabilities [abstract] |