Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-12-31 |
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 |
369,900,000
GBP
|
355,500,000
GBP
|
— | — |
| Intangible assets and goodwill [abstract] | ||||
| Intangible assets and goodwill |
1,394,600,000
GBP
|
1,384,100,000
GBP
|
— | — |
| Trade and other non-current receivables [abstract] | ||||
| Trade and other non-current receivables |
6,300,000
GBP
|
2,100,000
GBP
|
— | — |
| Trade and other current receivables [abstract] | ||||
| Trade and other current receivables |
245,700,000
GBP
|
243,400,000
GBP
|
— | — |
| Classes of current inventories [abstract] | ||||
| Current inventories |
286,200,000
GBP
|
196,800,000
GBP
|
— | — |
| Classes of current inventories, alternative [abstract] | ||||
| Cash and cash equivalents [abstract] | ||||
| Cash and cash equivalents |
583,300,000
GBP
|
418,900,000
GBP
|
418,900,000
GBP
|
489,400,000
GBP
|
| Borrowings [abstract] | ||||
| Non-current portion of non-current borrowings |
1,104,000,000
GBP
|
1,074,900,000
GBP
|
— | — |
| Current borrowings and current portion of non-current borrowings [abstract] | ||||
| Current borrowings |
107,100,000
GBP
|
114,300,000
GBP
|
— | — |
| Non-current portion of non-current borrowings, by type [abstract] | ||||
| Trade and other non-current payables [abstract] | ||||
| Trade and other non-current payables |
9,100,000
GBP
|
9,800,000
GBP
|
— | — |
| Trade and other current payables [abstract] | ||||
| Trade and other current payables |
876,300,000
GBP
|
721,000,000
GBP
|
— | — |
| Miscellaneous non-current liabilities [abstract] | ||||
| Non-current net defined benefit liability |
61,200,000
GBP
|
78,700,000
GBP
|
— | — |
| Issued capital [abstract] | ||||
| Issued capital |
69,900,000
GBP
|
11,600,000
GBP
|
— | — |
| Retained earnings [abstract] | ||||
| Retained earnings |
1,184,900,000
GBP
|
662,400,000
GBP
|
— | — |
| Accumulated other comprehensive income [abstract] | ||||
| Reserve of exchange differences on translation |
6,500,000
GBP
|
2,700,000
GBP
|
— | — |
| Reserve of cash flow hedges |
4,300,000
GBP
|
6,700,000
GBP
|
— | — |
| Miscellaneous equity [abstract] | ||||
| Capital redemption reserve |
9,300,000
GBP
|
9,300,000
GBP
|
— | — |
| Merger reserve |
143,900,000
GBP
|
143,900,000
GBP
|
— | — |
| Capital reserve |
6,600,000
GBP
|
6,600,000
GBP
|
— | — |
| Net assets (liabilities) [abstract] | ||||
| Assets |
3,104,300,000
GBP
|
2,842,500,000
GBP
|
— | — |
| Liabilities |
2,331,800,000
GBP
|
2,182,100,000
GBP
|
— | — |
| Assets (liabilities) |
772,500,000
GBP
|
660,400,000
GBP
|
— | — |
| Net current assets (liabilities) [abstract] | ||||
| Current assets |
1,125,400,000
GBP
|
867,900,000
GBP
|
— | — |
| Current liabilities |
1,041,900,000
GBP
|
905,200,000
GBP
|
— | — |
| Assets less current liabilities [abstract] |