Statement Of Financial Position [Abstract]
| Concept |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-01-01 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||
| Non-current assets [abstract] | |||||||||||||||||||||
| Property, plant and equipment | — | — |
66,600,000
GBP
|
— | — | — | — | — | — |
65,800,000
GBP
|
79,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Investment property | — | — |
800,000
GBP
|
— | — | — | — | — | — |
2,700,000
GBP
|
5,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Non-current assets | — | — |
383,400,000
GBP
|
— | — | — | — | — | — |
387,500,000
GBP
|
402,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||
| Current inventories | — | — |
288,500,000
GBP
|
— | — | — | — | — | — |
294,200,000
GBP
|
338,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — |
328,300,000
GBP
|
— | — | — | — | — | — |
234,600,000
GBP
|
275,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current tax assets, current | — | — |
4,700,000
GBP
|
— | — | — | — | — | — |
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — |
468,600,000
GBP
|
— | — | — | — | — | — |
400,500,000
GBP
|
251,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current assets | — | — |
1,324,200,000
GBP
|
— | — | — | — | — | — |
1,101,100,000
GBP
|
1,051,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Assets | — | — |
1,707,600,000
GBP
|
— | — | — | — | — | — |
1,488,600,000
GBP
|
1,454,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Issued capital | — | — |
2,300,000
GBP
|
— | — | — | — | — | — |
2,300,000
GBP
|
2,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Retained earnings | — | — |
427,100,000
GBP
|
— | — | — | — | — | — |
373,100,000
GBP
|
346,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Share premium | — | — |
45,800,000
GBP
|
— | — | — | — | — | — |
45,500,000
GBP
|
38,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — | — |
474,200,000
GBP
|
— | — | — | — | — | — |
420,100,000
GBP
|
386,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Equity |
427,100,000
GBP
|
1,000,000
GBP
|
474,200,000
GBP
|
45,800,000
GBP
|
2,300,000
GBP
|
373,100,000
GBP
|
2,300,000
GBP
|
800,000
GBP
|
45,500,000
GBP
|
420,100,000
GBP
|
386,900,000
GBP
|
800,000
GBP
|
38,500,000
GBP
|
396,800,000
GBP
|
356,800,000
GBP
|
2,300,000
GBP
|
2,300,000
GBP
|
38,500,000
GBP
|
800,000
GBP
|
346,900,000
GBP
|
386,900,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||
| Non-current provisions | — | — |
23,900,000
GBP
|
— | — | — | — | — | — |
26,000,000
GBP
|
21,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Trade and other non-current payables | — | — |
32,600,000
GBP
|
— | — | — | — | — | — |
1,700,000
GBP
|
3,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — |
10,000,000
GBP
|
— | — | — | — | — | — |
12,500,000
GBP
|
8,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — |
106,500,000
GBP
|
— | — | — | — | — | — |
79,700,000
GBP
|
80,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||
| Current provisions [abstract] | |||||||||||||||||||||
| Current provisions | — | — |
33,400,000
GBP
|
— | — | — | — | — | — |
4,900,000
GBP
|
7,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Trade and other current payables | — | — |
891,400,000
GBP
|
— | — | — | — | — | — |
847,900,000
GBP
|
842,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current tax liabilities, current | — | — |
–
GBP
|
— | — | — | — | — | — |
1,000,000
GBP
|
9,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current liabilities | — | — |
1,126,900,000
GBP
|
— | — | — | — | — | — |
988,800,000
GBP
|
986,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Liabilities | — | — |
1,233,400,000
GBP
|
— | — | — | — | — | — |
1,068,500,000
GBP
|
1,067,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — |