Statement Of Financial Position [Abstract]
| Concept |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-04-01 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
As at 2020-04-01 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Assets [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Non-current assets [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — | — | — |
194,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
180,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Goodwill | — | — | — | — | — | — | — |
908,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
808,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Intangible assets other than goodwill | — | — | — | — | — | — | — |
325,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
290,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements | — | — | — | — | — | — | — |
8,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
9,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — | — | — |
2,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current tax assets, non-current | — | — | — | — | — | — | — |
14,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
13,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — | — | — | — | — |
1,484,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,303,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Current inventories | — | — | — | — | — | — | — |
228,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
167,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — | — | — | — | — | — |
325,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
268,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current tax assets, current | — | — | — | — | — | — | — |
700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
2,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — | — | — | — |
156,700,000
GBP
|
— | — | — | — |
131,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
131,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
105,400,000
GBP
|
— |
| Current assets | — | — | — | — | — | — | — |
712,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
574,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Assets | — | — | — | — | — | — | — |
2,197,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,877,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Equity [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Issued capital | — | — | — | — | — | — | — |
38,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
38,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — | — | — | — | — |
1,274,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,065,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Share premium | — | — | — | — | — | — | — |
23,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
23,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Treasury shares | — | — | — | — | — | — | — |
30,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
20,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Other reserves | — | — | — | — | — | — | — |
19,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
13,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — | — | — | — | — | — | — |
1,402,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,167,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-controlling interests | — | — | — | — | — | — | — |
400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
200,000
GBP
|
30,700,000
GBP
|
400,000
GBP
|
38,000,000
GBP
|
117,100,000
GBP
|
23,600,000
GBP
|
1,274,800,000
GBP
|
1,403,100,000
GBP
|
400,000
GBP
|
19,900,000
GBP
|
1,065,800,000
GBP
|
23,600,000
GBP
|
1,167,600,000
GBP
|
600,000
GBP
|
38,000,000
GBP
|
20,900,000
GBP
|
700,000
GBP
|
73,200,000
GBP
|
13,600,000
GBP
|
200,000
GBP
|
200,000
GBP
|
20,900,000
GBP
|
1,065,800,000
GBP
|
13,600,000
GBP
|
1,167,600,000
GBP
|
38,000,000
GBP
|
23,600,000
GBP
|
700,000
GBP
|
600,000
GBP
|
73,200,000
GBP
|
200,000
GBP
|
148,700,000
GBP
|
23,600,000
GBP
|
38,000,000
GBP
|
7,700,000
GBP
|
700,000
GBP
|
14,300,000
GBP
|
949,200,000
GBP
|
1,136,900,000
GBP
|
100,000
GBP
|
| Liabilities [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Non-current liabilities [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Non-current provisions [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Other non-current provisions | — | — | — | — | — | — | — |
7,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
8,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other non-current payables | — | — | — | — | — | — | — |
19,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
16,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — | — | — |
58,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
40,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — | — | — | — | — |
430,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
462,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Current provisions [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Other current provisions | — | — | — | — | — | — | — |
20,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
35,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current payables | — | — | — | — | — | — | — |
242,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
186,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current tax liabilities, current | — | — | — | — | — | — | — |
11,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
8,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — | — | — | — | — |
363,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
248,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — | — | — | — | — |
793,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
710,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |