Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-03-31 |
As at 2021-04-01 |
As at 2021-03-31 |
As at 2020-04-01 |
|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||||
| Property, plant and equipment [abstract] | ||||
| Property, plant and equipment |
194,000,000
GBP
|
— |
180,800,000
GBP
|
— |
| Intangible assets and goodwill [abstract] | ||||
| Intangible assets other than goodwill [abstract] | ||||
| Intangible assets other than goodwill |
325,200,000
GBP
|
— |
290,000,000
GBP
|
— |
| Goodwill |
908,700,000
GBP
|
— |
808,500,000
GBP
|
— |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements [abstract] | ||||
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements |
8,200,000
GBP
|
— |
9,300,000
GBP
|
— |
| Miscellaneous non-current assets [abstract] | ||||
| Non-current net defined benefit asset |
31,100,000
GBP
|
— |
–
GBP
|
— |
| Trade and other current receivables [abstract] | ||||
| Trade and other current receivables |
325,100,000
GBP
|
— |
268,000,000
GBP
|
— |
| Classes of current inventories [abstract] | ||||
| Current inventories |
228,800,000
GBP
|
— |
167,800,000
GBP
|
— |
| Classes of current inventories, alternative [abstract] | ||||
| Cash and cash equivalents [abstract] | ||||
| Cash [abstract] | ||||
| Cash |
157,400,000
GBP
|
— |
134,100,000
GBP
|
— |
| Cash and cash equivalents |
156,700,000
GBP
|
131,100,000
GBP
|
131,100,000
GBP
|
105,400,000
GBP
|
| Miscellaneous assets [abstract] | ||||
| Derivative financial assets |
700,000
GBP
|
— |
1,700,000
GBP
|
— |
| Classes of other provisions [abstract] | ||||
| Other provisions [abstract] | ||||
| Other non-current provisions |
7,700,000
GBP
|
— |
8,400,000
GBP
|
— |
| Other current provisions |
20,700,000
GBP
|
— |
35,400,000
GBP
|
— |
| Borrowings [abstract] | ||||
| Non-current portion of non-current borrowings |
287,600,000
GBP
|
— |
322,300,000
GBP
|
— |
| Current borrowings and current portion of non-current borrowings [abstract] | ||||
| Current borrowings |
72,500,000
GBP
|
— |
3,000,000
GBP
|
— |
| Non-current portion of non-current borrowings, by type [abstract] | ||||
| Trade and other non-current payables [abstract] | ||||
| Trade and other non-current payables |
19,000,000
GBP
|
— |
16,800,000
GBP
|
— |
| Trade and other current payables [abstract] | ||||
| Trade and other current payables |
242,700,000
GBP
|
— |
186,700,000
GBP
|
— |
| Miscellaneous non-current liabilities [abstract] | ||||
| Non-current net defined benefit liability |
600,000
GBP
|
— |
22,500,000
GBP
|
— |
| Miscellaneous liabilities [abstract] | ||||
| Derivative financial liabilities |
900,000
GBP
|
— |
700,000
GBP
|
— |
| Issued capital [abstract] | ||||
| Issued capital |
38,000,000
GBP
|
— |
38,000,000
GBP
|
— |
| Retained earnings [abstract] | ||||
| Retained earnings |
1,274,800,000
GBP
|
— |
1,065,800,000
GBP
|
— |
| Accumulated other comprehensive income [abstract] | ||||
| Reserve of exchange differences on translation |
117,100,000
GBP
|
— |
73,200,000
GBP
|
— |
| Reserve of cash flow hedges |
400,000
GBP
|
— |
700,000
GBP
|
— |
| Miscellaneous equity [abstract] | ||||
| Capital redemption reserve |
200,000
GBP
|
— |
200,000
GBP
|
— |
| Net assets (liabilities) [abstract] | ||||
| Assets |
2,197,000,000
GBP
|
— |
1,877,900,000
GBP
|
— |
| Liabilities |
793,900,000
GBP
|
— |
710,300,000
GBP
|
— |
| Assets (liabilities) |
1,403,100,000
GBP
|
— |
1,167,600,000
GBP
|
— |
| Net current assets (liabilities) [abstract] | ||||
| Current assets |
712,700,000
GBP
|
— |
574,100,000
GBP
|
— |
| Current liabilities |
363,900,000
GBP
|
— |
248,000,000
GBP
|
— |
| Current assets (liabilities) |
348,800,000
GBP
|
— |
326,100,000
GBP
|
— |
| Assets less current liabilities [abstract] |