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 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 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — | — |
177,300,000
GBP
|
— | — |
170,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Right-of-use assets | — | — | — | — | — | — |
45,800,000
GBP
|
— | — |
58,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Current tax assets | — | — | — | — | — | — |
11,900,000
GBP
|
— | — |
21,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — | — |
4,900,000
GBP
|
— | — |
9,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — | — | — |
158,400,000
GBP
|
— | — |
86,400,000
GBP
|
— | — | — | — |
3 4.8
GBP
|
— | — | — | — | — | — |
| Assets | — | — | — | — | — | — |
2,101,200,000
GBP
|
— | — |
1,8 45.8
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Issued capital | — | — | — | — | — | — |
47. 1
GBP
|
— | — |
47,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — | — | — | — |
772,800,000
GBP
|
— | — |
587,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Share premium | — | — | — | — | — | — |
231,400,000
GBP
|
— | — |
228,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Treasury shares | — | — | — | — | — | — |
3,000,000
GBP
|
— | — |
1,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — | — | — | — | — | — |
1,108. 5
GBP
|
— | — |
899,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Equity |
3,000,000
GBP
|
700,000
GBP
|
47,100,000
GBP
|
60,900,000
GBP
|
231,400,000
GBP
|
772,800,000
GBP
|
1,1 08.5
GBP
|
1. 5
GBP
|
587 8
GBP
|
899,400,000
GBP
|
47,000,000
GBP
|
228 5
GBP
|
1,400,000
GBP
|
39. 0
GBP
|
719,900,000
GBP
|
81,500,000
GBP
|
700,000
GBP
|
51,400,000
GBP
|
–
GBP
|
44,600,000
GBP
|
543,100,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||
| Current tax liabilities | — | — | — | — | — | — |
19,900,000
GBP
|
— | — |
20,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — | — |
60,400,000
GBP
|
— | — |
57,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — | — | — | — |
992. 7
GBP
|
— | — |
9 46.4
GBP
|
— | — | — | — | — | — | — | — | — | — | — |