Statement Of Cash Flows [Abstract]
| Concept |
As at 2023-03-31 |
2022-04-01 to 2023-03-31 |
2021-04-01 to 2022-03-31 |
As at 2022-03-31 |
As at 2021-03-31 |
|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||
| Cash flows from (used in) operating activities [abstract] | |||||
| Interest paid, classified as operating activities | — |
29,000,000
GBP
|
25,000,000
GBP
|
— | — |
| Interest received, classified as operating activities | — |
1,600,000
GBP
|
400,000
GBP
|
— | — |
| Other inflows (outflows) of cash, classified as operating activities | — |
18,000,000
GBP
|
21,500,000
GBP
|
— | — |
| Cash flows from (used in) operating activities | — |
94,100,000
GBP
|
94,600,000
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | |||||
| Proceeds from sales of property, plant and equipment, classified as investing activities | — |
77,800,000
GBP
|
15,100,000
GBP
|
— | — |
| Cash flows from (used in) investing activities | — |
130,400,000
GBP
|
293,900,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | |||||
| Repayments of borrowings, classified as financing activities | — |
–
GBP
|
20,000,000
GBP
|
— | — |
| Dividends paid, classified as financing activities | — |
88,900,000
GBP
|
75,400,000
GBP
|
— | — |
| Cash flows from (used in) financing activities | — |
89,200,000
GBP
|
396,200,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — |
125,500,000
GBP
|
196,900,000
GBP
|
— | — |
| Cash and cash equivalents |
118,000,000
GBP
|
— | — |
243,500,000
GBP
|
46,600,000
GBP
|