Statement Of Financial Position [Abstract]
| Concept |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||
| Assets [abstract] | |||||||||||||||
| Non-current assets [abstract] | |||||||||||||||
| Property, plant and equipment | — |
300,000
GBP
|
— | — | — | — | — | — | — |
500,000
GBP
|
— | — | — | — | — |
| Investment property | — |
2,738,000,000
GBP
|
— | — | — | — | — | — | — |
2,751,900,000
GBP
|
— | — | — | — | — |
| Investments accounted for using equity method | — |
18,300,000
GBP
|
— | — | — | — | — | — | — |
3,800,000
GBP
|
— | — | — | — | — |
| Deferred tax assets | — |
600,000
GBP
|
— | — | — | — | — | — | — |
600,000
GBP
|
— | — | — | — | — |
| Non-current assets | — |
2,771,100,000
GBP
|
— | — | — | — | — | — | — |
2,772,000,000
GBP
|
— | — | — | — | — |
| Current assets [abstract] | |||||||||||||||
| Trade and other current receivables | — |
33,100,000
GBP
|
— | — | — | — | — | — | — |
28,600,000
GBP
|
— | — | — | — | — |
| Cash and cash equivalents | — |
118,000,000
GBP
|
— | — | — | — | — | — | — |
243,500,000
GBP
|
— | — | — |
46,600,000
GBP
|
— |
| Current assets | — |
151,500,000
GBP
|
— | — | — | — | — | — | — |
348,500,000
GBP
|
— | — | — | — | — |
| Assets | — |
2,922,600,000
GBP
|
— | — | — | — | — | — | — |
3,120,500,000
GBP
|
— | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||
| Equity [abstract] | |||||||||||||||
| Issued capital | — |
296,100,000
GBP
|
— | — | — | — | — | — | — |
294,800,000
GBP
|
— | — | — | — | — |
| Retained earnings | — |
135,300,000
GBP
|
— | — | — | — | — | — | — |
345,100,000
GBP
|
— | — | — | — | — |
| Share premium | — |
924,500,000
GBP
|
— | — | — | — | — | — | — |
918,500,000
GBP
|
— | — | — | — | — |
| Equity |
231,600,000
GBP
|
1,587,500,000
GBP
|
924,500,000
GBP
|
296,100,000
GBP
|
135,300,000
GBP
|
294,800,000
GBP
|
231,200,000
GBP
|
918,500,000
GBP
|
345,100,000
GBP
|
1,789,600,000
GBP
|
231,200,000
GBP
|
269,200,000
GBP
|
267,200,000
GBP
|
1,530,700,000
GBP
|
763,100,000
GBP
|
| Liabilities [abstract] | |||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||
| Non-current liabilities | — |
1,257,300,000
GBP
|
— | — | — | — | — | — | — |
1,255,800,000
GBP
|
— | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||
| Trade and other current payables | — |
46,800,000
GBP
|
— | — | — | — | — | — | — |
44,900,000
GBP
|
— | — | — | — | — |
| Current liabilities | — |
77,800,000
GBP
|
— | — | — | — | — | — | — |
75,100,000
GBP
|
— | — | — | — | — |
| Liabilities | — |
1,335,100,000
GBP
|
— | — | — | — | — | — | — |
1,330,900,000
GBP
|
— | — | — | — | — |