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 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||
| Assets [abstract] | |||||||||||||||
| Non-current assets [abstract] | |||||||||||||||
| Property, plant and equipment | — | — | — | — |
500,000
GBP
|
— | — |
300,000
GBP
|
— | — | — | — | — | — | — |
| Investment property | — | — | — | — |
2,751,900,000
GBP
|
— | — |
2,453,300,000
GBP
|
— | — | — | — | — | — | — |
| Investments accounted for using equity method | — | — | — | — |
3,800,000
GBP
|
— | — |
700,000
GBP
|
— | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — |
600,000
GBP
|
— | — |
500,000
GBP
|
— | — | — | — | — | — | — |
| Non-current assets | — | — | — | — |
2,772,000,000
GBP
|
— | — |
2,468,400,000
GBP
|
— | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||
| Trade and other current receivables | — | — | — | — |
28,600,000
GBP
|
— | — |
27,400,000
GBP
|
— | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — |
243,500,000
GBP
|
— | — |
46,600,000
GBP
|
— | — |
18,500,000
GBP
|
— | — | — | — |
| Current assets | — | — | — | — |
348,500,000
GBP
|
— | — |
88,700,000
GBP
|
— | — | — | — | — | — | — |
| Assets | — | — | — | — |
3,120,500,000
GBP
|
— | — |
2,557,100,000
GBP
|
— | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||
| Equity [abstract] | |||||||||||||||
| Issued capital | — | — | — | — |
294,800,000
GBP
|
— | — |
267,200,000
GBP
|
— | — | — | — | — | — | — |
| Retained earnings | — | — | — | — |
345,100,000
GBP
|
— | — |
269,200,000
GBP
|
— | — | — | — | — | — | — |
| Share premium | — | — | — | — |
918,500,000
GBP
|
— | — |
763,100,000
GBP
|
— | — | — | — | — | — | — |
| Equity |
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
|
1,530,700,000
GBP
|
267,200,000
GBP
|
763,100,000
GBP
|
1,302,400,000
GBP
|
231,200,000
GBP
|
595,500,000
GBP
|
241,300,000
GBP
|
234,400,000
GBP
|
| Liabilities [abstract] | |||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||
| Non-current liabilities | — | — | — | — |
1,255,800,000
GBP
|
— | — |
960,200,000
GBP
|
— | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||
| Trade and other current payables | — | — | — | — |
44,900,000
GBP
|
— | — |
40,700,000
GBP
|
— | — | — | — | — | — | — |
| Current liabilities | — | — | — | — |
75,100,000
GBP
|
— | — |
66,200,000
GBP
|
— | — | — | — | — | — | — |
| Liabilities | — | — | — | — |
1,330,900,000
GBP
|
— | — |
1,026,400,000
GBP
|
— | — | — | — | — | — | — |