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 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 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | ||||||||||||||||||
| Assets [abstract] | ||||||||||||||||||
| Non-current assets [abstract] | ||||||||||||||||||
| Property, plant and equipment |
4,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,900,000
GBP
|
— | — | — | — | — | — | — |
| Investment property |
2,643,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,366,700,000
GBP
|
— | — | — | — | — | — | — |
| Deferred tax assets |
–
GBP
|
— | — | — | — | — | — | — | — | — |
300,000
GBP
|
— | — | — | — | — | — | — |
| Non-current assets |
2,651,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,37 3.5
GBP
|
— | — | — | — | — | — | — |
| Current assets [abstract] | ||||||||||||||||||
| Trade and other current receivables |
45,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
23,500,000
GBP
|
— | — | — | — | — | — | — |
| Cash and cash equivalents |
18,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
49,000,000
GBP
|
— | — | — | — |
191,000,000
GBP
|
— | — |
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners |
123,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
65,900,000
GBP
|
— | — | — | — | — | — | — |
| Current assets |
187 .3
GBP
|
— | — | — | — | — | — | — | — | — |
138,400,000
GBP
|
— | — | — | — | — | — | — |
| Assets |
2,839. 1
GBP
|
— | — | — | — | — | — | — | — | — |
2,511,900,000
GBP
|
— | — | — | — | — | — | — |
| Equity and liabilities [abstract] | ||||||||||||||||||
| Equity [abstract] | ||||||||||||||||||
| Issued capital |
191,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
181. 1
GBP
|
— | — | — | — | — | — | — |
| Retained earnings |
1,219,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,300,300,000
GBP
|
— | — | — | — | — | — | — |
| Share premium |
295,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
295,500,000
GBP
|
— | — | — | — | — | — | — |
| Treasury shares |
9,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
9,900,000
GBP
|
— | — | — | — | — | — | — |
| Other reserves |
91,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
32,600,000
GBP
|
— | — | — | — | — | — | — |
| Equity |
1,787,700,000
GBP
|
295,500,000
GBP
|
191,600,000
GBP
|
9,900,000
GBP
|
1,219,500,000
GBP
|
91. 0
GBP
|
9,900,000
GBP
|
181. 1
GBP
|
295,500,000
GBP
|
1,300 .3
GBP
|
1, 799.6
GBP
|
32,600,000
GBP
|
9,600,000
GBP
|
1,219,400,000
GBP
|
33. 1
GBP
|
1,719,500,000
GBP
|
181. 1
GBP
|
295,500,000
GBP
|
| Liabilities [abstract] | ||||||||||||||||||
| Non-current liabilities [abstract] | ||||||||||||||||||
| Non-current liabilities |
893,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
626,500,000
GBP
|
— | — | — | — | — | — | — |
| Current liabilities [abstract] | ||||||||||||||||||
| Trade and other current payables |
107 .8
GBP
|
— | — | — | — | — | — | — | — | — |
85,800,000
GBP
|
— | — | — | — | — | — | — |
| Current liabilities |
157 .6
GBP
|
— | — | — | — | — | — | — | — | — |
85,800,000
GBP
|
— | — | — | — | — | — | — |
| Liabilities |
1,051,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
712,300,000
GBP
|
— | — | — | — | — | — | — |