Statement Of Financial Position [Abstract]
| Concept |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||
| Assets [abstract] | |||||||||||||||
| Non-current assets [abstract] | |||||||||||||||
| Property, plant and equipment | — | — | — |
41,800,000
GBP
|
— |
39,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Investment property | — | — | — |
1,850,500,000
GBP
|
— |
2,295,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Investments accounted for using equity method | — | — | — |
1,400,000
GBP
|
— |
2,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — |
–
GBP
|
— |
2,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — |
1,900,200,000
GBP
|
— |
2,351,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||
| Trade and other current receivables | — | — | — |
16,700,000
GBP
|
— |
15,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — |
70,600,000
GBP
|
— |
113,900,000
GBP
|
— | — | — | — |
167,400,000
GBP
|
— | — | — | — |
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners | — | — | — |
172,700,000
GBP
|
— |
20,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets | — | — | — |
88,000,000
GBP
|
— |
129,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Assets | — | — | — |
2,160,900,000
GBP
|
— |
2,501,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||
| Equity [abstract] | |||||||||||||||
| Issued capital | — | — | — |
11,000,000
GBP
|
— |
11,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — |
728,400,000
GBP
|
— |
1,011,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Share premium | — | — | — |
83,100,000
GBP
|
— |
83,100,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other reserves | — | — | — |
106,700,000
GBP
|
— |
115,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity |
83,100,000
GBP
|
11,000,000
GBP
|
728,400,000
GBP
|
929,200,000
GBP
|
106,700,000
GBP
|
1,220,800,000
GBP
|
83,100,000
GBP
|
1,011,300,000
GBP
|
11,000,000
GBP
|
115,400,000
GBP
|
1,330,700,000
GBP
|
1,147,900,000
GBP
|
88,700,000
GBP
|
83,100,000
GBP
|
11,000,000
GBP
|
| Liabilities [abstract] | |||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||
| Deferred tax liabilities | — | — | — |
88,700,000
GBP
|
— |
110,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — |
968,900,000
GBP
|
— |
1,046,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||
| Trade and other current payables | — | — | — |
68,600,000
GBP
|
— |
58,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current tax liabilities, current | — | — | — |
300,000
GBP
|
— |
2,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — |
262,800,000
GBP
|
— |
234,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — |
1,231,700,000
GBP
|
— |
1,280,600,000
GBP
|
— | — | — | — | — | — | — | — | — |