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] | |||||||||||||||
| Investment property | — | — | — |
4,843,600,000
GBP
|
— |
4,847,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Trade and other non-current receivables | — | — | — |
1,000,000
GBP
|
— |
2,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other non-current financial assets | — | — | — |
2,300,000
GBP
|
— |
—
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — |
5,043,600,000
GBP
|
— |
5,057,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||
| Trade and other current receivables | — | — | — |
22,000,000
GBP
|
— |
24,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — |
36,200,000
GBP
|
— |
47,400,000
GBP
|
— | — | — | — |
70,900,000
GBP
|
— | — | — | — |
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners | — | — | — |
—
GBP
|
— |
25,100,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets | — | — | — |
58,400,000
GBP
|
— |
97,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Assets | — | — | — |
5,102,000,000
GBP
|
— |
5,155,100,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||
| Equity [abstract] | |||||||||||||||
| Issued capital | — | — | — |
19,000,000
GBP
|
— |
18,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — |
1,801,900,000
GBP
|
— |
1,731,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Share premium | — | — | — |
49,200,000
GBP
|
— |
764,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity |
49,200,000
GBP
|
19,000,000
GBP
|
1,801,900,000
GBP
|
3,334,000,000
GBP
|
1,463,900,000
GBP
|
3,350,000,000
GBP
|
764,300,000
GBP
|
835,100,000
GBP
|
1,731,900,000
GBP
|
18,700,000
GBP
|
4,076,500,000
GBP
|
2,331,300,000
GBP
|
964,500,000
GBP
|
762,000,000
GBP
|
18,700,000
GBP
|
| Liabilities [abstract] | |||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||
| Trade and other non-current payables | — | — | — |
1,000,000
GBP
|
— |
2,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — |
1,620,300,000
GBP
|
— |
1,658,100,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||
| Trade and other current payables | — | — | — |
106,900,000
GBP
|
— |
111,200,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — |
147,700,000
GBP
|
— |
147,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — |
1,768,000,000
GBP
|
— |
1,805,100,000
GBP
|
— | — | — | — | — | — | — | — | — |