Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
21 .6
GBP
|
20,700,000
GBP
|
— |
| Investment property [abstract] | |||
| Investment property |
34,100,000
GBP
|
37 .9
GBP
|
— |
| Miscellaneous non-current assets [abstract] | |||
| Non-current net defined benefit asset |
100,000
GBP
|
500,000
GBP
|
— |
| Non-current derivative financial assets |
5,900,000
GBP
|
1. 0
GBP
|
— |
| Trade and other current receivables [abstract] | |||
| Current receivables due from related parties |
100,000
GBP
|
4,500,000
GBP
|
— |
| Other current receivables |
7 1. 2
GBP
|
245,300,000
GBP
|
— |
| Categories of non-current financial assets [abstract] | |||
| Non-current financial assets at fair value through profit or loss [abstract] | |||
| Non-current financial assets at fair value through profit or loss |
3,499,400,000
GBP
|
3,586,300,000
GBP
|
— |
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
204,300,000
GBP
|
21 8.0
GBP
|
325,900,000
GBP
|
| Miscellaneous current assets [abstract] | |||
| Current derivative financial assets |
65,400,000
GBP
|
57 .3
GBP
|
— |
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
137 .9
GBP
|
1 34.4
GBP
|
— |
| Current borrowings and current portion of non-current borrowings [abstract] | |||
| Current borrowings |
142,900,000
GBP
|
236,200,000
GBP
|
— |
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other current payables [abstract] | |||
| Current payables to related parties |
100,000
GBP
|
100,000
GBP
|
— |
| Other current payables |
39,200,000
GBP
|
63,500,000
GBP
|
— |
| Miscellaneous non-current liabilities [abstract] | |||
| Non-current derivative financial liabilities |
0
GBP
|
–
GBP
|
— |
| Miscellaneous current liabilities [abstract] | |||
| Current derivative financial liabilities |
2,800,000
GBP
|
1 0.4
GBP
|
— |
| Issued capital [abstract] | |||
| Issued capital |
1 56.8
GBP
|
156,800,000
GBP
|
— |
| Retained earnings [abstract] | |||
| Retained earnings |
32,200,000
GBP
|
29,100,000
GBP
|
— |
| Accumulated other comprehensive income [abstract] | |||
| Revaluation surplus |
1 0.3
GBP
|
9,400,000
GBP
|
— |
| Miscellaneous equity [abstract] | |||
| Capital redemption reserve |
36,300,000
GBP
|
36,300,000
GBP
|
— |
| Capital reserve |
3,393,100,000
GBP
|
3,548,900,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||
| Assets |
3,902,100,000
GBP
|
4,1 7 1 .5
GBP
|
— |
| Assets (liabilities) |
3,573,300,000
GBP
|
3,721 .7
GBP
|
— |
| Net current assets (liabilities) [abstract] | |||
| Current assets |
341 .0
GBP
|
525,100,000
GBP
|
— |
| Current liabilities |
1 85.0
GBP
|
31 0.2
GBP
|
— |
| Current assets (liabilities) |
156,000,000
GBP
|
21 4.9
GBP
|
— |
| Assets less current liabilities [abstract] | |||
| Assets less current liabilities |
3,71 7 .1
GBP
|
3,861 .3
GBP
|
— |