Analysis Of Income And Expense [Abstract]
| Concept |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Analysis of income and expense [abstract] | ||||||||||||||||||||||||
| Revenue [abstract] | ||||||||||||||||||||||||
| Interest income | — | — | — | — | — | — | — | — | — | — |
746,800,000
GBP
|
— | — |
7 11 .9
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Revenue | — | — | — | — | — | — | — | — | — | — |
6 2 9.0
GBP
|
— | — |
50 8.6
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Material income and expense [abstract] | ||||||||||||||||||||||||
| Gains (losses) on disposals of investments [abstract] | ||||||||||||||||||||||||
| Gains (losses) on disposals of investments | — | — | — | — | — | — | — | — | — | — |
4,000,000
GBP
|
— | — |
20,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Interest expense | — | — | — | — | — | — | — | — | — | — |
1 59 . 2
GBP
|
— | — |
239 .7
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Interest income (expense) | — | — | — | — | — | — | — | — | — | — |
5 8 7. 6
GBP
|
— | — |
47 2 . 2
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Miscellaneous other comprehensive income [abstract] | ||||||||||||||||||||||||
| Other comprehensive income, before tax, exchange differences on translation of foreign operations and hedges of net investments in foreign operations [abstract] | ||||||||||||||||||||||||
| Other comprehensive income, before tax, exchange differences on translation of foreign operations | — | — | — | — | — | — | — | — | — | — |
0 .1
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Income tax relating to components of other comprehensive income [abstract] | ||||||||||||||||||||||||
| Income tax relating to components of other comprehensive income |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
500,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
500,000
GBP
|
–
GBP
|
–
GBP
|
0. 5
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
500,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
| Comprehensive income, continuing and discontinued operations [abstract] | ||||||||||||||||||||||||
| Comprehensive income |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
100,000
GBP
|
–
GBP
|
0 .4
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
344. 8
GBP
|
345,300,000
GBP
|
–
GBP
|
196. 8
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
196 .3
GBP
|
500,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||||||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — | — | — | — | — |
3 4 0.1
GBP
|
— | — |
191. 3
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Comprehensive income attributable to non-controlling interests, continuing and discontinued operations [abstract] | ||||||||||||||||||||||||
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — | — | — | — | — | — |
4,700,000
GBP
|
— | — |
5,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — |