Statement Of Comprehensive Income [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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||||
| Profit (loss) |
4 .9
GBP
|
–
GBP
|
117 . 0
GBP
|
–
GBP
|
224,400,000
GBP
|
10 2 . 5
GBP
|
–
GBP
|
–
GBP
|
121. 9
GBP
|
11 7. 0
GBP
|
1 3 9 .1
GBP
|
1 42.0
GBP
|
93,800,000
GBP
|
2 3 2 .9
GBP
|
–
GBP
|
–
GBP
|
2 .9
GBP
|
–
GBP
|
1 42.0
GBP
|
–
GBP
|
| Other comprehensive income [abstract] | ||||||||||||||||||||
| Components of other comprehensive income that will not be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||||
| Other comprehensive income, before tax, gains (losses) from investments in equity instruments | — | — | — | — | — | — | — | — |
1. 6
GBP
|
— |
2,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans | — | — | — | — | — | — | — | — |
58,200,000
GBP
|
— |
14 . 8
GBP
|
— | — | — | — | — | — | — | — | — |
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||||
| Exchange differences on translation [abstract] | ||||||||||||||||||||
| Reclassification adjustments on exchange differences on translation of foreign operations, before tax | — | — | — | — | — | — | — | — |
10 8 . 2
GBP
|
— |
8. 4
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income, before tax, exchange differences on translation of foreign operations | — | — | — | — | — | — | — | — |
10 4 . 3
GBP
|
— |
4 2 . 8
GBP
|
— | — | — | — | — | — | — | — | — |
| Cash flow hedges [abstract] | ||||||||||||||||||||
| Other comprehensive income, before tax, cash flow hedges | — | — | — | — | — | — | — | — |
18 . 5
GBP
|
— |
4,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income |
0. 8
GBP
|
22 .0
GBP
|
7 9. 8
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
7 9. 0
GBP
|
5 7. 8
GBP
|
4 6 .9
GBP
|
12. 0
GBP
|
— | — |
59,300,000
GBP
|
–
GBP
|
400,000
GBP
|
–
GBP
|
4 7. 3
GBP
|
–
GBP
|
| Comprehensive income |
4 .1
GBP
|
22,000,000
GBP
|
19 6 . 8
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
2 0 0 .9
GBP
|
174 . 8
GBP
|
18 6 . 0
GBP
|
13 0 . 0
GBP
|
— | — |
59,300,000
GBP
|
–
GBP
|
3,300,000
GBP
|
–
GBP
|
18 9. 3
GBP
|
–
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — | — | — |
19 6 . 8
GBP
|
— |
18 9. 3
GBP
|
— | — | — | — | — | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — | — | — | — |
4 .1
GBP
|
— |
3,300,000
GBP
|
— | — | — | — | — | — | — | — | — |