Statement Of Changes In Equity [Abstract]
| Concept |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 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 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||||||||||||||||||||||||
| Equity |
1,436,900,000
GBP
|
— | — | — | — | — | — |
23 1.4
GBP
|
1 .0
GBP
|
1,113,000,000
GBP
|
5. 5
GBP
|
86 .0
GBP
|
3,100,000
GBP
|
3 .1
GBP
|
— | — |
9 5 7. 6
GBP
|
700,000
GBP
|
— | — |
1, 261. 3
GBP
|
— |
3 . 5
GBP
|
66,200,000
GBP
|
— | — |
3 .1
GBP
|
— |
2 31.4
GBP
|
5,800,000
GBP
|
— | — |
88 2.6
GBP
|
1. 9
GBP
|
6,000,000
GBP
|
3 .1
GBP
|
9 8.0
GBP
|
23 1.4
GBP
|
1 , 2 1 9.7
GBP
|
0. 5
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — |
–
GBP
|
4 01 . 5
GBP
|
401 . 5
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
34 6.9
GBP
|
346 .9
GBP
|
— | — | — | — | — | — | — | — |
| Other comprehensive income | — |
–
GBP
|
32,900,000
GBP
|
12 .7
GBP
|
400,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
19. 8
GBP
|
— | — |
–
GBP
|
1 .6
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
3 1. 8
GBP
|
— |
–
GBP
|
— | — |
3 4. 4
GBP
|
1. 0
GBP
|
— | — | — | — | — | — | — | — |
| Comprehensive income | — |
–
GBP
|
434,400,000
GBP
|
414 . 2
GBP
|
400,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
19. 8
GBP
|
— | — |
–
GBP
|
1 .6
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
3 1.8
GBP
|
— |
–
GBP
|
— | — |
3 12. 5
GBP
|
345 .9
GBP
|
— | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — |
–
GBP
|
78. 6
GBP
|
78 .6
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
79,000,000
GBP
|
79,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — |
–
GBP
|
10,600,000
GBP
|
10,600,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
9,100,000
GBP
|
9,100,000
GBP
|
— | — | — | — | — | — | — | — |