Statement Of Changes In Equity [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
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 |
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 |
2022-01-01 to 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 |
As at 2021-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||
| Equity | — |
456 .6
GBP
|
— | — |
3 40.0
GBP
|
— | — | — | — | — |
104,900,000
GBP
|
4 .0
GBP
|
— |
7. 7
GBP
|
452 . 6
GBP
|
41 3 . 2
GBP
|
— | — | — | — | — | — |
114 . 8
GBP
|
— |
3,500,000
GBP
|
2 8 7. 2
GBP
|
7. 7
GBP
|
409,700,000
GBP
|
— |
24 5 . 3
GBP
|
10 4.0
GBP
|
361,600,000
GBP
|
356 .9
GBP
|
4 .7
GBP
|
7. 6
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||
| Profit (loss) |
85. 8
GBP
|
— |
83 .8
GBP
|
–
GBP
|
— |
85. 8
GBP
|
2 .0
GBP
|
2,500,000
GBP
|
2. 5
GBP
|
83,800,000
GBP
|
— | — |
–
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
79 .6
GBP
|
75 .6
GBP
|
4,000,000
GBP
|
80. 3
GBP
|
— |
0 . 7
GBP
|
— | — | — | — |
75 .6
GBP
|
— | — | — | — | — | — |
| Other comprehensive income |
11 .3
GBP
|
— |
11 .0
GBP
|
9. 4
GBP
|
— | — |
0 . 3
GBP
|
— | — |
1. 6
GBP
|
— | — |
–
GBP
|
— | — | — |
–
GBP
|
7. 9
GBP
|
2,400,000
GBP
|
5 . 5
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
2,400,000
GBP
|
— | — | — | — | — | — |
| Comprehensive income |
74 . 5
GBP
|
— |
72 .8
GBP
|
9. 4
GBP
|
— | — |
1,700,000
GBP
|
— | — |
82 . 2
GBP
|
— | — |
–
GBP
|
— | — | — |
–
GBP
|
7. 9
GBP
|
82,000,000
GBP
|
70,100,000
GBP
|
4,000,000
GBP
|
— | — | — | — | — | — | — |
78 .0
GBP
|
— | — | — | — | — | — |
| Issue of equity |
1,900,000
GBP
|
— |
1,900,000
GBP
|
1,900,000
GBP
|
— | — |
–
GBP
|
— | — |
–
GBP
|
— | — |
–
GBP
|
— | — | — |
100,000
GBP
|
2,600,000
GBP
|
2 .7
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
2 .7
GBP
|
— | — | — | — | — | — |
| Dividends recognised as distributions to owners |
2 9. 4
GBP
|
— |
28 . 3
GBP
|
–
GBP
|
— | — |
1 .1
GBP
|
— | — |
28 . 3
GBP
|
— | — |
–
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
30 . 2
GBP
|
25 . 9
GBP
|
4 . 3
GBP
|
— | — | — | — | — | — | — |
2 5 . 9
GBP
|
— | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
3 .5
GBP
|
— |
3 . 5
GBP
|
2 . 4
GBP
|
— | — |
–
GBP
|
— | — |
1 .1
GBP
|
— | — |
–
GBP
|
— | — | — |
–
GBP
|
300,000
GBP
|
1 . 0
GBP
|
1,300,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
1 . 0
GBP
|
— | — | — | — | — | — |