Statement Of Changes In Equity [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
As at 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 |
As at 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 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 |
2022-01-01 to 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 |
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 | — |
246,800,000
GBP
|
8 4 .9
GBP
|
— | — | — |
2 9 3 .1
GBP
|
— |
0. 4
GBP
|
14 . 2
GBP
|
— |
24 .0
GBP
|
28 4. 0
GBP
|
— | — | — |
2 9 3 .1
GBP
|
22,200,000
GBP
|
4 8 .6
GBP
|
400,000
GBP
|
16,900,000
GBP
|
— | — | — |
35 . 6
GBP
|
28 8 .0
GBP
|
11 .1
GBP
|
1 9 .1
GBP
|
293,000,000
GBP
|
400,000
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) |
3 8. 3
GBP
|
— | — |
3 8 . 3
GBP
|
—
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
—
GBP
|
— | — |
—
GBP
|
6 .9
GBP
|
6. 9
GBP
|
— | — | — | — | — |
—
GBP
|
—
GBP
|
—
GBP
|
— | — | — | — | — | — |
| Comprehensive income |
41 .0
GBP
|
— | — |
3 8 .3
GBP
|
—
GBP
|
2. 7
GBP
|
— |
—
GBP
|
— | — |
—
GBP
|
— | — |
—
GBP
|
1 .1
GBP
|
6 .9
GBP
|
— | — | — | — | — |
—
GBP
|
—
GBP
|
5,800,000
GBP
|
— | — | — | — | — | — |
| Issue of equity |
—
GBP
|
— | — |
—
GBP
|
—
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
—
GBP
|
— | — |
—
GBP
|
0 .1
GBP
|
—
GBP
|
— | — | — | — | — |
—
GBP
|
0 .1
GBP
|
—
GBP
|
— | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
5,600,000
GBP
|
— | — |
—
GBP
|
—
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
5,600,000
GBP
|
— | — |
—
GBP
|
5,700,000
GBP
|
—
GBP
|
— | — | — | — | — |
5,700,000
GBP
|
—
GBP
|
—
GBP
|
— | — | — | — | — | — |