Statement Of Changes In Equity [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
As at 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 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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||
| Equity | — |
53,400,000
GBP
|
34,500,000
GBP
|
–
GBP
|
— | — | — |
13,600,000
GBP
|
— |
5,300,000
GBP
|
38,700,000
GBP
|
— | — | — |
400,000
GBP
|
— |
4,400,000
GBP
|
29,500,000
GBP
|
4,400,000
GBP
|
— |
17,200,000
GBP
|
700,000
GBP
|
26,500,000
GBP
|
4,200,000
GBP
|
4,400,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||
| Profit (loss) |
6,500,000
GBP
|
— | — | — |
6,500,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
8,400,000
GBP
|
8,400,000
GBP
|
— |
–
GBP
|
— | — | — |
–
GBP
|
— | — | — | — | — |
| Other comprehensive income |
400,000
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
400,000
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
6,600,000
GBP
|
6,800,000
GBP
|
— |
200,000
GBP
|
— | — | — |
–
GBP
|
— | — | — | — | — |
| Comprehensive income |
6,100,000
GBP
|
— | — | — |
6,500,000
GBP
|
–
GBP
|
400,000
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
15,000,000
GBP
|
15,200,000
GBP
|
— |
200,000
GBP
|
— | — | — |
–
GBP
|
— | — | — | — | — |
| Issue of equity |
10,100,000
GBP
|
— | — | — |
–
GBP
|
9,200,000
GBP
|
–
GBP
|
— |
900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners |
2,500,000
GBP
|
— | — | — |
2,500,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
2,300,000
GBP
|
2,300,000
GBP
|
— |
–
GBP
|
— | — | — |
–
GBP
|
— | — | — | — | — |
| Increase (decrease) through treasury share transactions, equity |
800,000
GBP
|
— | — | — |
800,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
1,700,000
GBP
|
— | — | — |
1,700,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
800,000
GBP
|
800,000
GBP
|
— |
–
GBP
|
— | — | — |
–
GBP
|
— | — | — | — | — |