Statement Of Changes In Equity [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 |
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 changes in equity [abstract] | ||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||
| Increase (decrease) through exercise of options, equity |
–
GBP
|
–
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
–
GBP
|
700,000
GBP
|
300,000
GBP
|
100,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
100,000
GBP
|
–
GBP
|
–
GBP
|
200,000
GBP
|
| Decrease (increase) through tax on share-based payment transactions, equity |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
200,000
GBP
|
200,000
GBP
|
200,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
200,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
| Increase (decrease) through transactions with owners, equity |
–
GBP
|
–
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
–
GBP
|
4,500,000
GBP
|
5,500,000
GBP
|
6,700,000
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
5,500,000
GBP
|
–
GBP
|
–
GBP
|
200,000
GBP
|