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 |
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] | ||||||||
| Dividends recognised as distributions to owners of parent, relating to current year | — |
88,709,000
GBP
|
88,709,000
GBP
|
88,709,000
GBP
|
— | — | — | — |
| Increase (decrease) through exercise of options, equity |
3,584,000
GBP
|
3,584,000
GBP
|
— | — | — | — |
164,000
GBP
|
164,000
GBP
|
| Decrease (increase) through tax on share-based payment transactions, equity | — |
399,000
GBP
|
399,000
GBP
|
399,000
GBP
|
339,000
GBP
|
339,000
GBP
|
339,000
GBP
|
— |