Statement Of Changes In Equity [Abstract]
| Concept |
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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||
| Statement of changes in equity [line items] | |||||||||||||
| Dividends recognised as distributions to owners of parent | — | — |
122,000,000
GBP
|
— |
122,000,000
GBP
|
— | — | — |
139,000,000
GBP
|
139,000,000
GBP
|
— | — | — |
| Increase (decrease) through transfer to statutory reserve, equity |
nil
GBP
|
— | — | — | — | — |
10,000,000
GBP
|
10,000,000
GBP
|
— |
10,000,000
GBP
|
— | — |
nil
GBP
|
| Increase (decrease) through exercise of options, equity | — | — |
2,000,000
GBP
|
2,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Decrease (increase) through tax on share-based payment transactions, equity | — | — |
2,000,000
GBP
|
— |
2,000,000
GBP
|
— | — | — |
5,000,000
GBP
|
5,000,000
GBP
|
3,000,000
GBP
|
3,000,000
GBP
|
— |
| Share issue related cost | — |
16,000,000
GBP
|
16,000,000
GBP
|
— | — |
16,000,000
GBP
|
— | — | — | — | — | — | — |