Statement Of Changes In Equity [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
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 |
2021-01-01 to 2021-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||
| Increase (decrease) through acquisition of subsidiary, equity |
32,000,000
GBP
|
32,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Purchase of treasury shares |
2,057,000,000
GBP
|
— |
856,000,000
GBP
|
2,057,000,000
GBP
|
2,057,000,000
GBP
|
856,000,000
GBP
|
— |
929,000,000
GBP
|
2,054,000,000
GBP
|
2,054,000,000
GBP
|
2,054,000,000
GBP
|
929,000,000
GBP
|
1,423,000,000
GBP
|
698,000,000
GBP
|
698,000,000
GBP
|
1,423,000,000
GBP
|
1,423,000,000
GBP
|
| Cancellation of treasury shares | — | — | — | — | — | — |
906,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — |