Profit Or Loss [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 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Profit or loss [abstract] | ||||||||||||
| Profit (loss) [abstract] | ||||||||||||
| Tax expense (income) | — | — |
492,000,000
GBP
|
— | — |
121,000,000
GBP
|
— | — | — | — |
268,000,000
GBP
|
— |
| Profit (loss) from continuing operations | — | — |
1,353,000,000
GBP
|
— | — |
439,000,000
GBP
|
— | — | — | — |
703,000,000
GBP
|
— |
| Profit (loss) from discontinued operations | — | — |
31,000,000
GBP
|
— | — |
32,000,000
GBP
|
— | — | — | — |
30,000,000
GBP
|
— |
| Profit (loss) |
19,000,000
GBP
|
1,365,000,000
GBP
|
1,384,000,000
GBP
|
1,365,000,000
GBP
|
452,000,000
GBP
|
471,000,000
GBP
|
19,000,000
GBP
|
452,000,000
GBP
|
714,000,000
GBP
|
714,000,000
GBP
|
733,000,000
GBP
|
19,000,000
GBP
|
| Profit (loss), attributable to [abstract] | ||||||||||||
| Profit (loss), attributable to owners of parent | — | — |
1,365,000,000
GBP
|
— | — |
452,000,000
GBP
|
— | — | — | — |
714,000,000
GBP
|
— |
| Profit (loss), attributable to non-controlling interests | — | — |
19,000,000
GBP
|
— | — |
19,000,000
GBP
|
— | — | — | — |
19,000,000
GBP
|
— |