Statement Of Changes In Equity [Abstract]
| Concept |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 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 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||||||||
| Equity |
5,87 7
GBP
|
— |
207,000,000
GBP
|
7,000,000
GBP
|
— | — | — |
14 9
GBP
|
— | — | — |
12 9
GBP
|
640,000,000
GBP
|
5,02 1
GBP
|
280,000,000
GBP
|
5,66 3
GBP
|
— | — |
5,77 5
GBP
|
17 1
GBP
|
1,09 4
GBP
|
— |
207,000,000
GBP
|
— |
6,000,000
GBP
|
7,856,000,000
GBP
|
— | — | — | — |
7,64 3
GBP
|
640,000,000
GBP
|
— |
305,000,000
GBP
|
— | — |
4, 970
GBP
|
6, 810
GBP
|
306,000,000
GBP
|
3,000,000
GBP
|
–
GBP
|
1,064,000,000
GBP
|
640,000,000
GBP
|
170,000,000
GBP
|
6, 813
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — |
–
GBP
|
— | — |
–
GBP
|
54 9
GBP
|
1,000,000
GBP
|
— |
5 61
GBP
|
11,000,000
GBP
|
–
GBP
|
— | — | — | — | — |
561,000,000
GBP
|
–
GBP
|
— | — | — |
–
GBP
|
— |
994,000,000
GBP
|
— | — |
–
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
— | — |
–
GBP
|
— |
995,000,000
GBP
|
99 4
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income | — |
–
GBP
|
— | — |
41,000,000
GBP
|
780,000,000
GBP
|
–
GBP
|
— |
8 21
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
780,000,000
GBP
|
–
GBP
|
— | — | — |
22,000,000
GBP
|
— |
141,000,000
GBP
|
— | — |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
— |
141,000,000
GBP
|
119,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Comprehensive income | — |
–
GBP
|
— | — |
41,000,000
GBP
|
1, 3 29
GBP
|
1,000,000
GBP
|
— |
1, 382
GBP
|
11,000,000
GBP
|
–
GBP
|
— | — | — | — | — |
1, 341
GBP
|
–
GBP
|
— | — | — |
22,000,000
GBP
|
— |
1,135,000,000
GBP
|
— | — |
–
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
— | — |
–
GBP
|
— |
1,136,000,000
GBP
|
1,113,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Issue of equity | — |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
–
GBP
|
–
GBP
|
— | — | — |
–
GBP
|
— |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
— |
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — |
–
GBP
|
— | — |
–
GBP
|
3 07
GBP
|
–
GBP
|
— |
307,000,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
307,000,000
GBP
|
–
GBP
|
— | — | — |
–
GBP
|
— |
3 08
GBP
|
— | — |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
— |
308,000,000
GBP
|
3 08
GBP
|
— | — | — | — | — | — | — | — | — |
| Increase (decrease) through other changes, equity | — |
–
GBP
|
— | — |
1 7
GBP
|
6,000,000
GBP
|
–
GBP
|
— |
2 3
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
6,000,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |