Statement Of Changes In Equity [Abstract]
| Concept |
As at 2023-03-31 |
2022-04-01 to 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
2021-04-01 to 2022-03-31 |
As at 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
2021-04-01 to 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||
| Equity |
31,000,000
GBP
|
— |
16,844,000,000
GBP
|
790,000,000
GBP
|
719,000,000
GBP
|
108,000,000
GBP
|
43,000,000
GBP
|
— | — | — |
1,327,000,000
GBP
|
14,044,000,000
GBP
|
2,000,000
GBP
|
— | — | — |
43,000,000
GBP
|
— | — | — | — |
100,000,000
GBP
|
10,151,000,000
GBP
|
719,000,000
GBP
|
6,000,000
GBP
|
789,000,000
GBP
|
— |
12,754,000,000
GBP
|
1,125,000,000
GBP
|
33,000,000
GBP
|
34,000,000
GBP
|
43,000,000
GBP
|
64,000,000
GBP
|
6,733,000,000
GBP
|
916,000,000
GBP
|
9,164,000,000
GBP
|
719,000,000
GBP
|
788,000,000
GBP
|
5,000,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — |
4,064,000,000
GBP
|
— | — | — | — | — | — | — |
509,000,000
GBP
|
— | — | — | — |
4,573,000,000
GBP
|
— | — |
3,547,000,000
GBP
|
— | — |
466,000,000
GBP
|
— | — | — | — | — |
4,013,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
12,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Comprehensive income | — |
4,072,000,000
GBP
|
— | — | — | — | — |
4,000,000
GBP
|
— |
509,000,000
GBP
|
— | — | — | — |
4,585,000,000
GBP
|
— | — |
3,549,000,000
GBP
|
— |
1,000,000
GBP
|
466,000,000
GBP
|
— | — | — | — | — |
4,014,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Issue of equity | — | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — |
1,000,000
GBP
|
— | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — |
157,000,000
GBP
|
— | — | — | — | — | — | — |
328,000,000
GBP
|
— | — | — | — |
485,000,000
GBP
|
— | — |
113,000,000
GBP
|
— | — |
276,000,000
GBP
|
— | — | — | — | — |
389,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — | — | — | — | — | — | — | — | — | — | — | — |
19,000,000
GBP
|
19,000,000
GBP
|
18,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
18,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |