Statement Of Changes In Equity [Abstract]
| Concept |
2023-04-01 to 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
2023-04-01 to 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
2023-04-01 to 2024-03-31 |
As at 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
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 |
2022-04-01 to 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 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
As at 2023-03-31 |
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 |
As at 2022-03-31 |
As at 2022-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||
| Equity | — |
23,000,000
GBP
|
6,402,000,000
GBP
|
5,980,000,000
GBP
|
— |
45,000,000
GBP
|
319,000,000
GBP
|
80,000,000
GBP
|
— |
6,447,000,000
GBP
|
— | — | — | — | — |
7,005,000,000
GBP
|
7,072,000,000
GBP
|
318,000,000
GBP
|
80,000,000
GBP
|
— | — | — | — |
6,594,000,000
GBP
|
67,000,000
GBP
|
— | — |
13,000,000
GBP
|
9,000,000
GBP
|
7,917,000,000
GBP
|
7,511,000,000
GBP
|
317,000,000
GBP
|
80,000,000
GBP
|
7,991,000,000
GBP
|
74,000,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||
| Profit (loss) | — | — | — | — | — | — | — | — |
341,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
622,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — |
2,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
10,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Comprehensive income |
–
GBP
|
— | — | — |
321,000,000
GBP
|
— | — | — |
343,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
321,000,000
GBP
|
22,000,000
GBP
|
629,000,000
GBP
|
— | — | — | — |
–
GBP
|
629,000,000
GBP
|
–
GBP
|
3,000,000
GBP
|
— | — |
–
GBP
|
632,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners |
–
GBP
|
— | — | — |
291,000,000
GBP
|
— | — | — |
291,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
291,000,000
GBP
|
–
GBP
|
290,000,000
GBP
|
— | — | — | — |
–
GBP
|
290,000,000
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
290,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
10,000,000
GBP
|
— | — | — |
9,000,000
GBP
|
— | — | — |
9,000,000
GBP
|
— |
1,000,000
GBP
|
–
GBP
|
2,000,000
GBP
|
–
GBP
|
7,000,000
GBP
|
— | — | — | — |
–
GBP
|
2,000,000
GBP
|
1,000,000
GBP
|
–
GBP
|
— | — |
4,000,000
GBP
|
7,000,000
GBP
|
— | — | — | — | — | — | — | — |