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 |
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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||||||||||||||
| Equity | — |
36,000,000
GBP
|
1,998,000,000
GBP
|
148,000,000
GBP
|
215,000,000
GBP
|
17,000,000
GBP
|
— |
2,380,000,000
GBP
|
— | — | — | — | — |
2,539,000,000
GBP
|
148,000,000
GBP
|
215,000,000
GBP
|
19,000,000
GBP
|
— | — | — |
2,077,000,000
GBP
|
— | — |
118,000,000
GBP
|
50,000,000
GBP
|
24,000,000
GBP
|
218,000,000
GBP
|
148,000,000
GBP
|
2,049,000,000
GBP
|
2,441,000,000
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) |
–
GBP
|
— | — | — | — | — |
108,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
108,000,000
GBP
|
–
GBP
|
— | — | — | — |
–
GBP
|
276,000,000
GBP
|
–
GBP
|
— |
–
GBP
|
276,000,000
GBP
|
— | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — |
132,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
47,000,000
GBP
|
— | — | — | — | — | — | — |
| Comprehensive income |
82,000,000
GBP
|
— | — | — | — | — |
24,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
58,000,000
GBP
|
–
GBP
|
— | — | — | — |
–
GBP
|
164,000,000
GBP
|
–
GBP
|
— |
65,000,000
GBP
|
229,000,000
GBP
|
— | — | — | — | — | — | — |
| Dividends recognised as distributions to owners |
–
GBP
|
— | — | — | — | — |
141,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
141,000,000
GBP
|
–
GBP
|
— | — | — | — |
–
GBP
|
141,000,000
GBP
|
–
GBP
|
— |
–
GBP
|
141,000,000
GBP
|
— | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
–
GBP
|
— | — | — | — | — |
17,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
17,000,000
GBP
|
–
GBP
|
— | — | — | — |
–
GBP
|
18,000,000
GBP
|
–
GBP
|
— |
–
GBP
|
18,000,000
GBP
|
— | — | — | — | — | — | — |