Statement Of Changes In Equity [Abstract]
| Concept |
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 |
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 |
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 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 | — |
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
|
29,000,000
GBP
|
2,345,000,000
GBP
|
–
GBP
|
221,000,000
GBP
|
148,000,000
GBP
|
2,685,000,000
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) |
–
GBP
|
— | — | — | — |
–
GBP
|
–
GBP
|
276,000,000
GBP
|
— |
–
GBP
|
276,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
101,000,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
101,000,000
GBP
|
— | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — | — | — |
47,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
189,000,000
GBP
|
— | — | — | — | — | — | — |
| Comprehensive income |
–
GBP
|
— | — | — | — |
–
GBP
|
–
GBP
|
164,000,000
GBP
|
— |
65,000,000
GBP
|
229,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
41,000,000
GBP
|
47,000,000
GBP
|
–
GBP
|
— | — | — | — | — |
88,000,000
GBP
|
— | — | — | — | — | — | — |
| Dividends recognised as distributions to owners |
–
GBP
|
— | — | — | — |
–
GBP
|
–
GBP
|
141,000,000
GBP
|
— |
–
GBP
|
141,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
139,000,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
139,000,000
GBP
|
— | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
–
GBP
|
— | — | — | — |
–
GBP
|
–
GBP
|
18,000,000
GBP
|
— |
–
GBP
|
1 8
GBP
|
— |
–
GBP
|
–
GBP
|
15,000,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
15,000,000
GBP
|
— | — | — | — | — | — | — |