Statement Of Changes In Equity [Abstract]
| Concept |
As at 2025-03-31 |
As at 2025-03-31 |
2024-04-01 to 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
2024-04-01 to 2025-03-31 |
As at 2025-03-31 |
2024-04-01 to 2025-03-31 |
As at 2025-03-31 |
2024-04-01 to 2025-03-31 |
2024-04-01 to 2025-03-31 |
2024-04-01 to 2025-03-31 |
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 |
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 |
As at 2023-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||||||||||||||
| Equity |
71,200,000
GBP
|
1,502,200,000
GBP
|
— |
295,600,000
GBP
|
0 .3
GBP
|
— |
192. 1
GBP
|
— |
943,600,000
GBP
|
— | — | — | — |
93,000,000
GBP
|
977 .3
GBP
|
296,600,000
GBP
|
191,900,000
GBP
|
9 .9
GBP
|
— |
1,548,900,000
GBP
|
— | — | — | — |
1,787,700,000
GBP
|
295,500,000
GBP
|
191,600,000
GBP
|
9,900,000
GBP
|
1,219,500,000
GBP
|
91. 0
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) | — | — |
5,400,000
GBP
|
— | — |
5,400,000
GBP
|
— |
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
192,500,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
192,500,000
GBP
|
— | — | — | — | — | — |
| Other comprehensive income | — | — |
200,000
GBP
|
— | — |
–
GBP
|
— |
–
GBP
|
— |
–
GBP
|
–
GBP
|
200,000
GBP
|
1,300,000
GBP
|
— | — | — | — | — |
1,300,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — |
| Comprehensive income | — | — |
5,200,000
GBP
|
— | — |
5,400,000
GBP
|
— |
–
GBP
|
— |
–
GBP
|
–
GBP
|
200,000
GBP
|
1,300,000
GBP
|
— | — | — | — | — |
191,200,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
192,500,000
GBP
|
— | — | — | — | — | — |
| Dividends recognised as distributions to owners | — | — |
54,500,000
GBP
|
— | — |
54,500,000
GBP
|
— |
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — |
50,600,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
50,600,000
GBP
|
— | — | — | — | — | — |
| Increase (decrease) through treasury share transactions, equity | — | — |
–
GBP
|
— | — |
9,300,000
GBP
|
— |
9. 3
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — |
2,300,000
GBP
|
— | — |
3,500,000
GBP
|
— |
–
GBP
|
— |
200,000
GBP
|
1,000,000
GBP
|
0 .4
GBP
|
700,000
GBP
|
— | — | — | — | — |
3 .0
GBP
|
— |
1 .1
GBP
|
0. 3
GBP
|
— |
900,000
GBP
|
— | — | — | — | — | — |