Statement Of Changes In Equity [Abstract]
| Concept |
As at 2023-01-31 |
As at 2023-01-31 |
As at 2023-01-31 |
2022-02-01 to 2023-01-31 |
2022-02-01 to 2023-01-31 |
As at 2023-01-31 |
As at 2023-01-31 |
As at 2023-01-31 |
2022-02-01 to 2023-01-31 |
2022-02-01 to 2023-01-31 |
2022-02-01 to 2023-01-31 |
2022-02-01 to 2023-01-31 |
As at 2023-01-31 |
2022-02-01 to 2023-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||
| Equity |
369,500,000
GBP
|
8,900,000
GBP
|
12,100,000
GBP
|
— | — |
21,100,000
GBP
|
3,200,000
GBP
|
648,300,000
GBP
|
— | — | — | — |
293,500,000
GBP
|
— |
21,100,000
GBP
|
700,000
GBP
|
648,300,000
GBP
|
— | — | — |
22,400,000
GBP
|
— |
7,400,000
GBP
|
— | — | — |
800,000
GBP
|
652,900,000
GBP
|
1,900,000
GBP
|
648,300,000
GBP
|
200,000
GBP
|
21,000,000
GBP
|
680,700,000
GBP
|
5,800,000
GBP
|
7,300,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||
| Profit (loss) | — | — | — | — | — | — | — | — | — | — |
259,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
28,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — | — | — |
28,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
3,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
| Comprehensive income | — | — | — |
273,500,000
GBP
|
–
GBP
|
— | — | — |
–
GBP
|
2,500,000
GBP
|
287,300,000
GBP
|
–
GBP
|
— |
11,300,000
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
1,200,000
GBP
|
— |
24,400,000
GBP
|
— |
31,300,000
GBP
|
–
GBP
|
8,100,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Issue of equity | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
–
GBP
|
100,000
GBP
|
–
GBP
|
— |
–
GBP
|
— |
100,000
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — | — |
–
GBP
|
3,900,000
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
3,900,000
GBP
|
–
GBP
|
— |
–
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
— |
3,400,000
GBP
|
3,400,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |