Statement Of Comprehensive Income [Abstract]
| Concept |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
2023-02-01 to 2024-01-31 |
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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||
| Profit (loss) | — | — | — | — |
113,000,000
GBP
|
— | — | — | — | — | — | — | — |
273,100,000
GBP
|
— | — |
| Other comprehensive income [abstract] | ||||||||||||||||
| Components of other comprehensive income that will not be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans | — | — | — | — |
41,100,000
GBP
|
— | — | — | — | — | — | — | — |
19,100,000
GBP
|
— | — |
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||
| Cash flow hedges [abstract] | ||||||||||||||||
| Gains (losses) on cash flow hedges, before tax | — | — | — | — |
1,300,000
GBP
|
— | — | — | — | — | — | — | — |
2,000,000
GBP
|
— | — |
| Reclassification adjustments on cash flow hedges, before tax | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — |
300,000
GBP
|
— | — |
| Other comprehensive income, before tax, cash flow hedges | — | — | — | — |
300,000
GBP
|
— | — | — | — | — | — | — | — |
1,700,000
GBP
|
— | — |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — | — |
10,300,000
GBP
|
— | — | — | — | — | — | — | — |
4,800,000
GBP
|
— | — |
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract] | ||||||||||||||||
| Income tax relating to cash flow hedges included in other comprehensive income | — | — | — | — |
600,000
GBP
|
— | — | — | — | — | — | — | — |
800,000
GBP
|
— | — |
| Other comprehensive income | — | — | — | — |
30,500,000
GBP
|
— | — | — | — | — | — | — | — |
16,800,000
GBP
|
— | — |
| Comprehensive income |
–
GBP
|
143,800,000
GBP
|
–
GBP
|
300,000
GBP
|
143,500,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
2,500,000
GBP
|
–
GBP
|
–
GBP
|
287,400,000
GBP
|
289,900,000
GBP
|
–
GBP
|
–
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — |
143,500,000
GBP
|
— | — | — | — | — | — | — | — |
289,900,000
GBP
|
— | — |