Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-01-31 |
As at 2021-01-31 |
As at 2020-01-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
646,500,000
GBP
|
660,200,000
GBP
|
— |
| Intangible assets and goodwill [abstract] | |||
| Intangible assets other than goodwill [abstract] | |||
| Intangible assets other than goodwill |
47,100,000
GBP
|
56,600,000
GBP
|
— |
| Goodwill |
718,600,000
GBP
|
718,600,000
GBP
|
— |
| Trade and other receivables [abstract] | |||
| Trade and other receivables |
169,500,000
GBP
|
183,100,000
GBP
|
— |
| Categories of financial assets [abstract] | |||
| Financial assets |
332,100,000
GBP
|
359,800,000
GBP
|
— |
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
255,700,000
GBP
|
166,900,000
GBP
|
139,100,000
GBP
|
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | |||
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners |
12,900,000
GBP
|
16,900,000
GBP
|
— |
| Miscellaneous assets [abstract] | |||
| Net defined benefit asset |
1,100,000
GBP
|
–
GBP
|
— |
| Trade and other payables [abstract] | |||
| Accruals and deferred income including contract liabilities [abstract] | |||
| Deferred income including contract liabilities [abstract] | |||
| Contract liabilities [abstract] | |||
| Contract liabilities |
114,600,000
GBP
|
82,200,000
GBP
|
— |
| Trade and other payables |
199,700,000
GBP
|
175,100,000
GBP
|
— |
| Categories of financial liabilities [abstract] | |||
| Financial liabilities |
936,200,000
GBP
|
826,600,000
GBP
|
— |
| Miscellaneous liabilities [abstract] | |||
| Net defined benefit liability |
–
GBP
|
4,300,000
GBP
|
— |
| Issued capital [abstract] | |||
| Issued capital |
21,100,000
GBP
|
21,000,000
GBP
|
— |
| Retained earnings [abstract] | |||
| Retained earnings |
22,400,000
GBP
|
200,000
GBP
|
— |
| Accumulated other comprehensive income [abstract] | |||
| Reserve of cash flow hedges |
700,000
GBP
|
1,900,000
GBP
|
— |
| Reserve of gains and losses on financial assets measured at fair value through other comprehensive income |
800,000
GBP
|
7,300,000
GBP
|
— |
| Miscellaneous equity [abstract] | |||
| Reserve of share-based payments |
7,400,000
GBP
|
5,800,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||
| Assets |
2,302,400,000
GBP
|
2,212,700,000
GBP
|
— |
| Liabilities |
1,649,500,000
GBP
|
1,532,000,000
GBP
|
— |
| Assets less current liabilities [abstract] |