Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-03-31 |
As at 2021-03-31 |
As at 2020-03-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
710,600,000
GBP
|
734,400,000
GBP
|
840,900,000
GBP
|
| Intangible assets and goodwill [abstract] | |||
| Intangible assets other than goodwill [abstract] | |||
| Intangible assets other than goodwill |
175,700,000
GBP
|
199,900,000
GBP
|
332,900,000
GBP
|
| Goodwill |
782,400,000
GBP
|
956,300,000
GBP
|
2,381,300,000
GBP
|
| Investments accounted for using equity method [abstract] | |||
| Investments accounted for using equity method |
54,300,000
GBP
|
73,500,000
GBP
|
161,900,000
GBP
|
| Trade and other non-current receivables [abstract] | |||
| Non-current receivables due from related parties |
12,100,000
GBP
|
42,100,000
GBP
|
48,600,000
GBP
|
| Trade and other non-current receivables |
9,700,000
GBP
|
26,700,000
GBP
|
25,900,000
GBP
|
| Miscellaneous non-current assets [abstract] | |||
| Non-current net defined benefit asset |
300,900,000
GBP
|
46,800,000
GBP
|
298,400,000
GBP
|
| Non-current derivative financial assets |
–
GBP
|
4,300,000
GBP
|
14,600,000
GBP
|
| Non-current finance lease receivables |
24,100,000
GBP
|
12,900,000
GBP
|
6,900,000
GBP
|
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
488,800,000
GBP
|
435,700,000
GBP
|
480,700,000
GBP
|
| Current prepayments and current accrued income including current contract assets [abstract] | |||
| Current accrued income including current contract assets [abstract] | |||
| Current contract assets |
299,300,000
GBP
|
276,400,000
GBP
|
319,200,000
GBP
|
| Categories of non-current financial assets [abstract] | |||
| Non-current financial assets |
10,000,000
GBP
|
11,200,000
GBP
|
12,800,000
GBP
|
| Classes of current inventories [abstract] | |||
| Current inventories |
142,700,000
GBP
|
153,000,000
GBP
|
191,600,000
GBP
|
| Classes of current inventories, alternative [abstract] | |||
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
1,146,300,000
GBP
|
904,800,000
GBP
|
1,845,900,000
GBP
|
| Miscellaneous current assets [abstract] | |||
| Current derivative financial assets |
11,400,000
GBP
|
8,200,000
GBP
|
122,200,000
GBP
|
| Current finance lease receivables |
23,300,000
GBP
|
26,700,000
GBP
|
31,700,000
GBP
|
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
847,700,000
GBP
|
1,323,800,000
GBP
|
2,055,000,000
GBP
|
| Current borrowings and current portion of non-current borrowings [abstract] | |||
| Current borrowings |
863,400,000
GBP
|
383,700,000
GBP
|
987,900,000
GBP
|
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other non-current payables [abstract] | |||
| Trade and other non-current payables |
1,000,000
GBP
|
1,900,000
GBP
|
2,100,000
GBP
|
| Trade and other current payables [abstract] | |||
| Current accruals and current deferred income including current contract liabilities [abstract] | |||
| Current deferred income including current contract liabilities [abstract] | |||
| Current contract liabilities [abstract] | |||
| Current contract liabilities |
518,300,000
GBP
|
396,500,000
GBP
|
243,200,000
GBP
|
| Trade and other current payables |
888,100,000
GBP
|
1,110,200,000
GBP
|
1,058,000,000
GBP
|
| Miscellaneous non-current liabilities [abstract] | |||
| Non-current net defined benefit liability |
109,300,000
GBP
|
325,700,000
GBP
|
200,200,000
GBP
|
| Non-current derivative financial liabilities |
59,300,000
GBP
|
51,000,000
GBP
|
35,500,000
GBP
|
| Miscellaneous current liabilities [abstract] | |||
| Current derivative financial liabilities |
34,800,000
GBP
|
13,900,000
GBP
|
27,700,000
GBP
|
| Issued capital [abstract] | |||
| Issued capital |
303,400,000
GBP
|
303,400,000
GBP
|
303,400,000
GBP
|
| Retained earnings [abstract] | |||
| Retained earnings |
1,241,400,000
GBP
|
1,671,700,000
GBP
|
488,900,000
GBP
|
| Net assets (liabilities) [abstract] | |||
| Assets |
4,598,300,000
GBP
|
4,610,900,000
GBP
|
7,851,100,000
GBP
|
| Liabilities |
3,896,800,000
GBP
|
4,381,900,000
GBP
|
5,499,300,000
GBP
|
| Net current assets (liabilities) [abstract] | |||
| Current assets |
2,137,200,000
GBP
|
1,854,800,000
GBP
|
3,048,500,000
GBP
|
| Current liabilities |
2,480,300,000
GBP
|
2,111,900,000
GBP
|
2,591,600,000
GBP
|
| Assets less current liabilities [abstract] |