Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-03-31 |
As at 2021-03-31 |
|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||
| Property, plant and equipment [abstract] | ||
| Property, plant and equipment |
12,147,500,000
GBP
|
11,799,000,000
GBP
|
| Intangible assets and goodwill [abstract] | ||
| Intangible assets and goodwill |
160,800,000
GBP
|
181,100,000
GBP
|
| Trade and other non-current receivables [abstract] | ||
| Trade and other non-current receivables |
81,700,000
GBP
|
86,700,000
GBP
|
| Miscellaneous non-current assets [abstract] | ||
| Non-current net defined benefit asset |
1,016,800,000
GBP
|
689,000,000
GBP
|
| Non-current derivative financial assets |
399,400,000
GBP
|
410,300,000
GBP
|
| Trade and other current receivables [abstract] | ||
| Trade and other current receivables |
222,700,000
GBP
|
229,200,000
GBP
|
| Classes of current inventories [abstract] | ||
| Current inventories |
17,800,000
GBP
|
18,300,000
GBP
|
| Classes of current inventories, alternative [abstract] | ||
| Cash and cash equivalents [abstract] | ||
| Cash and cash equivalents |
240,900,000
GBP
|
744,100,000
GBP
|
| Miscellaneous current assets [abstract] | ||
| Current derivative financial assets |
58,000,000
GBP
|
14,400,000
GBP
|
| Borrowings [abstract] | ||
| Non-current portion of non-current borrowings |
7,671,000,000
GBP
|
7,797,000,000
GBP
|
| Current borrowings and current portion of non-current borrowings [abstract] | ||
| Current borrowings |
308,800,000
GBP
|
654,800,000
GBP
|
| Non-current portion of non-current borrowings, by type [abstract] | ||
| Trade and other non-current payables [abstract] | ||
| Trade and other non-current payables |
835,200,000
GBP
|
798,300,000
GBP
|
| Trade and other current payables [abstract] | ||
| Trade and other current payables |
365,800,000
GBP
|
322,700,000
GBP
|
| Miscellaneous non-current liabilities [abstract] | ||
| Non-current derivative financial liabilities |
136,700,000
GBP
|
107,800,000
GBP
|
| Miscellaneous current liabilities [abstract] | ||
| Current derivative financial liabilities |
500,000
GBP
|
6,900,000
GBP
|
| Issued capital [abstract] | ||
| Issued capital |
499,800,000
GBP
|
499,800,000
GBP
|
| Retained earnings [abstract] | ||
| Retained earnings |
2,038,500,000
GBP
|
2,192,000,000
GBP
|
| Net assets (liabilities) [abstract] | ||
| Assets |
14,437,000,000
GBP
|
14,179,100,000
GBP
|
| Liabilities |
11,479,600,000
GBP
|
11,148,100,000
GBP
|
| Assets (liabilities) |
2,957,400,000
GBP
|
3,031,000,000
GBP
|
| Net current assets (liabilities) [abstract] | ||
| Current assets |
613,800,000
GBP
|
1,012,900,000
GBP
|
| Current liabilities |
688,600,000
GBP
|
995,500,000
GBP
|
| Assets less current liabilities [abstract] |