Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2025-03-31 |
As at 2024-03-31 |
As at 2023-03-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
16,000,000
GBP
|
19,000,000
GBP
|
— |
| Investment property [abstract] | |||
| Investment property |
6,130,000,000
GBP
|
5,229,000,000
GBP
|
— |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements [abstract] | |||
| Investments in joint ventures reported in separate financial statements |
2,462,000,000
GBP
|
2,429,000,000
GBP
|
— |
| Miscellaneous non-current assets [abstract] | |||
| Non-current derivative financial assets |
73,000,000
GBP
|
79,000,000
GBP
|
— |
| Other non-current assets |
8,729,000,000
GBP
|
7,810,000,000
GBP
|
— |
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
36,000,000
GBP
|
34,000,000
GBP
|
— |
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
57,000,000
GBP
|
88,000,000
GBP
|
125,000,000
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 |
22,000,000
GBP
|
–
GBP
|
— |
| Miscellaneous current assets [abstract] | |||
| Current derivative financial assets |
9,000,000
GBP
|
20,000,000
GBP
|
— |
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
2,417,000,000
GBP
|
2,202,000,000
GBP
|
— |
| Current borrowings and current portion of non-current borrowings [abstract] | |||
| Current borrowings |
311,000,000
GBP
|
10,000,000
GBP
|
— |
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other current payables [abstract] | |||
| Trade and other current payables |
263,000,000
GBP
|
260,000,000
GBP
|
— |
| Miscellaneous non-current liabilities [abstract] | |||
| Non-current derivative financial liabilities |
56,000,000
GBP
|
56,000,000
GBP
|
— |
| Other non-current liabilities |
107,000,000
GBP
|
121,000,000
GBP
|
— |
| Miscellaneous current liabilities [abstract] | |||
| Current derivative financial liabilities |
2,000,000
GBP
|
–
GBP
|
— |
| Issued capital [abstract] | |||
| Issued capital |
253,000,000
GBP
|
235,000,000
GBP
|
— |
| Retained earnings [abstract] | |||
| Retained earnings |
3,642,000,000
GBP
|
3,528,000,000
GBP
|
— |
| Miscellaneous equity [abstract] | |||
| Merger reserve |
213,000,000
GBP
|
213,000,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||
| Assets |
8,875,000,000
GBP
|
7,974,000,000
GBP
|
— |
| Liabilities |
3,165,000,000
GBP
|
2,662,000,000
GBP
|
— |
| Assets (liabilities) |
5,710,000,000
GBP
|
5,312,000,000
GBP
|
— |
| Net current assets (liabilities) [abstract] | |||
| Current assets |
146,000,000
GBP
|
164,000,000
GBP
|
— |
| Current liabilities |
582,000,000
GBP
|
278,000,000
GBP
|
— |
| Assets less current liabilities [abstract] |