Statement Of Comprehensive Income [Abstract]
| Concept |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2021-05-01 to 2022-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
2020-05-01 to 2021-04-30 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||||||
| Profit (loss) |
–
GBP
|
35,000,000
GBP
|
315,000,000
GBP
|
–
GBP
|
280,000,000
GBP
|
280,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
280,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
28,000,000
GBP
|
222,000,000
GBP
|
194,000,000
GBP
|
194,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
194,000,000
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) from investments in equity instruments | — | — | — | — | — | — | — | — | — | — |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
3,000,000
GBP
|
3,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
3,000,000
GBP
|
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans |
–
GBP
|
— | — |
–
GBP
|
68,000,000
GBP
|
68,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
68,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
5,000,000
GBP
|
5,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
5,000,000
GBP
|
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||||||
| Exchange differences on translation [abstract] | ||||||||||||||||||||||
| Reclassification adjustments on exchange differences on translation of foreign operations, before tax |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
3,000,000
GBP
|
–
GBP
|
–
GBP
|
3,000,000
GBP
|
–
GBP
|
3,000,000
GBP
|
— | — | — | — | — |
–
GBP
|
— | — | — | — | — |
| Other comprehensive income, before tax, exchange differences on translation of foreign operations |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
40,000,000
GBP
|
–
GBP
|
–
GBP
|
4 0
GBP
|
–
GBP
|
40,000,000
GBP
|
–
GBP
|
95,000,000
GBP
|
–
GBP
|
— | — |
95,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
95,000,000
GBP
|
| Cash flow hedges [abstract] | ||||||||||||||||||||||
| Reclassification adjustments on cash flow hedges, before tax |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
357,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
357,000,000
GBP
|
357,000,000
GBP
|
–
GBP
|
–
GBP
|
9,000,000
GBP
|
— | — |
9,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
9,000,000
GBP
|
| Other comprehensive income, before tax, cash flow hedges |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
1,069,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
1,069,000,000
GBP
|
1,069,000,000
GBP
|
–
GBP
|
–
GBP
|
103,000,000
GBP
|
— | — |
103,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
103,000,000
GBP
|
| Hedges of net investment in foreign operations [abstract] | ||||||||||||||||||||||
| Other comprehensive income, before tax, hedges of net investments in foreign operations |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
28,000,000
GBP
|
–
GBP
|
–
GBP
|
28,000,000
GBP
|
–
GBP
|
28,000,000
GBP
|
–
GBP
|
2,000,000
GBP
|
–
GBP
|
— | — |
2,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
2,000,000
GBP
|
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||||||||
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss | — | — | — | — | — | — | — | — | — | — |
14,000,000
GBP
|
— | — | — | — | — |
5,000,000
GBP
|
— | — | — | — | — |
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract] | ||||||||||||||||||||||
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss | — | — | — | — | — | — | — | — | — | — |
162,000,000
GBP
|
— | — | — | — | — |
21,000,000
GBP
|
— | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — | — | — |
589,000,000
GBP
|
— | — | — | — | — |
19,000,000
GBP
|
— | — | — | — | — |
| Comprehensive income |
–
GBP
|
— | — |
–
GBP
|
334,000,000
GBP
|
869,000,000
GBP
|
–
GBP
|
–
GBP
|
14,000,000
GBP
|
549,000,000
GBP
|
869,000,000
GBP
|
–
GBP
|
9 8
GBP
|
92,000,000
GBP
|
— | — |
175,000,000
GBP
|
181,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
17 5
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — | — | — | — | — |
869,000,000
GBP
|
— | — | — | — | — |
175,000,000
GBP
|
— | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — | — | — | — | — | — |
–
GBP
|
— | — | — | — | — |
–
GBP
|
— | — | — | — | — |