Analysis Of Income And Expense [Abstract]
| Concept |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2021-04-01 to 2022-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
2020-04-01 to 2021-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Analysis of income and expense [abstract] | ||||||||||||||||||||||
| Revenue [abstract] | ||||||||||||||||||||||
| Revenue | — | — | — | — | — | — | — |
410,000,000
GBP
|
430,000,000
GBP
|
20,000,000
GBP
|
— | — | — |
468,000,000
GBP
|
–
GBP
|
468,000,000
GBP
|
— | — | — | — | — | — |
| Material income and expense [abstract] | ||||||||||||||||||||||
| Finance income (cost) | — | — | — | — | — | — | — |
5,000,000
GBP
|
55,000,000
GBP
|
60,000,000
GBP
|
— | — | — |
62,000,000
GBP
|
12,000,000
GBP
|
50,000,000
GBP
|
— | — | — | — | — | — |
| Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract] | ||||||||||||||||||||||
| Share of profit (loss) of joint ventures accounted for using equity method | — | — | — | — | — | — | — |
244,000,000
GBP
|
86,000,000
GBP
|
158,000,000
GBP
|
— | — | — |
52,000,000
GBP
|
409,000,000
GBP
|
357,000,000
GBP
|
— | — | — | — | — | — |
| Income tax relating to components of other comprehensive income [abstract] | ||||||||||||||||||||||
| Income tax relating to components of other comprehensive income | — | — | — | — | — | — | — |
–
GBP
|
— | — | — |
–
GBP
|
6,000,000
GBP
|
— | — |
6,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
6,000,000
GBP
|
| Comprehensive income, continuing and discontinued operations [abstract] | ||||||||||||||||||||||
| Comprehensive income |
947,000,000
GBP
|
–
GBP
|
2,000,000
GBP
|
958,000,000
GBP
|
–
GBP
|
–
GBP
|
12,000,000
GBP
|
949,000,000
GBP
|
— | — |
1,000,000
GBP
|
–
GBP
|
24,000,000
GBP
|
— | — |
1,088,000,000
GBP
|
–
GBP
|
–
GBP
|
1,014,000,000
GBP
|
2,000,000
GBP
|
52,000,000
GBP
|
1,036,000,000
GBP
|
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — | — |
947,000,000
GBP
|
— | — | — | — | — | — | — |
1,036,000,000
GBP
|
— | — | — | — | — | — |
| Comprehensive income attributable to non-controlling interests, continuing and discontinued operations [abstract] | ||||||||||||||||||||||
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — | — | — |
2,000,000
GBP
|
— | — | — | — | — | — | — |
52,000,000
GBP
|
— | — | — | — | — | — |