Statement Of Changes In Equity [Abstract]
| Concept |
2021-04-01 to 2022-03-31 |
As at 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 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
2021-04-01 to 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
2021-04-01 to 2022-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
As at 2021-03-31 |
2020-04-01 to 2021-03-31 |
As at 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 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
As at 2020-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||||||||
| Equity | — |
43,000,000
GBP
|
— | — | — | — | — | — |
10 0
GBP
|
1 0 ,1 5 1
GBP
|
7 19
GBP
|
6,000,000
GBP
|
789,000,000
GBP
|
1 ,12 5
GBP
|
— |
12 , 7 5 4
GBP
|
33,000,000
GBP
|
— |
34,000,000
GBP
|
43,000,000
GBP
|
64,000,000
GBP
|
6,733,000,000
GBP
|
9 16
GBP
|
9,16 4
GBP
|
7 19
GBP
|
78 8
GBP
|
— |
5,000,000
GBP
|
— | — | — | — | — | — | — | — |
33,000,000
GBP
|
7, 7 5 7
GBP
|
2,000,000
GBP
|
43,000,000
GBP
|
78,000,000
GBP
|
5,432,000,000
GBP
|
78 8
GBP
|
719,000,000
GBP
|
82 2
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) |
–
GBP
|
— |
–
GBP
|
3 , 5 47
GBP
|
–
GBP
|
–
GBP
|
466,000,000
GBP
|
–
GBP
|
— | — | — | — | — | — |
4 , 0 13
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — |
–
GBP
|
— |
–
GBP
|
–
GBP
|
1, 7 0 7
GBP
|
–
GBP
|
1, 8 5 5
GBP
|
–
GBP
|
–
GBP
|
14 8
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
12 9
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Comprehensive income |
–
GBP
|
— |
–
GBP
|
3,5 49
GBP
|
–
GBP
|
1,000,000
GBP
|
466,000,000
GBP
|
–
GBP
|
— | — | — | — | — | — |
4 , 0 14
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — |
–
GBP
|
— |
3,000,000
GBP
|
–
GBP
|
1, 5 8 1
GBP
|
–
GBP
|
1,7 2 6
GBP
|
–
GBP
|
–
GBP
|
14 8
GBP
|
— | — | — | — | — | — | — | — | — |
| Issue of equity |
–
GBP
|
— |
–
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — |
1,000,000
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — |
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners |
–
GBP
|
— |
–
GBP
|
113,000,000
GBP
|
–
GBP
|
–
GBP
|
2 76
GBP
|
–
GBP
|
— | — | — | — | — | — |
389,000,000
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — |
–
GBP
|
— |
–
GBP
|
–
GBP
|
26 6
GBP
|
–
GBP
|
3 38
GBP
|
–
GBP
|
–
GBP
|
72,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity |
18,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — |
18,000,000
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — |
19,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
19,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |