Statement Of Financial Position [Abstract]
| Concept |
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 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 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 |
As at 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 financial position [abstract] | |||||||||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||||||||
| Non-current assets [abstract] | |||||||||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — | — | — |
3,000,000
GBP
|
— | — | — | — | — | — |
5,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Right-of-use assets | — | — | — | — | — | — | — |
13,000,000
GBP
|
— | — | — | — | — | — |
16,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — | — | — | — | — |
13 , 5 7 0
GBP
|
— | — | — | — | — | — |
10 , 07 7
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||||||||
| Cash and cash equivalents | — | — | — | — | — | — | — |
2 12
GBP
|
— | — | — | — | — | — |
2 16
GBP
|
— | — | — | — | — |
7 71
GBP
|
— | — | — | — | — | — |
| Current assets | — | — | — | — | — | — | — |
378,000,000
GBP
|
— | — | — | — | — | — |
257,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Assets | — | — | — | — | — | — | — |
13 ,9 4 8
GBP
|
— | — | — | — | — | — |
10, 3 3 4
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||||||||
| Issued capital | — | — | — | — | — | — | — |
7 19
GBP
|
— | — | — | — | — | — |
719,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — | — | — | — | — |
1,1 2 5
GBP
|
— | — | — | — | — | — |
9 16
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Share premium | — | — | — | — | — | — | — |
789,000,000
GBP
|
— | — | — | — | — | — |
78 8
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Treasury shares | — | — | — | — | — | — | — |
10 0
GBP
|
— | — | — | — | — | — |
6 4
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| 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
|
2,000,000
GBP
|
7, 7 5 7
GBP
|
43,000,000
GBP
|
78,000,000
GBP
|
5,432,000,000
GBP
|
78 8
GBP
|
719,000,000
GBP
|
82 2
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||||||||
| Non-current provisions | — | — | — | — | — | — | — |
3,000,000
GBP
|
— | — | — | — | — | — |
2,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other non-current payables | — | — | — | — | — | — | — |
14,000,000
GBP
|
— | — | — | — | — | — |
17,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — | — | — | — | — |
870,000,000
GBP
|
— | — | — | — | — | — |
1, 0 8 6
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||||||||
| Trade and other current payables | — | — | — | — | — | — | — |
80,000,000
GBP
|
— | — | — | — | — | — |
6 2
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — | — | — | — | — |
324,000,000
GBP
|
— | — | — | — | — | — |
8 4
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — | — | — | — | — |
1 ,1 9 4
GBP
|
— | — | — | — | — | — |
1,1 7 0
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |