Statement Of Comprehensive Income [Abstract]
| Concept |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
2022-04-01 to 2023-03-31 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||
| Profit (loss) |
276,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
276,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
101,000,000
GBP
|
–
GBP
|
–
GBP
|
101,000,000
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 |
12,000,000
GBP
|
12,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
5,000,000
GBP
|
–
GBP
|
5,000,000
GBP
|
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans |
149,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
149,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
177,000,000
GBP
|
–
GBP
|
–
GBP
|
177,000,000
GBP
|
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||
| Hedges of net investment in foreign operations [abstract] | ||||||||||||
| Other comprehensive income, before tax, hedges of net investments in foreign operations |
10,000,000
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 |
37,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
35,000,000
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 |
28,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
10,000,000
GBP
|
| Other comprehensive income |
47,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
189,000,000
GBP
|
| Comprehensive income |
229,000,000
GBP
|
65,000,000
GBP
|
–
GBP
|
–
GBP
|
164,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
41,000,000
GBP
|
47,000,000
GBP
|
–
GBP
|
88,000,000
GBP
|