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 |
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 |
2021-04-01 to 2022-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||
| Profit (loss) |
284,800,000
GBP
|
284,800,000
GBP
|
–
GBP
|
–
GBP
|
284,800,000
GBP
|
–
GBP
|
–
GBP
|
230,000,000
GBP
|
–
GBP
|
–
GBP
|
230,000,000
GBP
|
–
GBP
|
–
GBP
|
230,000,000
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) on remeasurements of defined benefit plans |
34,200,000
GBP
|
34,200,000
GBP
|
–
GBP
|
–
GBP
|
34,200,000
GBP
|
–
GBP
|
–
GBP
|
21,800,000
GBP
|
–
GBP
|
–
GBP
|
21,800,000
GBP
|
–
GBP
|
–
GBP
|
21,800,000
GBP
|
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||
| Exchange differences on translation [abstract] | ||||||||||||||
| Other comprehensive income, before tax, exchange differences on translation of foreign operations |
43,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
21,900,000
GBP
|
| Cash flow hedges [abstract] | ||||||||||||||
| Gains (losses) on cash flow hedges, before tax |
3,900,000
GBP
|
3,900,000
GBP
|
3,900,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
1,400,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
1,400,000
GBP
|
1,400,000
GBP
|
| Other comprehensive income, before tax, cash flow hedges |
3,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
1,400,000
GBP
|
| Hedges of net investment in foreign operations [abstract] | ||||||||||||||
| Gains (losses) on hedges of net investments in foreign operations, before tax |
5,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
100,000
GBP
|
| Share of other comprehensive income of associates and joint ventures accounted for using equity method that will be reclassified to profit or loss, before tax |
100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
100,000
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 |
7,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
900,000
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 |
700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
300,000
GBP
|
| Other comprehensive income |
25,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
43,900,000
GBP
|
| Comprehensive income |
310,100,000
GBP
|
310,100,000
GBP
|
51,600,000
GBP
|
–
GBP
|
258,500,000
GBP
|
–
GBP
|
–
GBP
|
273,900,000
GBP
|
–
GBP
|
–
GBP
|
250,900,000
GBP
|
–
GBP
|
23,000,000
GBP
|
273,900,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||
| Comprehensive income, attributable to owners of parent |
310,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
273,900,000
GBP
|