Statement Of Comprehensive Income [Abstract]
| Concept |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
2023-04-01 to 2024-03-31 |
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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||||
| Profit (loss) |
–
GBP
|
–
GBP
|
165,700,000
GBP
|
168,200,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
165,700,000
GBP
|
2,500,000
GBP
|
–
GBP
|
–
GBP
|
35,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
35,000,000
GBP
|
–
GBP
|
1,700,000
GBP
|
33,300,000
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 | — | — | — |
155,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
402,400,000
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 | — | — | — |
300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
4,700,000
GBP
|
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||||||
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — |
38,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
100,800,000
GBP
|
| Income tax relating to share of other comprehensive income of associates and joint ventures accounted for using equity method that will be reclassified to profit or loss | — | — | — |
100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,200,000
GBP
|
| Other comprehensive income |
2,300,000
GBP
|
–
GBP
|
126,600,000
GBP
|
127,800,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
116,700,000
GBP
|
1,200,000
GBP
|
12,200,000
GBP
|
–
GBP
|
302,300,000
GBP
|
–
GBP
|
1,000,000
GBP
|
300,000
GBP
|
–
GBP
|
301,600,000
GBP
|
–
GBP
|
2,000,000
GBP
|
304,300,000
GBP
|
| Comprehensive income |
2,300,000
GBP
|
–
GBP
|
39,100,000
GBP
|
40,400,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
49,000,000
GBP
|
1,300,000
GBP
|
12,200,000
GBP
|
–
GBP
|
337,300,000
GBP
|
–
GBP
|
1,000,000
GBP
|
300,000
GBP
|
–
GBP
|
336,600,000
GBP
|
–
GBP
|
300,000
GBP
|
337,600,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — |
39,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
337,300,000
GBP
|
| Comprehensive income, attributable to non-controlling interests | — | — | — |
1,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
300,000
GBP
|