Statement Of Comprehensive Income [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||||||||
| Profit (loss) |
226,800,000
GBP
|
–
GBP
|
1,300,000
GBP
|
228,100,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
158,800,000
GBP
|
68,000,000
GBP
|
–
GBP
|
527,700,000
GBP
|
528,600,000
GBP
|
900,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
44,000,000
GBP
|
483,700,000
GBP
|
–
GBP
|
–
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 |
100,000
GBP
|
–
GBP
|
–
GBP
|
100,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
6,800,000
GBP
|
6,800,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
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 |
4,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
4,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
3,800,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
3,800,000
GBP
|
| Cash flow hedges [abstract] | ||||||||||||||||||||||||
| Gains (losses) on cash flow hedges, before tax |
700,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
700,000
GBP
|
— | — |
–
GBP
|
6,100,000
GBP
|
–
GBP
|
–
GBP
|
6,100,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
| Reclassification adjustments on cash flow hedges, before tax |
5,400,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
5,400,000
GBP
|
— | — |
–
GBP
|
2,900,000
GBP
|
–
GBP
|
–
GBP
|
2,900,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
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 |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
1,700,000
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 |
1,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
800,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Other comprehensive income |
7,600,000
GBP
|
–
GBP
|
–
GBP
|
0 .1
GBP
|
–
GBP
|
4,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
3,500,000
GBP
|
— | — |
–
GBP
|
6,500,000
GBP
|
5,100,000
GBP
|
–
GBP
|
2,400,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
3,800,000
GBP
|
| Comprehensive income |
234,400,000
GBP
|
–
GBP
|
1,300,000
GBP
|
228,200,000
GBP
|
–
GBP
|
4,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
3,500,000
GBP
|
— | — |
–
GBP
|
521,200,000
GBP
|
523,500,000
GBP
|
900,000
GBP
|
2,400,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — |
–
GBP
|
3,800,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||||||||
| Comprehensive income, attributable to owners of parent |
235,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
522,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests |
1,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
900,000
GBP
|
— | — | — | — | — | — | — | — | — | — |