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 |
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) |
526,200,000
GBP
|
— |
526,200,000
GBP
|
— | — |
474,400,000
GBP
|
474,400,000
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 |
2,900,000
GBP
|
— |
2,900,000
GBP
|
— | — |
6,900,000
GBP
|
6,900,000
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 |
126,900,000
GBP
|
— | — |
126,900,000
GBP
|
— |
232,900,000
GBP
|
— |
232,900,000
GBP
|
| Hedges of net investment in foreign operations [abstract] | ||||||||
| Other comprehensive income, before tax, hedges of net investments in foreign operations |
31,400,000
GBP
|
— | — |
31,400,000
GBP
|
— |
38,200,000
GBP
|
— |
38,200,000
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 |
500,000
GBP
|
— | — | — | — |
4,000,000
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 |
500,000
GBP
|
— | — | — | — |
300,000
GBP
|
— | — |
| Other comprehensive income |
94,900,000
GBP
|
— | — | — | — |
208,200,000
GBP
|
— | — |
| Comprehensive income |
431,300,000
GBP
|
1,700,000
GBP
|
529,000,000
GBP
|
96,000,000
GBP
|
7,700,000
GBP
|
682,600,000
GBP
|
479,900,000
GBP
|
195,000,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||
| Comprehensive income, attributable to owners of parent |
431,300,000
GBP
|
— | — | — | — |
682,600,000
GBP
|
— | — |