Statement Of Comprehensive Income [Abstract]
| Concept |
2022-01-02 to 2022-12-31 |
2022-01-02 to 2022-12-31 |
2022-01-02 to 2022-12-31 |
2022-01-02 to 2022-12-31 |
2022-01-02 to 2022-12-31 |
2021-01-03 to 2022-01-01 |
2021-01-03 to 2022-01-01 |
2021-01-03 to 2022-01-01 |
2021-01-03 to 2022-01-01 |
2021-01-03 to 2022-01-01 |
|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||
| Profit (loss) |
–
GBP
|
120,300,000
GBP
|
–
GBP
|
–
GBP
|
120,300,000
GBP
|
1 1 7. 5
GBP
|
1 1 7. 5
GBP
|
–
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 | — |
700,000
GBP
|
— | — | — |
7,100,000
GBP
|
— | — | — | — |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — |
1,800,000
GBP
|
— | — | — |
1 .7
GBP
|
— | — | — | — |
| Other comprehensive income |
–
GBP
|
2,500,000
GBP
|
–
GBP
|
–
GBP
|
2 .5
GBP
|
5 .4
GBP
|
5 .4
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
| Comprehensive income |
–
GBP
|
122 .8
GBP
|
–
GBP
|
–
GBP
|
122 .8
GBP
|
1 22 .9
GBP
|
12 2.9
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|