Statement Of Changes In Equity [Abstract]
| Concept |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2020-12-28 to 2021-12-26 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
2019-12-30 to 2020-12-27 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||||
| Increase (decrease) through change in equity of subsidiaries, equity | — | — | — | — | — | — | — | — | — | — |
4 .6
GBP
|
2,400,000
GBP
|
2,200,000
GBP
|
2. 2
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
| Increase (decrease) through disposal of subsidiary, equity | — | — | — | — | — | — | — | — | — | — |
2 .3
GBP
|
3,100,000
GBP
|
10. 5
GBP
|
800,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
11,300,000
GBP
|
–
GBP
|
| Decrease (increase) through tax on share-based payment transactions, equity |
–
GBP
|
–
GBP
|
500,000
GBP
|
–
GBP
|
500,000
GBP
|
500,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
0 .1
GBP
|
–
GBP
|
–
GBP
|
0 .1
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
0 .1
GBP
|
–
GBP
|
| Purchase of treasury shares |
–
GBP
|
–
GBP
|
8 3 . 4
GBP
|
2 . 9
GBP
|
83 . 4
GBP
|
8 0 .4
GBP
|
–
GBP
|
0 .1
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — | — |