Statement Of Changes In Equity [Abstract]
| Concept |
As at 2022-12-30 |
As at 2022-12-30 |
As at 2022-12-30 |
As at 2022-12-30 |
As at 2022-12-30 |
As at 2022-12-30 |
2022-01-01 to 2022-12-30 |
2022-01-01 to 2022-12-30 |
2022-01-01 to 2022-12-30 |
2022-01-01 to 2022-12-30 |
2022-01-01 to 2022-12-30 |
2022-01-01 to 2022-12-30 |
2020-12-26 to 2021-12-31 |
2020-12-26 to 2021-12-31 |
2020-12-26 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2020-12-26 to 2021-12-31 |
As at 2021-12-31 |
2020-12-26 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2020-12-26 to 2021-12-31 |
As at 2020-12-25 |
As at 2020-12-25 |
As at 2020-12-25 |
As at 2020-12-25 |
As at 2020-12-25 |
As at 2020-12-25 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||||||||||||||
| Equity |
2,000,000
GBP
|
141,700,000
GBP
|
422,200,000
GBP
|
581,100,000
GBP
|
13,000,000
GBP
|
6,200,000
GBP
|
— | — | — | — | — | — | — | — | — |
6,200,000
GBP
|
141,700,000
GBP
|
— |
309,600,000
GBP
|
— |
2,300,000
GBP
|
151,100,000
GBP
|
12,900,000
GBP
|
— |
335,100,000
GBP
|
3,000,000
GBP
|
177,500,000
GBP
|
6,200,000
GBP
|
141,700,000
GBP
|
12,700,000
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) | — | — | — | — | — | — |
275,200,000
GBP
|
–
GBP
|
–
GBP
|
275,200,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
12,100,000
GBP
|
— | — |
–
GBP
|
— |
–
GBP
|
— | — | — |
12,100,000
GBP
|
— | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — |
3,700,000
GBP
|
–
GBP
|
–
GBP
|
3,700,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
13,400,000
GBP
|
— | — |
–
GBP
|
— |
–
GBP
|
— | — | — |
13,400,000
GBP
|
— | — | — | — | — | — |
| Comprehensive income | — | — | — | — | — | — |
271,500,000
GBP
|
–
GBP
|
–
GBP
|
271,500,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
25,500,000
GBP
|
— | — |
–
GBP
|
— |
–
GBP
|
— | — | — |
25,500,000
GBP
|
— | — | — | — | — | — |