Statement Of Cash Flows [Abstract]
| Concept |
2022-01-01 to 2022-12-30 |
As at 2022-12-30 |
As at 2021-12-31 |
2020-12-26 to 2021-12-31 |
|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||
| Cash flows from (used in) operating activities [abstract] | ||||
| Cash flows from (used in) operations |
17,700,000
GBP
|
— | — |
68,300,000
GBP
|
| Interest paid, classified as operating activities |
27,800,000
GBP
|
— | — |
40,200,000
GBP
|
| Income taxes paid (refund), classified as operating activities |
2,300,000
GBP
|
— | — |
17,700,000
GBP
|
| Cash flows from (used in) operating activities |
47,800,000
GBP
|
— | — |
22,400,000
GBP
|
| Cash flows from (used in) investing activities [abstract] | ||||
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities |
200,000
GBP
|
— | — |
200,000
GBP
|
| Proceeds from sales of property, plant and equipment, classified as investing activities |
300,000
GBP
|
— | — |
1,200,000
GBP
|
| Cash flows from (used in) investing activities |
7,400,000
GBP
|
— | — |
5,700,000
GBP
|
| Cash flows from (used in) financing activities [abstract] | ||||
| Payments of lease liabilities, classified as financing activities |
7,200,000
GBP
|
— | — |
9,100,000
GBP
|
| Cash flows from (used in) financing activities |
18,200,000
GBP
|
— | — |
19,300,000
GBP
|
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes |
58,600,000
GBP
|
— | — |
2,600,000
GBP
|
| Cash and cash equivalents | — |
17,100,000
GBP
|
75,700,000
GBP
|
— |