Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-12-31 |
As at 2022-01-02 |
As at 2022-01-01 |
As at 2021-01-03 |
|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||||
| Property, plant and equipment [abstract] | ||||
| Property, plant and equipment |
3 90.0
GBP
|
— |
34 3.8
GBP
|
— |
| Intangible assets and goodwill [abstract] | ||||
| Intangible assets and goodwill |
13,500,000
GBP
|
— |
14,900,000
GBP
|
— |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements [abstract] | ||||
| Investments in subsidiaries reported in separate financial statements |
–
GBP
|
— |
–
GBP
|
— |
| Miscellaneous non-current assets [abstract] | ||||
| Non-current net defined benefit asset |
6,300,000
GBP
|
— |
–
GBP
|
— |
| Trade and other current receivables [abstract] | ||||
| Trade and other current receivables |
50,200,000
GBP
|
— |
3 7. 6
GBP
|
— |
| Classes of current inventories [abstract] | ||||
| Current inventories |
4 0.6
GBP
|
— |
2 7. 9
GBP
|
— |
| Classes of current inventories, alternative [abstract] | ||||
| Cash and cash equivalents [abstract] | ||||
| Cash and cash equivalents |
1 9 1.6
GBP
|
1 98 .6
GBP
|
19 8.6
GBP
|
3 6.8
GBP
|
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | ||||
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners |
–
GBP
|
— |
1. 6
GBP
|
— |
| Trade and other non-current payables [abstract] | ||||
| Other non-current payables |
2 . 8
GBP
|
— |
3 .2
GBP
|
— |
| Trade and other current payables [abstract] | ||||
| Trade and other current payables |
1 9 1 .7
GBP
|
— |
1 5 3. 4
GBP
|
— |
| Miscellaneous non-current liabilities [abstract] | ||||
| Non-current net defined benefit liability |
–
GBP
|
— |
2 .4
GBP
|
— |
| Issued capital [abstract] | ||||
| Issued capital |
2,000,000
GBP
|
— |
2 .0
GBP
|
— |
| Retained earnings [abstract] | ||||
| Retained earnings |
420,500,000
GBP
|
— |
4 06 .8
GBP
|
— |
| Miscellaneous equity [abstract] | ||||
| Capital redemption reserve |
400,000
GBP
|
— |
0 .4
GBP
|
— |
| Net assets (liabilities) [abstract] | ||||
| Assets |
9 74.4
GBP
|
— |
888. 4
GBP
|
— |
| Liabilities |
5 2 8 . 4
GBP
|
— |
459,200,000
GBP
|
— |
| Assets (liabilities) |
44 6.0
GBP
|
— |
429. 2
GBP
|
— |
| Net current assets (liabilities) [abstract] | ||||
| Current assets |
28 3.0
GBP
|
— |
2 6 6 .1
GBP
|
— |
| Current liabilities |
2 4 4.1
GBP
|
— |
2 0 6 . 9
GBP
|
— |
| Assets less current liabilities [abstract] |