Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2019-12-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
113,300,000
GBP
|
122,900,000
GBP
|
— |
| Intangible assets and goodwill [abstract] | |||
| Intangible assets and goodwill |
18,100,000
GBP
|
21,100,000
GBP
|
— |
| Investment property [abstract] | |||
| Investment property |
–
GBP
|
–
GBP
|
— |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements [abstract] | |||
| Investments in subsidiaries reported in separate financial statements |
–
GBP
|
–
GBP
|
— |
| Trade and other non-current receivables [abstract] | |||
| Trade and other non-current receivables |
–
GBP
|
–
GBP
|
— |
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
114,000,000
GBP
|
101,600,000
GBP
|
— |
| Classes of current inventories [abstract] | |||
| Current inventories |
130,900,000
GBP
|
118,500,000
GBP
|
— |
| Classes of current inventories, alternative [abstract] | |||
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
61,200,000
GBP
|
60,800,000
GBP
|
33,400,000
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 |
–
GBP
|
400,000
GBP
|
— |
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings |
6,900,000
GBP
|
7,200,000
GBP
|
— |
| Current borrowings and current portion of non-current borrowings [abstract] | |||
| Current borrowings |
600,000
GBP
|
2,000,000
GBP
|
— |
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Trade and other current payables [abstract] | |||
| Trade and other current payables |
178,000,000
GBP
|
178,400,000
GBP
|
— |
| Miscellaneous non-current liabilities [abstract] | |||
| Non-current net defined benefit liability |
3,900,000
GBP
|
5,500,000
GBP
|
— |
| Miscellaneous current liabilities [abstract] | |||
| Current net defined benefit liability |
1,000,000
GBP
|
–
GBP
|
— |
| Issued capital [abstract] | |||
| Issued capital |
4,300,000
GBP
|
4,300,000
GBP
|
— |
| Retained earnings [abstract] | |||
| Retained earnings |
175,900,000
GBP
|
158,800,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||
| Assets |
472,500,000
GBP
|
467,400,000
GBP
|
— |
| Liabilities |
240,400,000
GBP
|
247,400,000
GBP
|
— |
| Assets (liabilities) |
232,100,000
GBP
|
220,000,000
GBP
|
— |
| Net current assets (liabilities) [abstract] | |||
| Current assets |
306,100,000
GBP
|
281,300,000
GBP
|
— |
| Current liabilities |
191,100,000
GBP
|
193,100,000
GBP
|
— |
| Assets less current liabilities [abstract] |