Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
25,882,000
GBP
|
26,387,000
GBP
|
18,613,000
GBP
|
| Intangible assets and goodwill [abstract] | |||
| Intangible assets other than goodwill [abstract] | |||
| Intangible assets other than goodwill |
19,054,000
GBP
|
13,278,000
GBP
|
8,478,000
GBP
|
| Investments accounted for using equity method [abstract] | |||
| Investments in associates accounted for using equity method |
2,350,000
GBP
|
2,460,000
GBP
|
500,000
GBP
|
| Trade and other non-current receivables [abstract] | |||
| Other non-current receivables |
741,000
GBP
|
741,000
GBP
|
741,000
GBP
|
| Miscellaneous non-current assets [abstract] | |||
| Non-current investments other than investments accounted for using equity method |
—
GBP
|
—
GBP
|
5,000,000
GBP
|
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables |
9,876,000
GBP
|
17,153,000
GBP
|
5,813,000
GBP
|
| Current prepayments and current accrued income including current contract assets [abstract] | |||
| Current accrued income including current contract assets [abstract] | |||
| Current contract assets |
1,575,000
GBP
|
400,000
GBP
|
5,343,000
GBP
|
| Classes of current inventories [abstract] | |||
| Current inventories |
2,825,000
GBP
|
5,714,000
GBP
|
3,145,000
GBP
|
| Classes of current inventories, alternative [abstract] | |||
| Cash and cash equivalents [abstract] | |||
| Cash equivalents [abstract] | |||
| Short-term investments, classified as cash equivalents |
90,249,000
GBP
|
110,536,000
GBP
|
93,129,000
GBP
|
| Cash and cash equivalents |
49,707,000
GBP
|
71,784,000
GBP
|
151,455,000
GBP
|
| Miscellaneous current assets [abstract] | |||
| Current derivative financial assets |
8,000
GBP
|
54,000
GBP
|
1,073,000
GBP
|
| Other current assets |
1,193,000
GBP
|
957,000
GBP
|
1,133,000
GBP
|
| Trade and other current payables [abstract] | |||
| Current accruals and current deferred income including current contract liabilities [abstract] | |||
| Current deferred income including current contract liabilities [abstract] | |||
| Current contract liabilities [abstract] | |||
| Current contract liabilities |
7,469,000
GBP
|
7,363,000
GBP
|
3,917,000
GBP
|
| Trade and other current payables |
4,983,000
GBP
|
4,933,000
GBP
|
2,783,000
GBP
|
| Miscellaneous non-current liabilities [abstract] | |||
| Other non-current liabilities |
1,360,000
GBP
|
1,011,000
GBP
|
771,000
GBP
|
| Miscellaneous current liabilities [abstract] | |||
| Current derivative financial liabilities |
99,000
GBP
|
—
GBP
|
—
GBP
|
| Other current liabilities |
6,301,000
GBP
|
6,275,000
GBP
|
5,047,000
GBP
|
| Issued capital [abstract] | |||
| Issued capital |
19,297,000
GBP
|
19,209,000
GBP
|
19,073,000
GBP
|
| Retained earnings [abstract] | |||
| Retained earnings |
255,758,000
GBP
|
201,817,000
GBP
|
155,199,000
GBP
|
| Miscellaneous equity [abstract] | |||
| Capital redemption reserve |
3,449,000
GBP
|
3,449,000
GBP
|
3,449,000
GBP
|
| Merger reserve |
7,463,000
GBP
|
7,463,000
GBP
|
7,463,000
GBP
|
| Net assets (liabilities) [abstract] | |||
| Assets (liabilities) |
180,635,000
GBP
|
233,767,000
GBP
|
279,512,000
GBP
|
| Net current assets (liabilities) [abstract] | |||
| Current assets |
156,204,000
GBP
|
213,994,000
GBP
|
262,706,000
GBP
|
| Current liabilities |
20,193,000
GBP
|
20,110,000
GBP
|
14,080,000
GBP
|
| Current assets (liabilities) |
136,011,000
GBP
|
193,884,000
GBP
|
248,626,000
GBP
|
| Assets less current liabilities [abstract] |