Statement Of Financial Position [Abstract]
| Concept |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||
| Assets [abstract] | |||||||||||||||
| Non-current assets [abstract] | |||||||||||||||
| Property, plant and equipment |
1,000,000
GBP
|
— | — | — | — | — |
800,000
GBP
|
— | — | — | — | — | — | — | — |
| Right-of-use assets |
7,100,000
GBP
|
— | — | — | — | — |
14,400,000
GBP
|
— | — | — | — | — | — | — | — |
| Goodwill |
24,700,000
GBP
|
— | — | — | — | — |
24,700,000
GBP
|
— | — | — | — | — | — | — | — |
| Intangible assets other than goodwill |
2,900,000
GBP
|
— | — | — | — | — |
2,400,000
GBP
|
— | — | — | — | — | — | — | — |
| Deferred tax assets |
1,600,000
GBP
|
— | — | — | — | — |
1,800,000
GBP
|
— | — | — | — | — | — | — | — |
| Non-current assets |
37,500,000
GBP
|
— | — | — | — | — |
44,400,000
GBP
|
— | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||
| Trade and other current receivables |
8,900,000
GBP
|
— | — | — | — | — |
6,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Cash and cash equivalents |
18,700,000
GBP
|
— | — | — | — | — |
23,100,000
GBP
|
— | — | — |
37,000,000
GBP
|
— | — | — | — |
| Current assets |
39,000,000
GBP
|
— | — | — | — | — |
39,600,000
GBP
|
— | — | — | — | — | — | — | — |
| Assets |
76,500,000
GBP
|
— | — | — | — | — |
84,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||
| Equity [abstract] | |||||||||||||||
| Issued capital |
300,000
GBP
|
— | — | — | — | — |
300,000
GBP
|
— | — | — | — | — | — | — | — |
| Retained earnings |
48,800,000
GBP
|
— | — | — | — | — |
46,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Treasury shares |
7. 5
GBP
|
— | — | — | — | — |
3 .4
GBP
|
— | — | — | — | — | — | — | — |
| Equity |
42,000,000
GBP
|
48,800,000
GBP
|
7. 5
GBP
|
300,000
GBP
|
400,000
GBP
|
3. 4
GBP
|
43,400,000
GBP
|
46,500,000
GBP
|
–
GBP
|
300,000
GBP
|
60,200,000
GBP
|
300,000
GBP
|
59,800,000
GBP
|
–
GBP
|
100,000
GBP
|
| Liabilities [abstract] | |||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||
| Non-current provisions |
900,000
GBP
|
— | — | — | — | — |
1,400,000
GBP
|
— | — | — | — | — | — | — | — |
| Non-current liabilities |
8,900,000
GBP
|
— | — | — | — | — |
16,600,000
GBP
|
— | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||
| Trade and other current payables |
9,500,000
GBP
|
— | — | — | — | — |
9,300,000
GBP
|
— | — | — | — | — | — | — | — |
| Current liabilities |
25,600,000
GBP
|
— | — | — | — | — |
24,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Liabilities |
34,500,000
GBP
|
— | — | — | — | — |
40,600,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity and liabilities |
76,500,000
GBP
|
— | — | — | — | — |
84,000,000
GBP
|
— | — | — | — | — | — | — | — |