Statement Of Cash Flows [Abstract]
| Concept |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||
| Cash flows from (used in) operating activities [abstract] | |||||
| Cash flows from (used in) operations | — |
34,000,000
GBP
|
— |
31,300,000
GBP
|
— |
| Interest paid, classified as operating activities | — |
600,000
GBP
|
— |
0. 8
GBP
|
— |
| Income taxes paid (refund), classified as operating activities | — |
6 . 2
GBP
|
— |
3,800,000
GBP
|
— |
| Cash flows from (used in) operating activities | — |
27,200,000
GBP
|
— |
26,700,000
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | |||||
| Purchase of property, plant and equipment, classified as investing activities | — |
0 .7
GBP
|
— |
0. 3
GBP
|
— |
| Cash flows from (used in) investing activities | — |
2 .3
GBP
|
— |
1. 3
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | |||||
| Payments to acquire or redeem entity's shares | — |
5 .6
GBP
|
— |
4. 6
GBP
|
— |
| Payments of lease liabilities, classified as financing activities | — |
1. 6
GBP
|
— |
1 .9
GBP
|
— |
| Dividends paid, classified as financing activities | — |
22,500,000
GBP
|
— |
32 .7
GBP
|
— |
| Cash flows from (used in) financing activities | — |
2 9 .7
GBP
|
— |
3 9. 2
GBP
|
— |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — |
4 . 8
GBP
|
— |
13 . 8
GBP
|
— |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||
| Effect of exchange rate changes on cash and cash equivalents | — |
400,000
GBP
|
— |
0 .1
GBP
|
— |
| Cash and cash equivalents |
18,700,000
GBP
|
— |
23,100,000
GBP
|
— |
37,000,000
GBP
|