Statement Of Cash Flows [Abstract]
| Concept |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 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] | |||||||||
| Profit (loss) | — |
81,900,000
GBP
|
–
GBP
|
81,900,000
GBP
|
— |
42,200,000
GBP
|
119,500,000
GBP
|
77,300,000
GBP
|
— |
| Cash flows from (used in) operations | — |
70,500,000
GBP
|
— | — | — | — |
73,100,000
GBP
|
— | — |
| Interest paid, classified as operating activities | — |
24,200,000
GBP
|
— | — | — | — |
24,300,000
GBP
|
— | — |
| Interest received, classified as operating activities | — |
1,300,000
GBP
|
— | — | — | — |
500,000
GBP
|
— | — |
| Cash flows from (used in) operating activities | — |
43,000,000
GBP
|
— | — | — | — |
44,200,000
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | |||||||||
| Cash flows from losing control of subsidiaries or other businesses, classified as investing activities | — |
–
GBP
|
— | — | — | — |
500,000
GBP
|
— | — |
| Purchase of property, plant and equipment, classified as investing activities | — |
400,000
GBP
|
— | — | — | — |
600,000
GBP
|
— | — |
| Purchase of intangible assets, classified as investing activities | — |
800,000
GBP
|
— | — | — | — |
900,000
GBP
|
— | — |
| Cash receipts from repayment of advances and loans made to other parties, classified as investing activities | — |
7,700,000
GBP
|
— | — | — | — |
–
GBP
|
— | — |
| Dividends received, classified as investing activities | — |
–
GBP
|
— | — | — | — |
200,000
GBP
|
— | — |
| Cash flows from (used in) investing activities | — |
81,300,000
GBP
|
— | — | — | — |
165,500,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | |||||||||
| Payments to acquire or redeem entity's shares | — |
25,800,000
GBP
|
— | — | — | — |
–
GBP
|
— | — |
| Proceeds from borrowings, classified as financing activities | — |
144,100,000
GBP
|
— | — | — | — |
196,700,000
GBP
|
— | — |
| Repayments of borrowings, classified as financing activities | — |
99,400,000
GBP
|
— | — | — | — |
107,200,000
GBP
|
— | — |
| Dividends paid, classified as financing activities | — |
32,400,000
GBP
|
— | — | — | — |
30,800,000
GBP
|
— | — |
| Cash flows from (used in) financing activities | — |
14,600,000
GBP
|
— | — | — | — |
57,300,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — |
52,900,000
GBP
|
— | — | — | — |
64,000,000
GBP
|
— | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||||||
| Effect of exchange rate changes on cash and cash equivalents | — |
600,000
GBP
|
— | — | — | — |
4,300,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes | — |
53,500,000
GBP
|
— | — | — | — |
68,300,000
GBP
|
— | — |
| Cash and cash equivalents |
113,900,000
GBP
|
— | — | — |
167,400,000
GBP
|
— | — | — |
235,700,000
GBP
|