Statement Of Cash Flows [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||
| Cash flows from (used in) operating activities [abstract] | |||||
| Cash flows from (used in) operations |
126,700,000
GBP
|
— | — |
60,200,000
GBP
|
— |
| Income taxes paid (refund), classified as operating activities |
30,300,000
GBP
|
— | — |
31,800,000
GBP
|
— |
| Cash flows from (used in) operating activities |
78,500,000
GBP
|
— | — |
19,000,000
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | |||||
| Proceeds from sales of property, plant and equipment, classified as investing activities |
1,800,000
GBP
|
— | — |
600,000
GBP
|
— |
| Purchase of property, plant and equipment, classified as investing activities |
60,400,000
GBP
|
— | — |
58,000,000
GBP
|
— |
| Interest received, classified as investing activities |
3,900,000
GBP
|
— | — |
1,600,000
GBP
|
— |
| Cash flows from (used in) investing activities |
60,200,000
GBP
|
— | — |
55,400,000
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | |||||
| Proceeds from borrowings, classified as financing activities |
247,200,000
GBP
|
— | — |
113,300,000
GBP
|
— |
| Repayments of borrowings, classified as financing activities |
193,900,000
GBP
|
— | — |
39,000,000
GBP
|
— |
| Payments of lease liabilities, classified as financing activities |
8,900,000
GBP
|
— | — |
9,000,000
GBP
|
— |
| Cash flows from (used in) financing activities |
2,000,000
GBP
|
— | — |
23,400,000
GBP
|
— |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||
| Effect of exchange rate changes on cash and cash equivalents |
9,500,000
GBP
|
— | — |
3,400,000
GBP
|
— |
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes |
16,300,000
GBP
|
— | — |
13,000,000
GBP
|
— |
| Cash and cash equivalents | — |
124,500,000
GBP
|
117,700,000
GBP
|
— |
127,300,000
GBP
|