Statement Of Cash Flows [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
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 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||||||||||||
| Cash flows from (used in) operating activities [abstract] | ||||||||||||||
| Profit (loss) |
—
GBP
|
—
GBP
|
27 .3
GBP
|
— |
—
GBP
|
27 .3
GBP
|
—
GBP
|
— |
—
GBP
|
—
GBP
|
—
GBP
|
56,300,000
GBP
|
—
GBP
|
56,300,000
GBP
|
| Adjustments to reconcile profit (loss) [abstract] | ||||||||||||||
| Adjustments for income tax expense | — | — |
1,200,000
GBP
|
— | — | — | — | — | — | — | — |
600,000
GBP
|
— | — |
| Adjustments for finance costs | — | — |
45,200,000
GBP
|
— | — | — | — | — | — | — | — |
41,200,000
GBP
|
— | — |
| Income taxes paid (refund), classified as operating activities | — | — |
300,000
GBP
|
— | — | — | — | — | — | — | — |
200,000
GBP
|
— | — |
| Cash flows from (used in) operating activities | — | — |
133,600,000
GBP
|
— | — | — | — | — | — | — | — |
117 .6
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | ||||||||||||||
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities | — | — |
5,100,000
GBP
|
— | — | — | — | — | — | — | — |
—
GBP
|
— | — |
| Interest received, classified as investing activities | — | — |
—
GBP
|
— | — | — | — | — | — | — | — |
1,500,000
GBP
|
— | — |
| Cash flows from (used in) investing activities | — | — |
44,600,000
GBP
|
— | — | — | — | — | — | — | — |
45,800,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | ||||||||||||||
| Proceeds from borrowings, classified as financing activities | — | — |
282,400,000
GBP
|
— | — | — | — | — | — | — | — |
161,600,000
GBP
|
— | — |
| Repayments of borrowings, classified as financing activities | — | — |
300,000,000
GBP
|
— | — | — | — | — | — | — | — |
175,700,000
GBP
|
— | — |
| Dividends paid, classified as financing activities | — | — |
89 .5
GBP
|
— | — | — | — | — | — | — | — |
81,600,000
GBP
|
— | — |
| Interest paid, classified as financing activities | — | — |
47 .0
GBP
|
— | — | — | — | — | — | — | — |
39 .8
GBP
|
— | — |
| Cash flows from (used in) financing activities | — | — |
114,900,000
GBP
|
— | — | — | — | — | — | — | — |
76,800,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — | — |
25,900,000
GBP
|
— | — | — | — | — | — | — | — |
5,000,000
GBP
|
— | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | ||||||||||||||
| Effect of exchange rate changes on cash and cash equivalents | — | — |
—
GBP
|
— | — | — | — | — | — | — | — |
700,000
GBP
|
— | — |
| Cash and cash equivalents | — | — | — |
3,200,000
GBP
|
— | — | — |
29 .1
GBP
|
— | — | — | — | — | — |