Statement Of Cash Flows [Abstract]
| Concept |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||
| Cash flows from (used in) operating activities [abstract] | |||||
| Cash flows from (used in) operations | — |
237,500,000
GBP
|
— |
131,800,000
GBP
|
— |
| Income taxes paid (refund), classified as operating activities | — |
48,600,000
GBP
|
— |
27,200,000
GBP
|
— |
| Cash flows from (used in) operating activities | — |
188,900,000
GBP
|
— |
104,600,000
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | |||||
| Purchase of property, plant and equipment, classified as investing activities | — |
1,400,000
GBP
|
— |
1,300,000
GBP
|
— |
| Purchase of intangible assets, classified as investing activities | — |
2,100,000
GBP
|
— |
1,300,000
GBP
|
— |
| Dividends received, classified as investing activities | — |
1,100,000
GBP
|
— |
800,000
GBP
|
— |
| Cash flows from (used in) investing activities | — |
12,000,000
GBP
|
— |
63,900,000
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | |||||
| Payments to acquire or redeem entity's shares | — |
48,500,000
GBP
|
— |
10,700,000
GBP
|
— |
| Proceeds from borrowings, classified as financing activities | — |
–
GBP
|
— |
49,000,000
GBP
|
— |
| Repayments of borrowings, classified as financing activities | — |
–
GBP
|
— |
111,000,000
GBP
|
— |
| Payments of lease liabilities, classified as financing activities | — |
5,200,000
GBP
|
— |
6,700,000
GBP
|
— |
| Dividends paid, classified as financing activities | — |
109,800,000
GBP
|
— |
83,900,000
GBP
|
— |
| Cash flows from (used in) financing activities | — |
167,700,000
GBP
|
— |
159,800,000
GBP
|
— |
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes | — |
9,200,000
GBP
|
— |
8,700,000
GBP
|
— |
| Cash and cash equivalents |
197,300,000
GBP
|
— |
188,100,000
GBP
|
— |
179,400,000
GBP
|