Statement Of Cash Flows [Abstract]
| Concept |
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 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 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] | |||||||||||||||||
| Profit (loss) | — |
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
308,500,000
GBP
|
308,500,000
GBP
|
226,400,000
GBP
|
—
GBP
|
— |
226,400,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
— |
| Cash flows from (used in) operating activities | — | — | — | — | — | — |
167,700,000
GBP
|
— | — | — | — |
7,400,000
GBP
|
— | — | — | — | — |
| Cash flows from (used in) investing activities [abstract] | |||||||||||||||||
| Purchase of property, plant and equipment, classified as investing activities | — | — | — | — | — | — |
21,400,000
GBP
|
— | — | — | — |
5,800,000
GBP
|
— | — | — | — | — |
| Purchase of intangible assets, classified as investing activities | — | — | — | — | — | — |
34,600,000
GBP
|
— | — | — | — |
20,500,000
GBP
|
— | — | — | — | — |
| Interest received, classified as investing activities | — | — | — | — | — | — |
500,000
GBP
|
— | — | — | — |
900,000
GBP
|
— | — | — | — | — |
| Cash flows from (used in) investing activities | — | — | — | — | — | — |
58,400,000
GBP
|
— | — | — | — |
25,400,000
GBP
|
— | — | — | — | — |
| Cash flows from (used in) financing activities [abstract] | |||||||||||||||||
| Proceeds from issuing shares | — | — | — | — | — | — |
1,150,200,000
GBP
|
— | — | — | — |
178,000,000
GBP
|
— | — | — | — | — |
| Payments of lease liabilities, classified as financing activities | — | — | — | — | — | — |
10,000,000
GBP
|
— | — | — | — |
9,700,000
GBP
|
— | — | — | — | — |
| Interest paid, classified as financing activities | — | — | — | — | — | — |
1,200,000
GBP
|
— | — | — | — |
1,200,000
GBP
|
— | — | — | — | — |
| Cash flows from (used in) financing activities | — | — | — | — | — | — |
1,139,000,000
GBP
|
— | — | — | — |
167,100,000
GBP
|
— | — | — | — | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — | — | — | — | — | — |
912,900,000
GBP
|
— | — | — | — |
149,100,000
GBP
|
— | — | — | — | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||||||||||||||
| Effect of exchange rate changes on cash and cash equivalents | — | — | — | — | — | — |
1,100,000
GBP
|
— | — | — | — |
200,000
GBP
|
— | — | — | — | — |
| Cash and cash equivalents |
1,290,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
379,100,000
GBP
|
— | — | — | — | — |
229,800,000
GBP
|