Analysis Of Income And Expense [Abstract]
| Concept |
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 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|
| Analysis of income and expense [abstract] | ||||||||||
| Revenue [abstract] | ||||||||||
| Revenue | — | — | — |
3,212,800,000
GBP
|
— | — | — |
3,034,000,000
GBP
|
— | — |
| Material income and expense [abstract] | ||||||||||
| Miscellaneous other operating income | — | — | — |
1,400,000
GBP
|
— | — | — |
2,700,000
GBP
|
— | — |
| Expenses by nature [abstract] | ||||||||||
| Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss [abstract] | ||||||||||
| Depreciation and amortisation expense [abstract] | ||||||||||
| Amortisation expense | — | — | — |
1,500,000
GBP
|
— | — | — |
3,100,000
GBP
|
— | — |
| Disclosure of attribution of expenses by nature to their function [text block] | — | — | — | — | — | — | — | — | — | — |
| Disclosure of attribution of expenses by nature to their function [abstract] | ||||||||||
| Disclosure of attribution of expenses by nature to their function [line items] | ||||||||||
| Miscellaneous other comprehensive income [abstract] | ||||||||||
| Other comprehensive income, net of tax, exchange differences on translation of foreign operations and hedges of net investments in foreign operations [abstract] | ||||||||||
| Other comprehensive income, net of tax, exchange differences on translation of foreign operations | — | — | — |
–
GBP
|
— | — | — |
200,000
GBP
|
— | — |
| Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract] | ||||||||||
| Share of profit (loss) of associates and joint ventures accounted for using equity method | — | — | — |
5,400,000
GBP
|
— | — | — |
2,300,000
GBP
|
— | — |
| Comprehensive income, continuing and discontinued operations [abstract] | ||||||||||
| Comprehensive income |
–
GBP
|
200,000
GBP
|
–
GBP
|
97,700,000
GBP
|
97,900,000
GBP
|
45,400,000
GBP
|
–
GBP
|
45,400,000
GBP
|
–
GBP
|
–
GBP
|
| Comprehensive income attributable to owners of parent, continuing and discontinued operations [abstract] | ||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — |
97,700,000
GBP
|
— | — | — |
45,400,000
GBP
|
— | — |