Statement Of Comprehensive Income [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 |
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 |
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 |
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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||||||||||||
| Profit (loss) |
1,500,000
GBP
|
–
GBP
|
252,300,000
GBP
|
–
GBP
|
11,600,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
11,600,000
GBP
|
11,600,000
GBP
|
–
GBP
|
253,800,000
GBP
|
252,300,000
GBP
|
81,400,000
GBP
|
1,800,000
GBP
|
–
GBP
|
1,800,000
GBP
|
–
GBP
|
–
GBP
|
1,800,000
GBP
|
77,600,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
3,800,000
GBP
|
–
GBP
|
77,600,000
GBP
|
| Other comprehensive income [abstract] | ||||||||||||||||||||||||||||
| Components of other comprehensive income that will not be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||||||||||||
| Other comprehensive income, before tax, gains (losses) on revaluation of property, plant and equipment, right-of-use assets and intangible assets | — | — | — | — | — | — | — | — | — | — | — | — |
3,700,000
GBP
|
— |
400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans | — | — | — | — | — | — | — | — | — | — | — | — |
2,700,000
GBP
|
— |
4,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||||||||||||||
| Income tax relating to changes in revaluation surplus of property, plant and equipment, right-of-use assets and intangible assets included in other comprehensive income | — | — | — | — | — | — | — | — | — | — | — | — |
1,300,000
GBP
|
— |
200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — | — | — | — | — | — | — | — | — | — |
400,000
GBP
|
— |
400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Other comprehensive income |
–
GBP
|
2,400,000
GBP
|
4,700,000
GBP
|
–
GBP
|
2,300,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
2,300,000
GBP
|
2,300,000
GBP
|
–
GBP
|
4,700,000
GBP
|
2,300,000
GBP
|
3,500,000
GBP
|
3,700,000
GBP
|
–
GBP
|
3,700,000
GBP
|
–
GBP
|
–
GBP
|
3,700,000
GBP
|
3,700,000
GBP
|
–
GBP
|
200,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
3,500,000
GBP
|
| Comprehensive income | — | — | — | — | — | — | — | — | — | — | — | — |
258,500,000
GBP
|
— |
84,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Comprehensive income attributable to [abstract] | ||||||||||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — | — | — | — | — | — | — |
257,000,000
GBP
|
— |
81,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — | — | — | — | — | — | — | — |
1,500,000
GBP
|
— |
3,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |