Statement Of Comprehensive Income [Abstract]
| Concept |
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 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||
| Profit (loss) |
—
GBP
|
39,500,000
GBP
|
—
GBP
|
39,500,000
GBP
|
39,500,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
343,700,000
GBP
|
—
GBP
|
343,700,000
GBP
|
343,700,000
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 remeasurements of defined benefit plans | — | — | — |
9,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
3,800,000
GBP
|
— |
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||
| Cash flow hedges [abstract] | ||||||||||||||||||
| Gains (losses) on cash flow hedges, before tax | — | — | — |
200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
300,000
GBP
|
— |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||||
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — |
2,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
800,000
GBP
|
— |
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract] | ||||||||||||||||||
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss | — | — | — |
67,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
17,100,000
GBP
|
— |
| Other comprehensive income |
—
GBP
|
210,800,000
GBP
|
—
GBP
|
210,800,000
GBP
|
7,300,000
GBP
|
—
GBP
|
200,000
GBP
|
—
GBP
|
203,700,000
GBP
|
74,900,000
GBP
|
300,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
72,200,000
GBP
|
—
GBP
|
72,200,000
GBP
|
3,000,000
GBP
|
| Comprehensive income |
—
GBP
|
250,300,000
GBP
|
—
GBP
|
250,300,000
GBP
|
46,800,000
GBP
|
—
GBP
|
200,000
GBP
|
—
GBP
|
203,700,000
GBP
|
74,900,000
GBP
|
300,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
271,500,000
GBP
|
—
GBP
|
271,500,000
GBP
|
346,700,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — |
250,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
271,500,000
GBP
|
— |