Statement Of Changes In Equity [Abstract]
| Concept |
As at 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 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||||||||
| Equity |
2,280,500,000
GBP
|
— | — | — | — | — | — |
567,800,000
GBP
|
39,000,000
GBP
|
143,100,000
GBP
|
100,000
GBP
|
346,500,000
GBP
|
194,700,000
GBP
|
1,934,000,000
GBP
|
— | — |
1,456,900,000
GBP
|
— |
41,400,000
GBP
|
1,454,800,000
GBP
|
982,900,000
GBP
|
— | — |
2,896,700,000
GBP
|
346,500,000
GBP
|
— | — |
9,000,000
GBP
|
— | — |
2,550,200,000
GBP
|
— |
300,000
GBP
|
145,200,000
GBP
|
— | — |
1,056,100,000
GBP
|
2,699,700,000
GBP
|
148,900,000
GBP
|
83,900,000
GBP
|
346,500,000
GBP
|
—
GBP
|
40,300,000
GBP
|
3,046,200,000
GBP
|
1,451,100,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — |
—
GBP
|
—
GBP
|
39,500,000
GBP
|
39,500,000
GBP
|
—
GBP
|
—
GBP
|
— | — | — | — | — | — | — |
—
GBP
|
39,500,000
GBP
|
— |
—
GBP
|
— | — | — |
—
GBP
|
343,700,000
GBP
|
— | — |
—
GBP
|
—
GBP
|
— |
—
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
343,700,000
GBP
|
343,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income | — |
—
GBP
|
—
GBP
|
210,800,000
GBP
|
7,300,000
GBP
|
—
GBP
|
203,700,000
GBP
|
— | — | — | — | — | — | — |
—
GBP
|
210,800,000
GBP
|
— |
200,000
GBP
|
— | — | — |
—
GBP
|
72,200,000
GBP
|
— | — |
—
GBP
|
74,900,000
GBP
|
— |
300,000
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
72,200,000
GBP
|
3,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Comprehensive income | — |
—
GBP
|
—
GBP
|
250,300,000
GBP
|
46,800,000
GBP
|
—
GBP
|
203,700,000
GBP
|
— | — | — | — | — | — | — |
—
GBP
|
250,300,000
GBP
|
— |
200,000
GBP
|
— | — | — |
—
GBP
|
271,500,000
GBP
|
— | — |
—
GBP
|
74,900,000
GBP
|
— |
300,000
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
271,500,000
GBP
|
346,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — |
—
GBP
|
—
GBP
|
314,500,000
GBP
|
314,500,000
GBP
|
—
GBP
|
—
GBP
|
— | — | — | — | — | — | — |
—
GBP
|
314,500,000
GBP
|
— |
—
GBP
|
— | — | — |
—
GBP
|
317,400,000
GBP
|
— | — |
—
GBP
|
—
GBP
|
— |
—
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
317,400,000
GBP
|
317,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — |
—
GBP
|
—
GBP
|
9,500,000
GBP
|
9,500,000
GBP
|
—
GBP
|
—
GBP
|
— | — | — | — | — | — | — |
—
GBP
|
9,500,000
GBP
|
— |
—
GBP
|
— | — | — |
—
GBP
|
17,000,000
GBP
|
— | — |
—
GBP
|
—
GBP
|
— |
—
GBP
|
—
GBP
|
— |
—
GBP
|
— | — |
17,000,000
GBP
|
17,000,000
GBP
|
— | — | — | — | — | — | — | — | — |