Statement Of Comprehensive Income [Abstract]
| Concept |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||
| Profit (loss) |
13,000,000
GBP
|
—
GBP
|
—
GBP
|
347,000,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
360,000,000
GBP
|
360,000,000
GBP
|
—
GBP
|
—
GBP
|
309,000,000
GBP
|
—
GBP
|
12,000,000
GBP
|
297,000,000
GBP
|
—
GBP
|
297,000,000
GBP
|
—
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 | — | — | — |
52,000,000
GBP
|
— | — | — | — | — | — | — |
124,000,000
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 | — | — | — |
13,000,000
GBP
|
— | — | — | — | — | — | — |
28,000,000
GBP
|
— | — | — | — | — | — |
| Other comprehensive income |
1,000,000
GBP
|
—
GBP
|
—
GBP
|
23,000,000
GBP
|
—
GBP
|
—
GBP
|
15,000,000
GBP
|
39,000,000
GBP
|
24,000,000
GBP
|
—
GBP
|
—
GBP
|
108,000,000
GBP
|
—
GBP
|
4,000,000
GBP
|
96,000,000
GBP
|
—
GBP
|
104,000,000
GBP
|
8,000,000
GBP
|
| Comprehensive income |
12,000,000
GBP
|
—
GBP
|
—
GBP
|
324,000,000
GBP
|
—
GBP
|
—
GBP
|
15,000,000
GBP
|
321,000,000
GBP
|
336,000,000
GBP
|
—
GBP
|
—
GBP
|
201,000,000
GBP
|
—
GBP
|
8,000,000
GBP
|
201,000,000
GBP
|
—
GBP
|
193,000,000
GBP
|
8,000,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — |
336,000,000
GBP
|
— | — | — | — | — | — | — |
193,000,000
GBP
|
— | — | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — |
12,000,000
GBP
|
— | — | — | — | — | — | — |
8,000,000
GBP
|
— | — | — | — | — | — |