Statement Of Comprehensive Income [Abstract]
| Concept |
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 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||
| Profit (loss) |
–
GBP
|
12,000,000
GBP
|
–
GBP
|
11,000,000
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
1,000,000
GBP
|
–
GBP
|
–
GBP
|
558,000,000
GBP
|
546,000,000
GBP
|
–
GBP
|
–
GBP
|
1,000,000
GBP
|
558,000,000
GBP
|
11,000,000
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 | — |
139,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
793,000,000
GBP
|
— | — | — | — | — | — |
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||
| Exchange differences on translation [abstract] | ||||||||||||||||||
| Gains (losses) on exchange differences on translation of foreign operations, before tax | — |
35,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
36,000,000
GBP
|
— | — | — | — | — | — |
| Reclassification adjustments on exchange differences on translation of foreign operations, before tax | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
-
GBP
|
— | — | — | — | — | — |
| Cash flow hedges [abstract] | ||||||||||||||||||
| Gains (losses) on cash flow hedges, before tax | — |
40,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
85,000,000
GBP
|
— | — | — | — | — | — |
| Reclassification adjustments on cash flow hedges, before tax | — |
28,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
78,000,000
GBP
|
— | — | — | — | — | — |
| Share of other comprehensive income of associates and joint ventures accounted for using equity method that will be reclassified to profit or loss, before tax | — |
27,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
57,000,000
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 | — |
3,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,000,000
GBP
|
— | — | — | — | — | — |
| Other comprehensive income |
–
GBP
|
215,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
170,000,000
GBP
|
–
GBP
|
215,000,000
GBP
|
45,000,000
GBP
|
–
GBP
|
809,000,000
GBP
|
809,000,000
GBP
|
41,000,000
GBP
|
–
GBP
|
–
GBP
|
850,000,000
GBP
|
–
GBP
|
–
GBP
|
| Comprehensive income |
–
GBP
|
203,000,000
GBP
|
–
GBP
|
11,000,000
GBP
|
–
GBP
|
169,000,000
GBP
|
–
GBP
|
214,000,000
GBP
|
45,000,000
GBP
|
–
GBP
|
1,367,000,000
GBP
|
1,355,000,000
GBP
|
41,000,000
GBP
|
–
GBP
|
1,000,000
GBP
|
1,408,000,000
GBP
|
11,000,000
GBP
|
–
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — |
214,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
1 ,367
GBP
|
— | — | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — |
–
GBP
|
— | — | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — |