Statement Of Cash Flows [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
As at 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 |
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 |
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 cash flows [abstract] | ||||||||||||||||||||
| Cash flows from (used in) operating activities [abstract] | ||||||||||||||||||||
| Profit (loss) |
381,000,000
GBP
|
— |
–
GBP
|
–
GBP
|
381,000,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
232,000,000
GBP
|
232,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
263,000,000
GBP
|
263,000,000
GBP
|
| Adjustments to reconcile profit (loss) [abstract] | ||||||||||||||||||||
| Adjustments for decrease (increase) in inventories |
15,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
4,000,000
GBP
|
— | — | — | — | — | — | — |
3,000,000
GBP
|
— |
| Other adjustments for non-cash items |
26,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
8,000,000
GBP
|
— | — | — | — | — | — | — |
6,000,000
GBP
|
— |
| Interest paid, classified as operating activities |
191,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
52,000,000
GBP
|
— | — | — | — | — | — | — |
42,000,000
GBP
|
— |
| Interest received, classified as operating activities |
25,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
13,000,000
GBP
|
— | — | — | — | — | — | — |
5,000,000
GBP
|
— |
| Income taxes paid (refund), classified as operating activities |
100,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
77,000,000
GBP
|
— | — | — | — | — | — | — |
69,000,000
GBP
|
— |
| Cash flows from (used in) operating activities |
737,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
600,000,000
GBP
|
— | — | — | — | — | — | — |
563,000,000
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | ||||||||||||||||||||
| Cash flows from losing control of subsidiaries or other businesses, classified as investing activities |
–
GBP
|
— | — | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
— |
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities |
242,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,018,000,000
GBP
|
— | — | — | — | — | — | — |
463,000,000
GBP
|
— |
| Proceeds from sales of property, plant and equipment, classified as investing activities |
14,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
5,000,000
GBP
|
— | — | — | — | — | — | — |
7,000,000
GBP
|
— |
| Purchase of property, plant and equipment, classified as investing activities |
167,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
153,000,000
GBP
|
— | — | — | — | — | — | — |
128,000,000
GBP
|
— |
| Purchase of intangible assets, classified as investing activities |
44,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
37,000,000
GBP
|
— | — | — | — | — | — | — |
32,000,000
GBP
|
— |
| Cash flows from (used in) investing activities |
416,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,197,000,000
GBP
|
— | — | — | — | — | — | — |
441,000,000
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | ||||||||||||||||||||
| Payments from changes in ownership interests in subsidiaries that do not result in loss of control |
–
GBP
|
— | — | — | — | — | — | — | — | — |
–
GBP
|
— | — | — | — | — | — | — |
9,000,000
GBP
|
— |
| Proceeds from borrowings, classified as financing activities |
–
GBP
|
— | — | — | — | — | — | — | — | — |
2,383,000,000
GBP
|
— | — | — | — | — | — | — |
5,000,000
GBP
|
— |
| Repayments of borrowings, classified as financing activities |
–
GBP
|
— | — | — | — | — | — | — | — | — |
844,000,000
GBP
|
— | — | — | — | — | — | — |
167,000,000
GBP
|
— |
| Payments of lease liabilities, classified as financing activities |
157,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
104,000,000
GBP
|
— | — | — | — | — | — | — |
88,000,000
GBP
|
— |
| Dividends paid, classified as financing activities |
201,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
122,000,000
GBP
|
— | — | — | — | — | — | — |
139,000,000
GBP
|
— |
| Cash flows from (used in) financing activities |
361,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,323,000,000
GBP
|
— | — | — | — | — | — | — |
417,000,000
GBP
|
— |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes |
40,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
726,000,000
GBP
|
— | — | — | — | — | — | — |
295,000,000
GBP
|
— |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | ||||||||||||||||||||
| Effect of exchange rate changes on cash and cash equivalents |
7,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
89,000,000
GBP
|
— | — | — | — | — | — | — |
14,000,000
GBP
|
— |
| Cash and cash equivalents | — |
1,562,000,000
GBP
|
— | — | — | — | — |
2,170,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |