Statement Of Cash Flows [Abstract]
| Concept |
2024-01-01 to 2024-12-31 |
As at 2024-12-31 |
2024-01-01 to 2024-12-31 |
2024-01-01 to 2024-12-31 |
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 |
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 |
As at 2021-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||||||||||
| Cash flows from (used in) operating activities [abstract] | |||||||||||||
| Profit (loss) |
971,000,000
GBP
|
— |
971,000,000
GBP
|
971,000,000
GBP
|
1,541,000,000
GBP
|
— |
1,541,000,000
GBP
|
1,541,000,000
GBP
|
— |
1,394,000,000
GBP
|
1,394,000,000
GBP
|
1,394,000,000
GBP
|
— |
| Adjustments to reconcile profit (loss) [abstract] | |||||||||||||
| Adjustments for depreciation and amortisation expense |
300,000,000
GBP
|
— | — | — |
290,000,000
GBP
|
— | — | — | — | — |
296,000,000
GBP
|
— | — |
| Adjustments for impairment loss (reversal of impairment loss) recognised in profit or loss |
94,000,000
GBP
|
— | — | — |
195,000,000
GBP
|
— | — | — | — | — |
284,000,000
GBP
|
— | — |
| Adjustments for provisions |
689,000,000
GBP
|
— | — | — |
335,000,000
GBP
|
— | — | — | — | — |
419,000,000
GBP
|
— | — |
| Adjustments for unrealised foreign exchange losses (gains) |
53,000,000
GBP
|
— | — | — |
518,000,000
GBP
|
— | — | — | — | — |
1,383,000,000
GBP
|
— | — |
| Other adjustments for non-cash items |
65,000,000
GBP
|
— | — | — |
749,000,000
GBP
|
— | — | — | — | — |
1,497,000,000
GBP
|
— | — |
| Adjustments for losses (gains) on disposal of non-current assets |
31,000,000
GBP
|
— | — | — |
—
GBP
|
— | — | — | — | — |
—
GBP
|
— | — |
| Cash flows from (used in) operating activities |
3,331,000,000
GBP
|
— | — | — |
3,304,000,000
GBP
|
— | — | — | — | — |
3,992,000,000
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | |||||||||||||
| Cash flows from (used in) investing activities |
4,540,000,000
GBP
|
— | — | — |
2,747,000,000
GBP
|
— | — | — | — | — |
198,000,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | |||||||||||||
| Proceeds from issuing other equity instruments |
400,000,000
GBP
|
— | — | — |
—
GBP
|
— | — | — | — | — |
750,000,000
GBP
|
— | — |
| Payments of other equity instruments |
500,000,000
GBP
|
— | — | — |
—
GBP
|
— | — | — | — | — |
985,000,000
GBP
|
— | — |
| Payments of lease liabilities, classified as financing activities |
33,000,000
GBP
|
— | — | — |
47,000,000
GBP
|
— | — | — | — | — |
26,000,000
GBP
|
— | — |
| Cash flows from (used in) financing activities |
285,000,000
GBP
|
— | — | — |
19,000,000
GBP
|
— | — | — | — | — |
277,000,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes |
7,586,000,000
GBP
|
— | — | — |
6,032,000,000
GBP
|
— | — | — | — | — |
3,913,000,000
GBP
|
— | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||||||||||
| Effect of exchange rate changes on cash and cash equivalents |
14,000,000
GBP
|
— | — | — |
58,000,000
GBP
|
— | — | — | — | — |
69,000,000
GBP
|
— | — |
| Cash and cash equivalents | — |
29,181,000,000
GBP
|
— | — | — |
36,781,000,000
GBP
|
— | — |
42,871,000,000
GBP
|
— | — | — |
46,715,000,000
GBP
|