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 |
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 |
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 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||||||||||||||
| Cash flows from (used in) operating activities [abstract] | ||||||||||||||||
| Profit (loss) |
1,725,000,000
GBP
|
— |
22,000,000
GBP
|
1,703,000,000
GBP
|
1,703,000,000
GBP
|
— |
563,000,000
GBP
|
553,000,000
GBP
|
563,000,000
GBP
|
10,000,000
GBP
|
5,000,000
GBP
|
— |
1,041,000,000
GBP
|
1,046,000,000
GBP
|
1,041,000,000
GBP
|
— |
| Adjustments to reconcile profit (loss) [abstract] | ||||||||||||||||
| Adjustments for provisions |
132,000,000
GBP
|
— | — | — | — | — | — |
192,000,000
GBP
|
— | — | — | — | — |
104,000,000
GBP
|
— | — |
| Adjustments for unrealised foreign exchange losses (gains) |
4,426,000,000
GBP
|
— | — | — | — | — | — |
6,761,000,000
GBP
|
— | — | — | — | — |
4,926,000,000
GBP
|
— | — |
| Adjustments for share-based payments |
58,000,000
GBP
|
— | — | — | — | — | — |
46,000,000
GBP
|
— | — | — | — | — |
96,000,000
GBP
|
— | — |
| Adjustments for fair value losses (gains) |
62,000,000
GBP
|
— | — | — | — | — | — |
427,000,000
GBP
|
— | — | — | — | — |
82,000,000
GBP
|
— | — |
| Other adjustments for non-cash items |
165,000,000
GBP
|
— | — | — | — | — | — |
16,000,000
GBP
|
— | — | — | — | — |
198,000,000
GBP
|
— | — |
| Dividends received, classified as operating activities |
15,000,000
GBP
|
— | — | — | — | — | — |
7,000,000
GBP
|
— | — | — | — | — |
—
GBP
|
— | — |
| Interest paid, classified as operating activities |
17,267,000,000
GBP
|
— | — | — | — | — | — |
5,284,000,000
GBP
|
— | — | — | — | — |
2,919,000,000
GBP
|
— | — |
| Interest received, classified as operating activities |
19,288,000,000
GBP
|
— | — | — | — | — | — |
7,668,000,000
GBP
|
— | — | — | — | — |
4,285,000,000
GBP
|
— | — |
| Income taxes paid (refund), classified as operating activities |
140,000,000
GBP
|
— | — | — | — | — | — |
845,000,000
GBP
|
— | — | — | — | — |
581,000,000
GBP
|
— | — |
| Cash flows from (used in) operating activities |
3,630,000,000
GBP
|
— | — | — | — | — | — |
32,190,000,000
GBP
|
— | — | — | — | — |
15,303,000,000
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | ||||||||||||||||
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities |
1,161,000,000
GBP
|
— | — | — | — | — | — |
29,000,000
GBP
|
— | — | — | — | — |
85,000,000
GBP
|
— | — |
| Purchase of intangible assets, classified as investing activities |
125,000,000
GBP
|
— | — | — | — | — | — |
28,000,000
GBP
|
— | — | — | — | — |
45,000,000
GBP
|
— | — |
| Cash flows from (used in) investing activities |
12,800,000,000
GBP
|
— | — | — | — | — | — |
7,186,000,000
GBP
|
— | — | — | — | — |
6,059,000,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | ||||||||||||||||
| Cash flows from (used in) financing activities |
169,000,000
GBP
|
— | — | — | — | — | — |
1,902,000,000
GBP
|
— | — | — | — | — |
631,000,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes |
9,001,000,000
GBP
|
— | — | — | — | — | — |
41,278,000,000
GBP
|
— | — | — | — | — |
20,731,000,000
GBP
|
— | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | ||||||||||||||||
| Effect of exchange rate changes on cash and cash equivalents |
3,869,000,000
GBP
|
— | — | — | — | — | — |
7,706,000,000
GBP
|
— | — | — | — | — |
5,112,000,000
GBP
|
— | — |
| Cash and cash equivalents | — |
177,037,000,000
GBP
|
— | — | — |
189,907,000,000
GBP
|
— | — | — | — | — |
140,923,000,000
GBP
|
— | — | — |
125,304,000,000
GBP
|