Statement Of Cash Flows [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
As at 2023-12-31 |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-10-27 to 2022-10-27 |
As at 2021-12-31 |
|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||||
| Cash flows from (used in) operating activities [abstract] | ||||||
| Dividends received, classified as operating activities |
2,364,000,000
GBP
|
— | — |
2,220,000,000
GBP
|
— | — |
| Interest paid, classified as operating activities |
204,000,000
GBP
|
— | — |
88,000,000
GBP
|
— | — |
| Interest received, classified as operating activities |
3,086,000,000
GBP
|
— | — |
2,529,000,000
GBP
|
— | — |
| Income taxes paid (refund), classified as operating activities |
250,000,000
GBP
|
— | — |
268,000,000
GBP
|
— | — |
| Cash flows from (used in) operating activities |
2,016,000,000
GBP
|
— | — |
504,000,000
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | ||||||
| Cash flows from losing control of subsidiaries or other businesses, classified as investing activities |
105,000,000
GBP
|
— | — |
429,000,000
GBP
|
— | — |
| Other cash payments to acquire interests in joint ventures, classified as investing activities |
81,000,000
GBP
|
— | — |
nil
GBP
|
— | — |
| Proceeds from sales of property, plant and equipment, classified as investing activities |
1,000,000
GBP
|
— | — |
1,000,000
GBP
|
— | — |
| Purchase of property, plant and equipment, classified as investing activities |
496,000,000
GBP
|
— | — |
573,000,000
GBP
|
— | — |
| Cash flows from (used in) investing activities |
603,000,000
GBP
|
— | — |
368,000,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | ||||||
| Proceeds from issuing other equity instruments |
9,000,000
GBP
|
— | — |
—
GBP
|
— | — |
| Payments to acquire or redeem entity's shares |
—
GBP
|
— | — |
503,000,000
GBP
|
503
GBP
|
— |
| Payments of lease liabilities, classified as financing activities |
25,000,000
GBP
|
— | — |
30,000,000
GBP
|
— | — |
| Interest paid, classified as financing activities |
189,000,000
GBP
|
— | — |
190,000,000
GBP
|
— | — |
| Cash flows from (used in) financing activities |
680,000,000
GBP
|
— | — |
1,202,000,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes |
733,000,000
GBP
|
— | — |
2,074,000,000
GBP
|
— | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | ||||||
| Effect of exchange rate changes on cash and cash equivalents |
27,000,000
GBP
|
— | — |
50,000,000
GBP
|
— | — |
| Cash and cash equivalents | — |
5,590,000,000
GBP
|
4,884,000,000
GBP
|
— | — |
6,908,000,000
GBP
|