Statement Of Cash Flows [Abstract]
| Concept |
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 |
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 |
2021-01-01 to 2021-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||||||||||
| Cash flows from (used in) operating activities [abstract] | ||||||||||||
| Profit (loss) | — |
1,160,000,000
GBP
|
1,139,000,000
GBP
|
1,160,000,000
GBP
|
21,000,000
GBP
|
— |
70,000,000
GBP
|
— |
1,966,000,000
GBP
|
— |
2,036,000,000
GBP
|
1,966,000,000
GBP
|
| Cash flows from (used in) operations | — | — |
16,093,000,000
GBP
|
— | — | — | — | — | — | — |
2,554,000,000
GBP
|
— |
| Dividends received, classified as operating activities | — | — |
4,347,000,000
GBP
|
— | — | — | — | — | — | — |
4,461,000,000
GBP
|
— |
| Interest received, classified as operating activities | — | — |
4,335,000,000
GBP
|
— | — | — | — | — | — | — |
3,605,000,000
GBP
|
— |
| Income taxes paid (refund), classified as operating activities | — | — |
210,000,000
GBP
|
— | — | — | — | — | — | — |
304,000,000
GBP
|
— |
| Cash flows from (used in) operating activities | — | — |
15,883,000,000
GBP
|
— | — | — | — | — | — | — |
2,858,000,000
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | ||||||||||||
| Cash flows from losing control of subsidiaries or other businesses, classified as investing activities | — | — |
—
GBP
|
— | — | — | — | — | — | — |
23,000,000
GBP
|
— |
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities | — | — |
275,000,000
GBP
|
— | — | — | — | — | — | — |
—
GBP
|
— |
| Proceeds from sales of property, plant and equipment, classified as investing activities | — | — |
35,000,000
GBP
|
— | — | — | — | — | — | — |
159,000,000
GBP
|
— |
| Purchase of property, plant and equipment, classified as investing activities | — | — |
16,000,000
GBP
|
— | — | — | — | — | — | — |
86,000,000
GBP
|
— |
| Purchase of intangible assets, classified as investing activities | — | — |
83,000,000
GBP
|
— | — | — | — | — | — | — |
22,000,000
GBP
|
— |
| Cash flows from (used in) investing activities | — | — |
339,000,000
GBP
|
— | — | — | — | — | — | — |
74,000,000
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | ||||||||||||
| Proceeds from issuing shares | — | — |
17,000,000
GBP
|
— | — | — | — | — | — | — |
6,000,000
GBP
|
— |
| Proceeds from borrowings, classified as financing activities | — | — |
659,000,000
GBP
|
— | — | — | — | — | — | — |
229,000,000
GBP
|
— |
| Repayments of borrowings, classified as financing activities | — | — |
1,554,000,000
GBP
|
— | — |
1,002,000,000
GBP
|
— | — | — |
1,878,000,000
GBP
|
2,197,000,000
GBP
|
— |
| Payments of lease liabilities, classified as financing activities | — | — |
63,000,000
GBP
|
— | — | — | — | — | — | — |
71,000,000
GBP
|
— |
| Dividends paid, classified as financing activities | — | — |
828,000,000
GBP
|
— | — | — | — | — | — | — |
1,110,000,000
GBP
|
— |
| Interest paid, classified as financing activities | — | — |
450,000,000
GBP
|
— | — | — | — | — | — | — |
489,000,000
GBP
|
— |
| Cash flows from (used in) financing activities | — | — |
5,939,000,000
GBP
|
— | — | — | — | — | — | — |
4,402,000,000
GBP
|
— |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — | — |
9,605,000,000
GBP
|
— | — | — | — | — | — | — |
7,186,000,000
GBP
|
— |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | ||||||||||||
| Effect of exchange rate changes on cash and cash equivalents | — | — |
93,000,000
GBP
|
— | — | — | — | — | — | — |
196,000,000
GBP
|
— |
| Cash and cash equivalents |
22,505,000,000
GBP
|
— | — | — | — | — | — |
12,485,000,000
GBP
|
— | — | — | — |