Statement Of Cash Flows [Abstract]
| Concept |
As at 2022-12-31 |
2022-01-01 to 2022-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||||
| Cash flows from (used in) operating activities [abstract] | |||||||
| Cash flows from (used in) operating activities | — |
2,970,000,000
GBP
|
— |
10,251,000,000
GBP
|
— |
18,918,000,000
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | |||||||
| Cash flows from (used in) investing activities | — |
198,000,000
GBP
|
— |
3,077,000,000
GBP
|
— |
6,636,000,000
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | |||||||
| Proceeds from issuing other equity instruments | — |
750,000,000
GBP
|
— |
210,000,000
GBP
|
— |
—
GBP
|
— |
| Payments of other equity instruments | — |
985,000,000
GBP
|
— |
210,000,000
GBP
|
— |
—
GBP
|
— |
| Payments of lease liabilities, classified as financing activities | — |
26,000,000
GBP
|
— |
25,000,000
GBP
|
— |
45,000,000
GBP
|
— |
| Cash flows from (used in) financing activities | — |
277,000,000
GBP
|
— |
10,753,000,000
GBP
|
— |
6,773,000,000
GBP
|
— |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — |
2,891,000,000
GBP
|
— |
2,575,000,000
GBP
|
— |
18,781,000,000
GBP
|
— |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||||
| Effect of exchange rate changes on cash and cash equivalents | — |
121,000,000
GBP
|
— |
18,000,000
GBP
|
— |
45,000,000
GBP
|
— |
| Cash and cash equivalents |
46,484,000,000
GBP
|
— |
49,254,000,000
GBP
|
— |
46,697,000,000
GBP
|
— |
27,871,000,000
GBP
|