Statement Of Cash Flows [Abstract]
| Concept |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
2019-01-01 to 2019-12-31 |
|---|---|---|---|
| Statement of cash flows [abstract] | |||
| Cash flows from (used in) operating activities [abstract] | |||
| Income taxes paid (refund), classified as operating activities |
427,000,000
GBP
|
159,000,000
GBP
|
292,000,000
GBP
|
| Cash flows from (used in) operating activities |
10,846,000,000
GBP
|
18,823,000,000
GBP
|
4,030,000,000
GBP
|
| Cash flows from (used in) investing activities [abstract] | |||
| Cash flows from (used in) investing activities |
3,077,000,000
GBP
|
6,636,000,000
GBP
|
2,890,000,000
GBP
|
| Cash flows from (used in) financing activities [abstract] | |||
| Proceeds from issuing other equity instruments |
210,000,000
GBP
|
—
GBP
|
500,000,000
GBP
|
| Payments of lease liabilities, classified as financing activities |
25,000,000
GBP
|
45,000,000
GBP
|
54,000,000
GBP
|
| Dividends paid, classified as financing activities |
1,358,000,000
GBP
|
129,000,000
GBP
|
315,000,000
GBP
|
| Cash flows from (used in) financing activities |
10,753,000,000
GBP
|
6,773,000,000
GBP
|
4,180,000,000
GBP
|
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes |
3,170,000,000
GBP
|
18,686,000,000
GBP
|
2,740,000,000
GBP
|
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||
| Effect of exchange rate changes on cash and cash equivalents |
18,000,000
GBP
|
45,000,000
GBP
|
53,000,000
GBP
|