Statement Of Changes In Equity [Abstract]
| Concept |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 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 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 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 |
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 |
2021-01-01 to 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity | — |
51,000,000
GBP
|
7,556,000,000
GBP
|
66,000,000
GBP
|
— | — | — |
19,454,000,000
GBP
|
— |
941,000,000
GBP
|
200,000,000
GBP
|
10,308,000,000
GBP
|
—
GBP
|
— | — | — | — | — | — | — | — | — |
19,202,000,000
GBP
|
252,000,000
GBP
|
314,000,000
GBP
|
— | — | — | — | — |
7,468,000,000
GBP
|
1,006,000,000
GBP
|
— | — | — |
19,554,000,000
GBP
|
— | — | — |
6,000,000
GBP
|
862,000,000
GBP
|
212,000,000
GBP
|
— |
10,260,000,000
GBP
|
20,560,000,000
GBP
|
— |
200,000,000
GBP
|
— |
—
GBP
|
— | — | — |
982,000,000
GBP
|
— |
980,000,000
GBP
|
101,000,000
GBP
|
977,000,000
GBP
|
814,000,000
GBP
|
10,257,000,000
GBP
|
200,000,000
GBP
|
18,685,000,000
GBP
|
5,065,000,000
GBP
|
7,000,000
GBP
|
17,708,000,000
GBP
|
500,000,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) |
70,000,000
GBP
|
— | — | — | — | — |
1,966,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
2,036,000,000
GBP
|
1,966,000,000
GBP
|
— |
2,910,000,000
GBP
|
— | — | — | — | — | — | — | — |
2,798,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
112,000,000
GBP
|
— | — |
2,798,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — | — | — | — | — |
241,000,000
GBP
|
— | — | — | — | — | — |
377,000,000
GBP
|
23,000,000
GBP
|
100,000,000
GBP
|
— |
33,000,000
GBP
|
344,000,000
GBP
|
221,000,000
GBP
|
— | — | — |
136,000,000
GBP
|
— |
34,000,000
GBP
|
214,000,000
GBP
|
47,000,000
GBP
|
— | — |
97,000,000
GBP
|
— |
201,000,000
GBP
|
— | — | — |
13,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
221,000,000
GBP
|
— |
171,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Comprehensive income | — | — | — | — | — | — | — | — |
1,459,000,000
GBP
|
— | — | — | — | — | — |
1,659,000,000
GBP
|
23,000,000
GBP
|
1,866,000,000
GBP
|
— |
37,000,000
GBP
|
1,622,000,000
GBP
|
221,000,000
GBP
|
— | — | — |
200,000,000
GBP
|
— |
146,000,000
GBP
|
1,252,000,000
GBP
|
2,751,000,000
GBP
|
— | — |
97,000,000
GBP
|
— |
1,645,000,000
GBP
|
— | — | — |
2,897,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — |
221,000,000
GBP
|
— |
2,627,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — | — | — | — | — | — |
1,127,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,127,000,000
GBP
|
1,127,000,000
GBP
|
— |
280,000,000
GBP
|
— | — | — | — | — | — | — | — |
280,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
280,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through changes in ownership interests in subsidiaries that do not result in loss of control, equity |
9,000,000
GBP
|
— | — | — | — |
—
GBP
|
—
GBP
|
— | — | — | — | — | — |
—
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
9,000,000
GBP
|
—
GBP
|
— |
54,000,000
GBP
|
— | — | — | — | — | — | — | — |
7,000,000
GBP
|
— | — | — | — |
—
GBP
|
— | — |
—
GBP
|
— |
61,000,000
GBP
|
— | — |
7,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — | — | — |
45,000,000
GBP
|
29,000,000
GBP
|
64,000,000
GBP
|
— | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — |
6,000,000
GBP
|
— | — | — | — | — | — |
64,000,000
GBP
|
3,000,000
GBP
|
— |
1,000,000
GBP
|
— | — | — | — |
2,000,000
GBP
|
— | — |
1,000,000
GBP
|
46,000,000
GBP
|
— | — | — | — |
51,000,000
GBP
|
— | — | — | — | — | — | — |
1,000,000
GBP
|
— | — |
3,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |