Statement Of Changes In Equity [Abstract]
| Concept |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
2021-02-01 to 2022-01-31 |
As at 2022-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
As at 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
2020-02-01 to 2021-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||
| Equity |
50,000,000
GBP
|
— |
325,000,000
GBP
|
2,228,000,000
GBP
|
— | — |
4,025,000,000
GBP
|
— | — | — | — | — |
46,000,000
GBP
|
6,778,000,000
GBP
|
— |
196,000,000
GBP
|
361,000,000
GBP
|
332,000,000
GBP
|
2,228,000,000
GBP
|
3,630,000,000
GBP
|
6,571,000,000
GBP
|
23,000,000
GBP
|
— | — | — | — |
43,000,000
GBP
|
— | — | — | — | — |
2,994,000,000
GBP
|
332,000,000
GBP
|
2,228,000,000
GBP
|
228,000,000
GBP
|
43,000,000
GBP
|
23,000,000
GBP
|
5,802,000,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
843,000,000
GBP
|
–
GBP
|
843,000,000
GBP
|
106,000,000
GBP
|
737,000,000
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — |
592,000,000
GBP
|
–
GBP
|
–
GBP
|
592,000,000
GBP
|
— |
604,000,000
GBP
|
12,000,000
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
| Other comprehensive income | — |
179,000,000
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
16,000,000
GBP
|
–
GBP
|
163,000,000
GBP
|
— | — | — | — |
–
GBP
|
— | — | — | — | — | — | — |
166,000,000
GBP
|
–
GBP
|
–
GBP
|
44,000,000
GBP
|
— | — | — |
–
GBP
|
122,000,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
| Comprehensive income | — |
179,000,000
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
859,000,000
GBP
|
–
GBP
|
680,000,000
GBP
|
— | — | — | — |
–
GBP
|
— | — | — | — | — | — | — |
758,000,000
GBP
|
–
GBP
|
–
GBP
|
636,000,000
GBP
|
— | — | — |
–
GBP
|
122,000,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
254,000,000
GBP
|
–
GBP
|
254,000,000
GBP
|
— | — | — | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
— |
27,000,000
GBP
|
–
GBP
|
27,000,000
GBP
|
— | — | — | — |
–
GBP
|
— | — | — | — | — | — | — |
14,000,000
GBP
|
–
GBP
|
–
GBP
|
14,000,000
GBP
|
— | — | — |
–
GBP
|
–
GBP
|
–
GBP
|
— | — | — | — | — | — | — |