Disclosure Of Income Tax [Text Block]
| Concept |
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 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
|---|---|---|---|---|---|---|---|---|
| Disclosure of income tax [text block] | — | — | — | — | — | — | — | — |
| Major components of tax expense (income) [abstract] | ||||||||
| Tax expense (income) | — | — |
976,000,000
GBP
|
— | — |
66,000,000
GBP
|
— | — |
| Income tax relating to components of other comprehensive income [abstract] | ||||||||
| Income tax relating to cash flow hedges included in other comprehensive income |
48,000,000
GBP
|
— | — | — | — | — |
58,000,000
GBP
|
— |
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — |
158,000,000
GBP
|
35,000,000
GBP
|
— | — | — |
| Income tax relating to financial assets measured at fair value through other comprehensive income included in other comprehensive income | — |
8,000,000
GBP
|
— | — | — | — | — |
17,000,000
GBP
|
| Reconciliation of accounting profit multiplied by applicable tax rates [abstract] |