Disclosure Of Analysis Of Other Comprehensive Income By Item [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 |
2020-01-01 to 2020-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
2019-01-01 to 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Disclosure of analysis of other comprehensive income by item [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Disclosure of analysis of other comprehensive income by item [abstract] | |||||||||||||||
| Disclosure of analysis of other comprehensive income by item [line items] | |||||||||||||||
| Other comprehensive income, net of tax, exchange differences on translation of foreign operations | — | — | — | — | — | — | — | — | — |
4,000,000
GBP
|
4,000,000
GBP
|
— |
4,000,000
GBP
|
— | — |
| Other comprehensive income, net of tax, cash flow hedges |
374,000,000
GBP
|
374,000,000
GBP
|
374,000,000
GBP
|
— | — |
110,000,000
GBP
|
— |
110,000,000
GBP
|
110,000,000
GBP
|
— |
115,000,000
GBP
|
— |
115,000,000
GBP
|
— |
115,000,000
GBP
|
| Other comprehensive income, net of tax, gains (losses) on remeasurements of defined benefit plans | — |
845,000,000
GBP
|
845,000,000
GBP
|
845,000,000
GBP
|
370,000,000
GBP
|
372,000,000
GBP
|
2,000,000
GBP
|
— |
370,000,000
GBP
|
— |
393,000,000
GBP
|
393,000,000
GBP
|
391,000,000
GBP
|
2,000,000
GBP
|
— |
| Other comprehensive income, net of tax, change in fair value of financial liability attributable to change in credit risk of liability | — | — |
—
GBP
|
— |
3,000,000
GBP
|
3,000,000
GBP
|
— | — |
3,000,000
GBP
|
— |
58,000,000
GBP
|
58,000,000
GBP
|
58,000,000
GBP
|
— | — |