Statement Of Comprehensive Income [Abstract]
| Concept |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
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 |
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 |
2020-01-01 to 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | |||||||||||||||||
| Profit (loss) | — |
1,394,000,000
GBP
|
— |
1,394,000,000
GBP
|
1,394,000,000
GBP
|
19,000,000
GBP
|
— | — |
1,365,000,000
GBP
|
1,384,000,000
GBP
|
1,365,000,000
GBP
|
452,000,000
GBP
|
471,000,000
GBP
|
19,000,000
GBP
|
452,000,000
GBP
|
— | — |
| Other comprehensive income [abstract] | |||||||||||||||||
| Components of other comprehensive income that will not be reclassified to profit or loss, before tax [abstract] | |||||||||||||||||
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans | — | — | — |
722,000,000
GBP
|
— | — | — | — | — |
1,264,000,000
GBP
|
— | — |
505,000,000
GBP
|
— | — | — | — |
| Other comprehensive income, before tax, change in fair value of financial liability attributable to change in credit risk of liability | — | — | — |
29,000,000
GBP
|
— | — | — | — | — |
—
GBP
|
— | — |
3,000,000
GBP
|
— | — | — | — |
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | |||||||||||||||||
| Cash flow hedges [abstract] | |||||||||||||||||
| Gains (losses) on cash flow hedges, before tax | — | — | — |
425,000,000
GBP
|
— | — | — | — | — |
873,000,000
GBP
|
— | — |
971,000,000
GBP
|
— | — | — | — |
| Reclassification adjustments on cash flow hedges, before tax | — | — | — |
2,129,000,000
GBP
|
— | — | — | — | — |
358,000,000
GBP
|
— | — |
809,000,000
GBP
|
— | — | — | — |
| Financial assets measured at fair value through other comprehensive income [abstract] | |||||||||||||||||
| Gains (losses) on financial assets measured at fair value through other comprehensive income, before tax | — | — | — |
278,000,000
GBP
|
— | — | — | — | — |
111,000,000
GBP
|
— | — |
114,000,000
GBP
|
— | — | — | — |
| Reclassification adjustments on financial assets measured at fair value through other comprehensive income, before tax | — | — | — |
247,000,000
GBP
|
— | — | — | — | — |
110,000,000
GBP
|
— | — |
107,000,000
GBP
|
— | — | — | — |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | |||||||||||||||||
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — |
267,000,000
GBP
|
— | — | — | — | — |
419,000,000
GBP
|
— | — |
133,000,000
GBP
|
— | — | — | — |
| Income tax relating to changes in fair value of financial liability attributable to change in credit risk of liability included in other comprehensive income | — | — | — |
9,000,000
GBP
|
— | — | — | — | — |
—
GBP
|
— | — |
—
GBP
|
— | — | — | — |
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract] | |||||||||||||||||
| Income tax relating to cash flow hedges included in other comprehensive income | — | — | — |
469,000,000
GBP
|
— | — | — | — | — |
141,000,000
GBP
|
— | — |
52,000,000
GBP
|
— | — | — | — |
| Income tax relating to financial assets measured at fair value through other comprehensive income included in other comprehensive income | — | — | — |
11,000,000
GBP
|
— | — | — | — | — |
2,000,000
GBP
|
— | — |
2,000,000
GBP
|
— | — | — | — |
| Other comprehensive income | — | — | — |
1,690,000,000
GBP
|
— | — | — | — | — |
468,000,000
GBP
|
— | — |
260,000,000
GBP
|
— | — | — | — |
| Comprehensive income |
1,235,000,000
GBP
|
296,000,000
GBP
|
20,000,000
GBP
|
296,000,000
GBP
|
959,000,000
GBP
|
19,000,000
GBP
|
374,000,000
GBP
|
3,000,000
GBP
|
1,833,000,000
GBP
|
1,852,000,000
GBP
|
2,210,000,000
GBP
|
79,000,000
GBP
|
211,000,000
GBP
|
17,000,000
GBP
|
194,000,000
GBP
|
110,000,000
GBP
|
5,000,000
GBP
|
| Comprehensive income attributable to [abstract] | |||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — |
296,000,000
GBP
|
— | — | — | — | — |
1,833,000,000
GBP
|
— | — |
194,000,000
GBP
|
— | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — |
—
GBP
|
— | — | — | — | — |
19,000,000
GBP
|
— | — |
17,000,000
GBP
|
— | — | — | — |