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 |
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 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||
| Profit (loss) |
—
GBP
|
—
GBP
|
1,632,000,000
GBP
|
—
GBP
|
1 , 6 1 9
GBP
|
—
GBP
|
1,632,000,000
GBP
|
13,000,000
GBP
|
—
GBP
|
9,000,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
83,000,000
GBP
|
92,000,000
GBP
|
83,000,000
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 | — | — | — | — |
29,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
71,000,000
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 | — | — | — | — |
7,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
1 9
GBP
|
— |
| Other comprehensive income |
—
GBP
|
—
GBP
|
44,000,000
GBP
|
20,000,000
GBP
|
44,000,000
GBP
|
—
GBP
|
24,000,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
13,000,000
GBP
|
—
GBP
|
37,000,000
GBP
|
37,000,000
GBP
|
50,000,000
GBP
|
| Comprehensive income |
—
GBP
|
—
GBP
|
1,588,000,000
GBP
|
20,000,000
GBP
|
1 , 5 7 5
GBP
|
—
GBP
|
1 , 6 0 8
GBP
|
13,000,000
GBP
|
—
GBP
|
9,000,000
GBP
|
—
GBP
|
—
GBP
|
—
GBP
|
1 3
GBP
|
—
GBP
|
120,000,000
GBP
|
129,000,000
GBP
|
13 3
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — |
1, 588
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
120,000,000
GBP
|
— |
| Comprehensive income, attributable to non-controlling interests | — | — | — | — |
13,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
9,000,000
GBP
|
— |