Statement Of Financial Position [Abstract]
| Concept |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | ||||||||||||||||||||||||||||||||
| Assets [abstract] | ||||||||||||||||||||||||||||||||
| Property, plant and equipment |
1,757,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,563,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Right-of-use assets |
142,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
99,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets |
220,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
312,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents |
684,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
414,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
333,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Assets |
34,815,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
34,451,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | ||||||||||||||||||||||||||||||||
| Equity [abstract] | ||||||||||||||||||||||||||||||||
| Issued capital |
92,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings |
26,730,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
37,538,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Share premium |
–
GBP
|
— | — | — | — | — | — | — | — | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Other reserves |
11,537,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
11,632,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent |
16,331,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
26,355,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-controlling interests |
126,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
125,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
16,457,000,000
GBP
|
11,537,000,000
GBP
|
126,000,000
GBP
|
–
GBP
|
26,730,000,000
GBP
|
92,000,000
GBP
|
1,046,000,000
GBP
|
16,331,000,000
GBP
|
37,538,000,000
GBP
|
11,632,000,000
GBP
|
26,480,000,000
GBP
|
26,355,000,000
GBP
|
–
GBP
|
125,000,000
GBP
|
448,000,000
GBP
|
1,000,000
GBP
|
37,281,000,000
GBP
|
111,000,000
GBP
|
26,112,000,000
GBP
|
1,000,000
GBP
|
482,000,000
GBP
|
11,652,000,000
GBP
|
–
GBP
|
26,223,000,000
GBP
|
27,321,000,000
GBP
|
91,000,000
GBP
|
1,372,000,000
GBP
|
652,000,000
GBP
|
27,412,000,000
GBP
|
20,842,000,000
GBP
|
4,454,000,000
GBP
|
1,000,000
GBP
|
| Liabilities [abstract] | ||||||||||||||||||||||||||||||||
| Deferred tax liabilities |
3,601,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
3,357,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities |
18,358,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
7,971,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |