Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment |
2,065,000,000
GBP
|
1,953,000,000
GBP
|
2,536,000,000
GBP
|
| Intangible assets and goodwill [abstract] | |||
| Intangible assets and goodwill |
1,815,000,000
GBP
|
1,877,000,000
GBP
|
1,615,000,000
GBP
|
| Investment property [abstract] | |||
| Investment property |
15,422,000,000
GBP
|
16,505,000,000
GBP
|
19,698,000,000
GBP
|
| Investments accounted for using equity method [abstract] | |||
| Investments accounted for using equity method |
287,000,000
GBP
|
413,000,000
GBP
|
469,000,000
GBP
|
| Categories of financial assets [abstract] | |||
| Loans and receivables |
3,908,000,000
GBP
|
3,234,000,000
GBP
|
5,880,000,000
GBP
|
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents |
5,590,000,000
GBP
|
4,884,000,000
GBP
|
6,908,000,000
GBP
|
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | |||
| Non-current assets or disposal groups classified as held for sale |
1,356,000,000
GBP
|
684,000,000
GBP
|
1,023,000,000
GBP
|
| Miscellaneous assets [abstract] | |||
| Net defined benefit asset |
19,000,000
GBP
|
155,000,000
GBP
|
38,000,000
GBP
|
| Derivative financial assets |
1,693,000,000
GBP
|
2,850,000,000
GBP
|
3,373,000,000
GBP
|
| Equity instruments held |
66,248,000,000
GBP
|
70,127,000,000
GBP
|
74,069,000,000
GBP
|
| Debt instruments held [abstract] | |||
| Debt instruments held |
70,683,000,000
GBP
|
62,821,000,000
GBP
|
81,059,000,000
GBP
|
| Miscellaneous liabilities [abstract] | |||
| Net defined benefit liability |
294,000,000
GBP
|
—
GBP
|
84,000,000
GBP
|
| Derivative financial liabilities |
2,910,000,000
GBP
|
4,185,000,000
GBP
|
2,689,000,000
GBP
|
| Issued capital [abstract] | |||
| Issued capital |
119,000,000
GBP
|
119,000,000
GBP
|
130,000,000
GBP
|
| Retained earnings [abstract] | |||
| Retained earnings |
15,223,000,000
GBP
|
15,504,000,000
GBP
|
18,469,000,000
GBP
|
| Net assets (liabilities) [abstract] | |||
| Assets |
189,622,000,000
GBP
|
191,158,000,000
GBP
|
219,383,000,000
GBP
|
| Liabilities |
185,538,000,000
GBP
|
186,847,000,000
GBP
|
212,119,000,000
GBP
|
| Assets less current liabilities [abstract] |