Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||||||
| Intangible assets and goodwill [abstract] | |||||||
| Intangible assets and goodwill |
7,614,000,000
GBP
|
— |
7,116,000,000
GBP
|
— | — | — | — |
| Cash and cash equivalents [abstract] | |||||||
| Cash and cash equivalents |
118,824,000,000
GBP
|
— |
158,449,000,000
GBP
|
— |
190,706,000,000
GBP
|
— |
139,199,000,000
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 |
902,000,000
GBP
|
— |
6,861,000,000
GBP
|
— | — | — | — |
| Miscellaneous assets [abstract] | |||||||
| Derivative financial assets |
78,904,000,000
GBP
|
— |
99,545,000,000
GBP
|
— | — | — | — |
| Loans and advances | — | — | — | — | — | — | — |
| Loans and advances to banks |
6,914,000,000
GBP
|
— |
7,139,000,000
GBP
|
— | — | — | — |
| Loans and advances to customers |
381,433,000,000
GBP
|
— |
366,340,000,000
GBP
|
— | — | — | — |
| Cash and bank balances at central banks |
104,262,000,000
GBP
|
— |
144,832,000,000
GBP
|
— | — | — | — |
| Other assets |
8,760,000,000
GBP
|
— |
9,176,000,000
GBP
|
— | — | — | — |
| Current borrowings and current portion of non-current borrowings, by type [abstract] | |||||||
| Current notes and debentures issued and current portion of non-current notes and debentures issued |
3,237,000,000
GBP
|
— |
3,218,000,000
GBP
|
— | — | — | — |
| Miscellaneous liabilities [abstract] | |||||||
| Derivative financial liabilities |
72,395,000,000
GBP
|
— |
94,047,000,000
GBP
|
— | — | — | — |
| Deposit liabilities | — | — | — | — | — | — | — |
| Deposits from banks |
22,190,000,000
GBP
|
— |
20,441,000,000
GBP
|
— | — | — | — |
| Deposits from customers [abstract] | |||||||
| Deposits from customers |
431,377,000,000
GBP
|
— |
450,318,000,000
GBP
|
— | — | — | — |
| Subordinated liabilities [abstract] | |||||||
| Subordinated liabilities |
5,714,000,000
GBP
|
— |
6,260,000,000
GBP
|
— | — | — | — |
| Other liabilities |
5,202,000,000
GBP
|
— |
5,346,000,000
GBP
|
— | — | — | — |
| Miscellaneous equity [abstract] | |||||||
| Capital redemption reserve | — |
2,507,000,000
GBP
|
— |
1,651,000,000
GBP
|
— |
722,000,000
GBP
|
— |
| Net assets (liabilities) [abstract] | |||||||
| Assets |
692,673,000,000
GBP
|
— |
720,053,000,000
GBP
|
— | — | — | — |
| Liabilities |
655,485,000,000
GBP
|
— |
683,557,000,000
GBP
|
— | — | — | — |
| Assets less current liabilities [abstract] |