Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||||
| Property, plant and equipment [abstract] | ||||
| Property, plant and equipment |
1,513,000,000
GBP
|
1,548,000,000
GBP
|
— | — |
| Intangible assets and goodwill [abstract] | ||||
| Intangible assets and goodwill |
1,550,000,000
GBP
|
1,545,000,000
GBP
|
— | — |
| Investments accounted for using equity method [abstract] | ||||
| Investments in joint ventures accounted for using equity method |
252,000,000
GBP
|
201,000,000
GBP
|
— | — |
| Categories of financial assets [abstract] | ||||
| Financial assets at fair value through other comprehensive income [abstract] | ||||
| Financial assets at fair value through other comprehensive income |
6,024,000,000
GBP
|
5,851,000,000
GBP
|
— | — |
| Cash and cash equivalents [abstract] | ||||
| Cash and cash equivalents |
46,484,000,000
GBP
|
49,254,000,000
GBP
|
46,697,000,000
GBP
|
27,871,000,000
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 |
49,000,000
GBP
|
—
GBP
|
— | — |
| Miscellaneous assets [abstract] | ||||
| Net defined benefit asset |
1,050,000,000
GBP
|
1,572,000,000
GBP
|
— | — |
| Derivative financial assets |
2,407,000,000
GBP
|
1,681,000,000
GBP
|
— | — |
| Loans and advances | — | — | — | — |
| Loans and advances to banks |
992,000,000
GBP
|
1,169,000,000
GBP
|
— | — |
| Loans and advances to customers |
219,716,000,000
GBP
|
210,094,000,000
GBP
|
— | — |
| Cash and bank balances at central banks |
44,190,000,000
GBP
|
48,139,000,000
GBP
|
41,250,000,000
GBP
|
— |
| Mandatory reserve deposits at central banks |
2,223,000,000
GBP
|
2,498,000,000
GBP
|
1,839,000,000
GBP
|
— |
| Bank balances at central banks other than mandatory reserve deposits |
41,967,000,000
GBP
|
45,641,000,000
GBP
|
39,411,000,000
GBP
|
— |
| Reverse repurchase agreements and cash collateral on securities borrowed |
7,348,000,000
GBP
|
12,683,000,000
GBP
|
— | — |
| Other assets |
2,016,000,000
GBP
|
1,500,000,000
GBP
|
— | — |
| Miscellaneous liabilities [abstract] | ||||
| Net defined benefit liability |
25,000,000
GBP
|
37,000,000
GBP
|
— | — |
| Derivative financial liabilities |
951,000,000
GBP
|
777,000,000
GBP
|
— | — |
| Deposit liabilities | — | — | — | — |
| Deposits from banks |
28,525,000,000
GBP
|
33,855,000,000
GBP
|
— | — |
| Deposits from customers [abstract] | ||||
| Deposits from customers |
195,568,000,000
GBP
|
192,926,000,000
GBP
|
— | — |
| Subordinated liabilities [abstract] | ||||
| Subordinated liabilities |
2,332,000,000
GBP
|
2,228,000,000
GBP
|
— | — |
| Debt instruments issued |
31,531,000,000
GBP
|
25,520,000,000
GBP
|
— | — |
| Repurchase agreements and cash collateral on securities lent |
7,982,000,000
GBP
|
11,718,000,000
GBP
|
— | — |
| Other liabilities |
2,581,000,000
GBP
|
2,067,000,000
GBP
|
— | — |
| Issued capital [abstract] | ||||
| Issued capital |
3,105,000,000
GBP
|
3,105,000,000
GBP
|
— | — |
| Retained earnings [abstract] | ||||
| Retained earnings |
4,848,000,000
GBP
|
5,053,000,000
GBP
|
— | — |
| Net assets (liabilities) [abstract] | ||||
| Assets |
285,213,000,000
GBP
|
287,098,000,000
GBP
|
— | — |
| Liabilities |
270,806,000,000
GBP
|
270,996,000,000
GBP
|
— | — |
| Assets less current liabilities [abstract] |