Statement Of Changes In Net Assets Available For Benefits [Abstract]
| Concept |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
|---|---|---|---|
| Statement of changes in net assets available for benefits [abstract] | |||
| Reconciliation of changes in net assets available for benefits [abstract] | |||
| Changes in net assets available for benefits [abstract] | |||
| Employer contributions |
500,000,000
GBP
|
— | — |
| Administrative expenses | — |
1,660,000,000
GBP
|
1,476,000,000
GBP
|
| Tax expense (income) | — |
976,000,000
GBP
|
66,000,000
GBP
|