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 |
2021-01-01 to 2021-12-31 |
2020-01-01 to 2020-12-31 |
2020-01-01 to 2020-12-31 |
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] | ||||||
| Administrative expenses |
57,300,000
GBP
|
8,200,000
GBP
|
65,500,000
GBP
|
76,400,000
GBP
|
46,800,000
GBP
|
29,600,000
GBP
|
| Tax expense (income) |
9,200,000
GBP
|
1,500,000
GBP
|
7,700,000
GBP
|
3,100,000
GBP
|
3,800,000
GBP
|
700,000
GBP
|