Statement Of Changes In Net Assets Available For Benefits [Abstract]
| Concept |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2023-01-01 to 2023-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
2022-01-01 to 2022-12-31 |
|---|---|---|---|---|---|---|
| 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] | ||||||
| Investment income |
7,000,000
GBP
|
—
GBP
|
7,000,000
GBP
|
4,700,000
GBP
|
—
GBP
|
4,700,000
GBP
|
| Administrative expenses |
275,800,000
GBP
|
—
GBP
|
275,800,000
GBP
|
264,300,000
GBP
|
—
GBP
|
264,300,000
GBP
|
| Tax expense (income) |
44,600,000
GBP
|
6,200,000
GBP
|
50,800,000
GBP
|
41,800,000
GBP
|
6,100,000
GBP
|
47,900,000
GBP
|