Statement Of Financial Position [Abstract]
| Concept |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||||||||
| Property, plant and equipment |
83,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
113,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Right-of-use assets |
73,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
76,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Investment property |
278,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
317,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners |
40,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
41,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current tax assets |
71,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
14,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets |
62,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
—
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents |
1,003,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
955,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Assets |
8,354,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
9,308,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||||||||
| Equity |
2,280,500,000
GBP
|
567,800,000
GBP
|
346,500,000
GBP
|
143,100,000
GBP
|
39,000,000
GBP
|
100,000
GBP
|
1,934,000,000
GBP
|
194,700,000
GBP
|
1,456,900,000
GBP
|
41,400,000
GBP
|
1,454,800,000
GBP
|
982,900,000
GBP
|
2,896,700,000
GBP
|
346,500,000
GBP
|
9,000,000
GBP
|
2,550,200,000
GBP
|
300,000
GBP
|
145,200,000
GBP
|
1,056,100,000
GBP
|
2,699,700,000
GBP
|
148,900,000
GBP
|
83,900,000
GBP
|
346,500,000
GBP
|
—
GBP
|
40,300,000
GBP
|
3,046,200,000
GBP
|
1,451,100,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||||||||
| Trade and other payables |
457,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
457,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Provisions [abstract] | |||||||||||||||||||||||||||
| Other provisions |
64,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
96,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Insurance contracts issued that are liabilities |
3,654,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
3,680,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities |
—
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities |
6,074,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
6,411,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities |
8,354,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — |
9,308,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — |