Statement Of Cash Flows [Abstract]
| Concept |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||
| Cash flows from (used in) operating activities [abstract] | ||||
| Dividends received, classified as operating activities | — |
122,000,000
GBP
|
— |
122,000,000
GBP
|
| Interest paid, classified as operating activities | — |
1,000,000
GBP
|
— |
2,000,000
GBP
|
| Interest received, classified as operating activities | — |
22,000,000
GBP
|
— |
30,000,000
GBP
|
| Income taxes paid (refund), classified as operating activities | — |
22,000,000
GBP
|
— |
33,000,000
GBP
|
| Cash flows from (used in) operating activities | — |
14,000,000
GBP
|
— |
56,000,000
GBP
|
| Cash flows from (used in) investing activities [abstract] | ||||
| Cash flows from losing control of subsidiaries or other businesses, classified as investing activities | — |
112,000,000
GBP
|
— |
8,000,000
GBP
|
| Cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities | — |
145,000,000
GBP
|
— |
–
GBP
|
| Purchase of property, plant and equipment, classified as investing activities | — |
12,000,000
GBP
|
— |
13,000,000
GBP
|
| Purchase of intangible assets, classified as investing activities | — |
–
GBP
|
— |
12,000,000
GBP
|
| Income taxes paid (refund), classified as investing activities | — |
33,000,000
GBP
|
— |
33,000,000
GBP
|
| Cash flows from (used in) investing activities | — |
755,000,000
GBP
|
— |
1,014,000,000
GBP
|
| Cash flows from (used in) financing activities [abstract] | ||||
| Payments to acquire or redeem entity's shares | — |
41,000,000
GBP
|
— |
361,000,000
GBP
|
| Dividends paid, classified as financing activities | — |
308,000,000
GBP
|
— |
479,000,000
GBP
|
| Interest paid, classified as financing activities | — |
28,000,000
GBP
|
— |
30,000,000
GBP
|
| Cash flows from (used in) financing activities | — |
243,000,000
GBP
|
— |
1,064,000,000
GBP
|
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — |
526,000,000
GBP
|
— |
6,000,000
GBP
|
| Effect of exchange rate changes on cash and cash equivalents [abstract] | ||||
| Effect of exchange rate changes on cash and cash equivalents | — |
9,000,000
GBP
|
— |
5,000,000
GBP
|
| Cash and cash equivalents |
1,904,000,000
GBP
|
— |
1,519,000,000
GBP
|
— |