Other financial assets - Additional Information (Detail) - GBP (£) £ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disclosure of financial assets [line items] | |||
| Other financial assets | £ 125 | £ 141 | £ 143 |
| Disposal of investments | 0 | 0 | |
| Fair value movements – OCI [member] | |||
| Disclosure of financial assets [line items] | |||
| Other financial assets | 24 | 28 | |
| Disposal of investments | 0 | 0 | |
| Investments in unlisted securities [member] | |||
| Disclosure of financial assets [line items] | |||
| Other financial assets | 125 | 141 | |
| Fair value through profit or loss [member] | |||
| Disclosure of financial assets [line items] | |||
| Other financial assets | £ 101 | £ 113 | |