Leases - Summary of information about leases of lessor in cash flow statement (Detail) - GBP (£) £ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disclosure of quantitative information about leases for lessor [abstract] | |||
| Cash inflow for leases as a lessor | £ 21 | £ 22 | £ 19 |