Leases - Summary of information about leases 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 lessee [abstract] | |||
| Cash outflow for leases as a lessee | £ 97 | £ 100 | £ 107 |