Retirement benefit schemes - additional information (Details) - GBP (£) £ in Millions |
6 Months Ended | ||
|---|---|---|---|
Jun. 30, 2025 |
Dec. 31, 2024 |
Jun. 30, 2024 |
|
| Disclosure of defined benefit plans [abstract] | |||
| Percentage of principal schemes to total defined benefit schemes | 90.00% | ||
| Percentage of defined benefit net costs charged to the adjusted profit | 60.00% | ||
| Frequency of valuations | 3 years | ||
| Net asset and (liability) for pension and healthcare schemes | £ 72 | £ 117 | £ 88 |