Treasury shares - Schedule of Treasury Shares (Detail) - GBP (£) shares in Thousands, £ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Treasury shares transaction [line items] | |||
| Beginning Balance | £ 7 | ||
| Ending Balance | £ 9 | £ 7 | |
| Treasury shares [member] | |||
| Treasury shares transaction [line items] | |||
| Beginning Balance | 679 | 2,160 | |
| Purchase of treasury shares | 5,109 | 3,273 | |
| Release of treasury shares | (5,063) | (4,754) | |
| Ending Balance | 725 | 679 | 2,160 |
| Beginning Balance | £ 7 | £ 19 | |
| Purchase of treasury shares | 63 | 33 | |
| Release of treasury shares | (61) | (45) | £ (31) |
| Ending Balance | £ 9 | £ 7 | £ 19 |