Dividends on ordinary shares - Narrative (Details) - GBP (£) £ / shares in Units, £ in Millions |
3 Months Ended | 6 Months Ended | 12 Months Ended | |
|---|---|---|---|---|
Sep. 30, 2026 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Share buyback | Maximum | Future commitments | ||||
| Disclosure of classes of share capital [line items] | ||||
| Increase (decrease) through treasury share transactions, equity | £ 1,000 | |||
| Ordinary shares | ||||
| Disclosure of classes of share capital [line items] | ||||
| Interim dividends, per share (in GBP per share) | £ 0.059 | £ 0.030 | £ 0.056 | |
| Number of shares comprising, one american depository share (in shares) | 4 | |||
| Qualifying American depository shares | ||||
| Disclosure of classes of share capital [line items] | ||||
| Interim dividends, per share (in GBP per share) | £ 0.236 | |||