Intangible Assets - Product Development - Summary of Intangible Assets (Detail) - GBP (£) £ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Disclosure of reconciliation of changes in intangible assets and goodwill [line items] | ||
| Beginning balance | £ 947 | |
| Ending Balance | 822 | £ 947 |
| Cost [member] | ||
| Disclosure of reconciliation of changes in intangible assets and goodwill [line items] | ||
| Beginning balance | 2,514 | 2,517 |
| Exchange differences | (135) | 17 |
| Additions | 285 | 284 |
| Disposals and retirements | (38) | (309) |
| Transfers | 0 | 5 |
| Ending Balance | 2,626 | 2,514 |
| Depreciation [member] | ||
| Disclosure of reconciliation of changes in intangible assets and goodwill [line items] | ||
| Beginning balance | (1,567) | (1,570) |
| Exchange differences | 89 | (14) |
| Charge for the year | (276) | (287) |
| Impairment | (88) | (4) |
| Disposals and retirements | 38 | 309 |
| Transfers | 0 | (1) |
| Ending Balance | £ (1,804) | £ (1,567) |