v3.25.4
Share-Based Payments - Summary of Shares Granted under Restricted Share Arrangements (Detail) - Long-term incentive plan [member] - Restricted shares [member]
Unit_pure in Thousands
12 Months Ended
Dec. 31, 2025
GBP (£)
Dec. 31, 2024
GBP (£)
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Number of shares 3,893 6,262
Weighted average fair value £ 11.09 £ 8.96