v3.25.2
Report of the directors financial review risk report - The consensus Upside scenario (Details) - Upside scenario
 6 Months Ended 12 Months Ended
Jun. 30, 2025
Dec. 31, 2024
Disclosure of financial assets [line items]    
Central bank policy rate (%, min) 10.00% 10.00%
– United Kingdom    
Disclosure of financial assets [line items]    
Central bank policy rate (%, min) 10.00% 10.00%
– United Kingdom | Not later than one year    
Disclosure of financial assets [line items]    
GDP level (%, start-to-peak) 11.00% 11.30%
– United Kingdom | Later than one year and not later than two years    
Disclosure of financial assets [line items]    
Unemployment rate (%, min) 3.00% 3.50%
House price index (%, start-to-peak) 18.20% 24.20%
Inflation rate (YoY % change, min) 3.30% 1.40%
Central bank policy rate (%, min) 4.30% 3.60%
– France    
Disclosure of financial assets [line items]    
Central bank policy rate (%, min) 10.00% 10.00%
– France | Not later than one year    
Disclosure of financial assets [line items]    
GDP level (%, start-to-peak) 8.40% 8.90%
– France | Later than one year and not later than two years    
Disclosure of financial assets [line items]    
Unemployment rate (%, min) 6.60% 6.40%
House price index (%, start-to-peak) 23.30% 22.80%
Inflation rate (YoY % change, min) 2.30% 0.10%
Central bank policy rate (%, min) 2.50% 1.40%