v3.26.1
Intangible assets - Schedule of Pre-tax discount rates and terminal growth rates used for impairment testing (Details)
Jun. 30, 2026
Jun. 30, 2025
United States    
Disclosure of information for cash-generating units [line items]    
Pre-tax discount rate 9.00% 10.00%
Terminal growth rate 2.00% 2.00%
United Kingdom    
Disclosure of information for cash-generating units [line items]    
Pre-tax discount rate 9.00% 11.00%
Terminal growth rate 2.00% 3.00%
Türkiye(1)    
Disclosure of information for cash-generating units [line items]    
Pre-tax discount rate 39.00% 27.00%
Terminal growth rate 11.00% 14.00%
Türkiye(1) | Beginning of forecast period    
Disclosure of information for cash-generating units [line items]    
Post-tax discount rate 29.00%  
Türkiye(1) | End of forecast period    
Disclosure of information for cash-generating units [line items]    
Post-tax discount rate 18.00%  
India    
Disclosure of information for cash-generating units [line items]    
Pre-tax discount rate 12.00% 13.00%
Terminal growth rate 4.00% 4.00%
Greater China    
Disclosure of information for cash-generating units [line items]    
Pre-tax discount rate 9.00% 9.00%
Terminal growth rate 2.00% 2.00%
Mexico    
Disclosure of information for cash-generating units [line items]    
Pre-tax discount rate 14.00% 13.00%
Terminal growth rate 4.00% 3.00%