v3.26.1
Borrowings and derivative financial instrument - US$ Convertible Bond (Details)
R / shares in Units, $ / shares in Units, R in Millions, $ in Millions
 12 Months Ended
Nov. 21, 2023
R / $
R / shares
Nov. 21, 2023
R / $
$ / shares
Dec. 31, 2025
ZAR (R)
component
Dec. 31, 2025
ZAR (R)
$ / shares
Dec. 31, 2024
ZAR (R)
Dec. 31, 2023
ZAR (R)
Dec. 31, 2025
USD ($)
Reconciliation Of Changes In Borrowings [Abstract]              
Balance at beginning of the year     R 41,687   R 36,618 R 22,728  
Loans raised     7,912   8,278 14,431  
Interest charge     1,793   1,946 1,192  
Interest paid     (2,086)   (1,947) (1,175)  
Unwinding of amortised cost     640   688 359  
(Gain)/loss on foreign exchange differences     (4,020)   344 2,105  
Balance at end of the year     43,257   41,687 36,618  
Current portion of balance     (11,402) R (11,402) (552) (11,672)  
Non-current portion of balance     31,855 R 31,855 41,135 24,946  
Reconciliation Of Changes In Derivatives [Abstract]              
Balance at beginning of the year     0   3,810    
Initial recognition of derivative instrument     0   0 1,433  
Loss on foreign exchange differences     (155)   215 (1,973)  
Balance at end of the year     R 0   0 3,810  
US$ Convertible bond, derivative              
Disclosure of detailed information about borrowings [line items]              
Conversion premium (as a percent)     32.50%        
Weighted average share price (in USD/ZAR per share) | (per share) R 18.55 $ 1.0088          
Exchange rates (in ZAR per USD) | R / $ 18.388 18.388          
Initial conversion price (USD per share) | $ / shares       R 1.3367      
Number of components | component     2        
Reconciliation Of Changes In Derivatives [Abstract]              
Balance at beginning of the year     R 0   3,810 0  
Initial recognition of derivative instrument     0   0 1,673  
Transfer to equity     0   (2,009) 0  
(Gain)/loss on financial instruments     0   (1,733) 2,136  
Loss on foreign exchange differences     0   (68) 1  
Balance at end of the year     0   0 3,810  
Current portion of balance     0 R 0 0 (3,810)  
Non-current portion of balance     R 0 R 0 0 0  
US$ Convertible bond              
Disclosure of detailed information about borrowings [line items]              
Face amount of debt | $             $ 500
Interest rate (as a percent)     4.25% 4.25%     4.25%
Term of facility     5 years        
Reconciliation Of Changes In Borrowings [Abstract]              
Balance at beginning of the year     R 7,921   7,538 0  
Loans raised     0   0 7,455  
Interest charge     380   389 36  
Interest paid     (376)   (385) 0  
Unwinding of amortised cost     318   298 27  
(Gain)/loss on foreign exchange differences     (952)   81 20  
Balance at end of the year     7,291   7,921 7,538  
Current portion of balance     (33) R (33) (37) (7,538)  
Non-current portion of balance     R 7,258 R 7,258 R 7,884 R 0