Equity attributable   Non-    
    Share   Share   Other   Retained   to owners   controlling    
Rm   capital   premium   reserves   profit   of the parent   interests   Total
                             
Balance as at December 2018 (Audited)*     2.2     139.1     729.6*     5,416.0*     6,286.9     14.6     6,301.5*
Dividends declared       174.3       (302.6)     (128.3)     (32.6)     (160.9)
Total comprehensive income         (68.8)     (1,307.5)     (1,376.3)     11.1     (1,365.2)
Changes in non-controlling interests         0.5       0.5     22.2     22.7
IFRS 2 charge and treasury shares acquired       (103.6)     102.4     3.9     2.7       2.7
                             
Balance as at December 2019 (Audited)     2.2     209.8     763.7     3,809.8     4,785.5     15.3     4,800.8
                             
Dividends declared               (39.9)     (39.9)
Total comprehensive income         20.8     (1,737.7)     (1,716.9)     (15.7)     (1,732.6)
Changes in non-controlling interests               0.5     0.5
IFRS 2 charge and treasury shares acquired       (86.9)     6.9     2.7     (77.3)       (77.3)
                             
Balance as at December 2020 (Reviewed)     2.2     122.9     791.4     2,074.8     2,991.3     (39.8)     2,951.5
                             
                             
* Balances re-presented by R227.1 million after taking into account the effect of the adoption of the IFRS 16 accounting standard.