XML 64 R51.htm IDEA: XBRL DOCUMENT v3.20.2
STOCKHOLDERS' EQUITY: - Treasury Stock (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 153 Months Ended
Sep. 30, 2020
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Dec. 31, 2019
Activity in treasury stock          
Balance at the beginning of the period   $ 3,048.9      
Purchase of shares       $ 2,900.0  
Balance at the end of the period $ 3,048.0 $ 3,048.0 $ 3,039.9 $ 3,048.0  
Southern Copper common shares          
Activity in treasury stock          
Treasury stock balance at the end of the period (in shares) 111,522,817 111,522,817   111,522,817 111,537,217
Southern Copper common shares | Directors' Stock Award Plan          
Share Based Compensation Plan, share distributions          
Share Based Compensation Plan, share distributions during the period   14,400 14,400    
Parent Company (Grupo Mexico) common shares | Employee Stock Purchase Plan          
Share Based Compensation Plan, share distributions          
Share Based Compensation Plan, share distributions during the period   100,000 400,000    
TREASURY STOCK: | Southern Copper common shares          
Activity in treasury stock          
Balance at the beginning of the period   $ 2,767.9 $ 2,768.3    
Used for corporate purposes $ (0.4) (0.4) (0.4)    
Balance at the end of the period 2,767.5 2,767.5 2,767.9 $ 2,767.5  
TREASURY STOCK: | Parent Company (Grupo Mexico) common shares          
Activity in treasury stock          
Balance at the beginning of the period   281.0 251.3    
Other activity, including dividend, interest and foreign currency transaction effect   (0.5) 20.7    
Balance at the end of the period $ 280.5 $ 280.5 $ 272.0 $ 280.5  
Treasury stock balance at the end of the period (in shares) 90,947,011 90,947,011   90,947,011 93,082,532