STOCKHOLDERS' EQUITY: (Details) (USD $)	1 Months Ended			3 Months Ended	5 Months Ended	6 Months Ended	7 Months Ended	8 Months Ended	9 Months Ended	59 Months Ended					6 Months Ended				6 Months Ended
	Jun. 30, 2013	May 31, 2013	Apr. 30, 2013	Jun. 30, 2013	Dec. 31, 2008	Oct. 14, 2010	Oct. 31, 2012	Dec. 31, 2011	Sep. 30, 2009	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2013 Southern Copper common shares	Jun. 30, 2012 Southern Copper common shares	Jun. 30, 2013 Southern Copper common shares Directors' Stock Award Plan	Jun. 30, 2012 Southern Copper common shares Directors' Stock Award Plan	Jun. 30, 2013 Parent Company (Grupo Mexico) common shares	Jun. 30, 2012 Parent Company (Grupo Mexico) common shares	Jun. 30, 2013 Parent Company (Grupo Mexico) common shares Employee stock purchase plan	Jun. 30, 2012 Parent Company (Grupo Mexico) common shares Employee stock purchase plan	Jun. 30, 2013 TREASURY STOCK: Southern Copper common shares	Jun. 30, 2012 TREASURY STOCK: Southern Copper common shares	Jun. 30, 2013 TREASURY STOCK: Parent Company (Grupo Mexico) common shares	Jun. 30, 2012 TREASURY STOCK: Parent Company (Grupo Mexico) common shares
Activity in treasury stock
Balance at the beginning of the period											$ 918,791,000	$ 789,200,000									$ 729,800,000	$ 734,100,000	$ 189,000,000	$ 163,700,000
Purchase of shares	39,200,000	25,200,000	100,000	64,500,000	384,700,000	500,000	147,300,000	273,700,000	71,900,000	942,600,000											64,500,000	33,200,000
Stock dividend																						(151,400,000)
Used for corporate purposes																					(200,000)	(300,000)
Other activity, including dividend, interest and currency translation effect																							10,900,000	9,900,000
Balance at the end of the period	$ 994,039,000			$ 994,039,000						$ 994,039,000	$ 918,791,000	$ 789,200,000									$ 794,100,000	$ 615,600,000	$ 199,900,000	$ 173,600,000
Treasury stock balance at the end of the period (in shares)													41,167,836	35,751,686			77,832,273	83,709,360
Share-based Compensation Plan, share distributions
Share-based Compensation Plan, share distributions during the period															12,000	14,400			2,400,000	100,000