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			62 Months Ended	1 Months Ended				9 Months Ended				9 Months Ended						3 Months Ended
	Sep. 30, 2013	Aug. 31, 2013	Jul. 31, 2013	Jun. 30, 2013	May 31, 2013	Apr. 30, 2013	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2012	Dec. 31, 2008	Oct. 14, 2010	Oct. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2009	Sep. 30, 2013	Oct. 31, 2012 Americas Mining Corporation ("AMC") merger transaction	Sep. 30, 2012 Americas Mining Corporation ("AMC") merger transaction	Sep. 30, 2013 Southern Copper common shares	Sep. 30, 2012 Southern Copper common shares	Sep. 30, 2013 Southern Copper common shares Directors' Stock Award Plan	Sep. 30, 2012 Southern Copper common shares Directors' Stock Award Plan	Sep. 30, 2013 Parent Company (Grupo Mexico) common shares	Sep. 30, 2012 Parent Company (Grupo Mexico) common shares	Sep. 30, 2013 Parent Company (Grupo Mexico) common shares Employee stock purchase plan	Sep. 30, 2012 Parent Company (Grupo Mexico) common shares Employee stock purchase plan	Sep. 30, 2013 TREASURY STOCK: Southern Copper common shares	Sep. 30, 2012 TREASURY STOCK: Southern Copper common shares	Sep. 30, 2013 TREASURY STOCK: Parent Company (Grupo Mexico) common shares	Sep. 30, 2012 TREASURY STOCK: Parent Company (Grupo Mexico) common shares	Sep. 30, 2012 ADDITIONAL PAID-IN CAPITAL: Americas Mining Corporation ("AMC") merger transaction
Activity in treasury stock
Balance at the beginning of the period														$ 918,791,000														$ 729,800,000	$ 734,100,000	$ 189,000,000	$ 163,700,000
Purchase of shares	5,600,000	17,100,000	35,900,000	39,200,000	26,100,000	100,000	58,600,000	65,400,000		384,700,000	500,000	147,300,000	273,700,000	124,000,000		71,900,000	1,002,100,000											124,000,000	132,400,000
Stock dividend																													(151,400,000)
Used for corporate purposes																												(300,000)	(300,000)
Other activity, including dividend, interest and currency translation effect																														12,900,000	24,100,000
Balance at the end of the period	1,055,432,000						1,055,432,000		902,600,000					1,055,432,000	902,600,000		1,055,432,000											853,500,000	714,800,000	201,900,000	187,800,000
Treasury stock balance at the end of the period (in shares)																				43,337,548	38,615,536			76,343,324	81,377,369
Share-based Compensation Plan, share distributions
Share-based Compensation Plan, share distributions during the period																						12,000	14,400			4,500,000	7,000,000
Delaware Court Decision Related to SCC Shareholder Derivative Lawsuit:
SCC shareholder derivative lawsuit payment received																																2,108,200,000
Legal fees related to SCC shareholders derivative lawsuit									316,233,000						316,233,000			316,200,000
Accrual - Legal fees related to SCC shareholders derivative lawsuit																			$ 316,200,000